AN ABSTRACT OF THE DISSERTATION OF Christopher John Stapels for the degree of Doctor of Philosophy in Physics presented on September 20. 2004. Title: Level Structure of '52Gd Populated in 152Th flDecay Abstract Approved: Redacted for Privacy As part of a research program to study the transitional region of N= 88 isotones, l52 was produced by the reaction '51Eu(a,3n)152Th in the 88" cyclotron located at LBNL. Gamma-ray spectroscopy of the radiation emitted from excited 152Gd following the j3f decay of '52Th has been performed using an array of 20 germanium detectors. The large Q-value (3990 keV) of the '52Th 2 decay allows for the population of many levels; study of coincidence and single events resulted in the establishment of 54 new levels and 266 new transitions. Angular correlation of the coincidences has determined spin and parity of many levels with several seen as key to the band structure, including two new 0 levels. One new rotational band including the new 1475.2 keV 0 level and the 1771.7 keV 2 level is proposed. The overall band structure compared to collective excitation models demonstrates the position of '52Gd in the transition from a spherical to deformed shape, also seen in other N =88 isotones. Monopole transition strength among bands indicates the possibility of mixing of both shapes among the excited states. The remarkable similarity of the band structure among these isotones is discussed. Level Structure of '52Gd Populated in '52Th fiDecay by Christopher John Stapels A DISSERTATION submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Presented September 20, 2004 Commencement June 2005 Doctor of Philosophy dissertation of Christopher John Stapels presented on September 20. 2004. APPROVED: Redacted for Privacy Majoi Professor, representing Physics Redacted for Privacy Chair of theDka4Itment of Physics Redacted for Privacy Dean of th 4IadIjate School I understand that my dissertation will become part of the permanent collection of Oregon State University libraries. My signature below authorizes release of my dissertation to any reader upon request. Redacted for privacy ACKNOWLEDGMENTS There are many individuals who have been crucial to the development or this work. The most influential of these include the following: My advisor, Dr. Ken Krane. Without the hundreds of hours of tutoring, explaining, editing, and reexplaining, I would have only have dreams of a completed thesis. My wife, Martha, who has continually encouraged me with love, supported me financially for the last several months, and gave me a goal to drive for by fmishing her PhD last year. Jeff Loats and Paul Schmelzenbach, my group members, provided a whole lot of the computer code I used, many critical discussions, and encouragement by proving that it is possible to graduate with these data sets. They also helped in the original experiment. John Wood of Georgia Tech. helped me understand much of the nuclear structure theory, and was vital to developing the band structure of' 52Gd, not to mention the fact that he made several trips to Corvallis to help with the interpretation of the data set for this work. David Kuip originally interpreted the data stream, and was the key person involved in gathering the data during the experiment. Dr. Corinne Manogue provided extra encouragement when I was thhildng of giving up. My committee members, Dr. Henri Jansen, Dr. Al Stetz, Dr. William Warren, and Dr. Mary Flahive have provided the academic guidance that I needed to complete my program at Oregon State University, including the wisdom to make sure I had a second try at my oral exam. Last, I thank my son Jonah for many smiles over the last ten months. Thank you to all of you for helping me achieve my goal. TABLE OF CONTENTS Chapter1 Introduction ............................................................................................ 1 Chapter 2 Emission and Correlation of EM Radiation ............................................. 4 2.1 Radiation field ................................................................................................ 4 2.1.1 Quantum mechanical description of the radiation field ........................ 6 2.1.2 Transition rates ................................................................................... 7 2.1.3 Weisskopf estimates .......................................................................... 10 2.1.4 Angular momentum and parity selection rules ................................... 11 2.1.5 Internal conversion ........................................................................... 13 2.2 y y coincidence rates .................................................................................. 15 2.3 Angular correlation ....................................................................................... 16 2.3.1 Angular correlation example ............................................................. 17 2.3.2 Angular correlation formalism .......................................................... 18 2.3.3 Multipole mixing .............................................................................. 19 2.3.4 Solid angle correction factors ............................................................ 22 2.3.5 Unobserved intermediate transitions ................................................. 23 2.3.6 Elucidation of spin and parity values ................................................. 24 Chapter 3 3.1 Nuclear Models .................................................................................... 27 Shell model .................................................................................................. 27 Shell model potential ........................................................................ 27 '52Gd in the shell model .................................................................... 29 Pairing and the spin predictions ......................................................... 30 3.1.1 3.1.2 3.1.3 3.2 Collective nuclear vibrations ........................................................................ 30 Theoretical description ...................................................................... 30 Spherical vibrator band structure ....................................................... 32 3.2.1 3.2.2 3.3 Deformation ................................................................................................. 33 Vibrations of deformed nuclei ........................................................... 35 3.3.2 Nuclear rotations in deformed nuclei ................................................. 35 3.3.3 Deformed rotational structure............................................................ 37 3.3.1 TABLE OF CONTENTS (Continued) Chapter4 Previous Work ...................................................................................... 39 4.1 Particle transfer studies ................................................................................. 40 4.2 Spectroscopy ................................................................................................ 41 4.3 Internal conversion (ICC) ............................................................................. 43 4.4 152Eu and I52mTb decay ................................................................................. 44 4.5 Angular correlations ..................................................................................... 44 4.6 Computational models .................................................................................. 45 Chapter 5 Experimental Description ..................................................................... 47 5.1 Source preparation ........................................................................................ 47 5.2 Detectors ...................................................................................................... 48 5.3 Angle relationships ....................................................................................... 50 5.4 Electronics ................................................................................................... 51 Timing .............................................................................................. 53 Coincidence pile up .......................................................................... 54 5.4.1 5.4.2 5.5 Data stream .................................................................................................. 54 5.5.2 Format .............................................................................................. 54 Errors in the data stream ................................................................... 56 Chapter 6 Analysis and Results ............................................................................. 58 5.5.1 6.1 Data sorting and calibration .......................................................................... 58 Timing .............................................................................................. 58 Scale down correction to singles ....................................................... 60 Efficiencies ....................................................................................... 61 6.1.4 Energy and width calibrations ........................................................... 65 6.1.1 6.1.2 6.1.3 TABLE OF CONTENTS (Continued) 6.2 Level scheme ................................................................................................ 66 6.2.1 Singles analysis ................................................................................. 66 6.2.2 Coincidence analysis ......................................................................... 67 6.2.3 Level placement ................................................................................ 71 6.2.4 Transition and level results ............................................................... 72 6.3 Comparison to previous results ..................................................................... 90 6.3.1 New levels ........................................................................................ 90 6.3.2 Newtransitions ................................................................................. 91 6.3.3 Upper limits on unseen transitions .................................................. 119 6.4 Angular correlation ..................................................................................... 120 6.4.1 Determination of correlation coefficients ........................................ 120 6.4.2 Matrix solution of distribution coefficients ...................................... 121 6.5 Mixing ratio (ö) calculation ........................................................................ 129 Previous mixing ratio measurements ............................................... 130 6.5.1 6.6 Determination of level spin ......................................................................... 132 1475.2keV0leve1 ......................................................................... 132 1681.1 keV0level ......................................................................... 134 1839.9keV34level ......................................................................... 134 6.6.4 1915.5keV3level ......................................................................... 134 6.6.5 Other spin assignments ................................................................... 135 6.6.1 6.6.2 6.6.3 6.7 E0 transition strength calculation ................................................................ 135 Chapter 7 Band Structure .................................................................................... 138 7.1 Nuclear structure model applications to '52Gd ............................................. 139 7.1.1 Quasirotational bands ...................................................................... 139 7.1.2 Ground state band ........................................................................... 141 7.1.3 Variable moment of inertia model ................................................... 143 7.1.4 Soft rotor ........................................................................................ 144 7.1.5 Anharmonic vibrator ....................................................................... 145 7.1.6 Interacting boson model (IBM) ...................................................... 147 7.2 Multipole transition strengths ..................................................................... 149 7.2.1 Monopole transition intensity .......................................................... 149 TABLE OF CONTENTS (Continued) Page 7.2.2 Relative B(E2) values in positive parity bands ................................. 151 7.3 Other bands and excited states .......................................................... Octupole states .................................................................................. Broken pair states .............................................................................. Shell model excitations ..................................................................... 7.3.1 7.3.2 7.3.3 Band structure systematics ................................................................ 156 7.4 7.5 7.5.1 7.5.2 8. 154 154 154 155 Conclusions ....................................................................................... 158 Summary ........................................................................................... 158 Further work ...................................................................................... 160 Appendix ........................................................................................... 161 Appendix I Energy sorted 7-ray list.......................................................................... 162 LIST OF FIGURES Figure 2-1 Spin 0-1-0 cascade showing possible rn-projections of the intermediate state ..... 17 2-2 Diagram for angular correlation with an unobserved intermediate transition ...... 23 2-3 Possible combinations of correlation coefficients A22 and A for correlations with 2 to 0 transitions for selected spin values of the initial level .................. 25 3-1 Two-neutron binding energy difference for some Gd isotopes ............................ 28 3-2 Band diagram for a theoretical spherical vibrator............................................... 33 3-3 Theoretical rotor band spacing........................................................................... 36 3-4 Theoretical deformed vibrational structure with quasi-rotational bands .............. 37 4-1 Low lying excited states for selected Z = 64 isotopes ......................................... 39 4-2 Comparison of ground-state and ybands of selected even Z, N= 88 isotones ..... 43 5-1 Inside the 8it detector ......................................................................................... 49 5-2 A schematic rendering of the relative placements of the crystals for the HPGe detectors inside the 8it detector........................................................................ 50 5-3 Angle relationships in the 8m detector array ....................................................... 51 5-4 Sample data stream from the 8m ......................................................................... 55 6-1 Sample time spectrum ........................................................................................ 59 6-2 Sample time difference spectrum ....................................................................... 60 6-3 '54Gd ground state rotational band ...................................................................... 62 6-4 Summed detector efficiency for singles and coincidences in the 8it .................... 64 6-5 Typical peak fit of singles data ........................................................................... 67 LIST OF FIGURES (Continued) Figure 6-6 Comparison of singles and coincidence spectra .................................................. 69 6-7 Coincidence intensity method ............................................................................ 70 6-8 Sample angular distribution fit ......................................................................... 122 6-9 Sample of X2 reduction method ........................................................................ 130 6-10 1130 keV gated coincidence spectrum showing 344 keV coincidence and feeding transitions ......................................................................................... 133 7-1 Positive parity band structure diagram for some low-lying states in '52Gd ........ 138 7-2 Energy levels for selected bands showing deviation from rotational spacing .... 140 7-3 The moment of inertia implied by a pure rotor for selected bands..................... 141 7-4 Low-lying members of the ground-state band of' 52Gd..................................... 142 7-5 Change in ground state band spacing due to VMI ............................................ 144 7-6 Partial level diagram showing B(E2) values that differ from the anharmonic vibrator ......................................................................................................... 147 7-7 Band structure diagram showing B(E2) values ................................................. 152 7-8 Selected B(E2) values for additional bands in '52Gd ......................................... 153 7-9 Negative parity bands in '52Gd ......................................................................... 155 7-10 Example of a single nucleon excitation across the Z = 64 subshell gap ........... 156 7-11 Comparison offlquasirotational bands for some N 88 isotones ................... 157 7-12 Comparison of ybands for some N 88 isotones .......................................... 158 7-13 Comparison of the "i" rotational bands in some N 88 isotones .................... 159 LIST OF TABLES ig Table 2-1 Approximate relative probability for emission of pure multipole transitions ....... 11 2-2 Selection rules for common multipoles .............................................................. 12 2-3 Q-factor calculation parameters.......................................................................... 22 5-1 Run numbers, scale-down factors, and time information for each data set created for this experiment .............................................................................. 53 6-1 Efficiency parameters describing the fits shown in Figure 6-4 ............................ 64 6-2 Level sorted transition list .................................................................................. 73 6-3 Comparison of published levels to those proposed in this work.......................... 92 6-4 Transition comparison........................................................................................ 97 6-5 Upper limits on transitions seen in Adam et al. but not seen in this work ......... 119 6-6 Angular correlation results ............................................................................... 123 6-7 Previously measured Svalues compared to this work ....................................... 131 6-8 Calculation of Uk factors using ratios of angular correlation factors .................. 137 7-1 Lifetimes and absolute B(E2) values, as reported by Johnson et al ................... 142 7-2 Electric monopole intensities JO for selected transitions and relevant conversion coefficients .................................................................................. 149 PREFACE Ernest Rutherford once wrote the following in a letter to A. S. Eve from his country cottage. He reported of his garden what he had also done for physics, vigorous and generous work: "I have made a still further clearance of the blackberry patch and the view is now quite attractive." I hope that statement can be applied at least in part to the subject of this work. From Richard Rhodes, The Making of the Atomic Bomb (New York. Simon and Schuster, 1986) Chapter 1 Introduction The composition and structure of nuclei is well developed but not fully understood. The profile of a three-dimensional plot of nuclear binding energy differences for nuclei of different numbers of protons (Z) and neutrons (N) reveals hints to the gross structure and makeup of the nucleus. Both peaks and valleys in such a diagram indicate significant bounds to nuclear properties and indicate points of interest for probing those properties. A valley in this diagram occurs for the N = 88 isotones those nuclei having 88 neutrons. '52Gd is one of these isotones, making it of interest to study. The nuclear structure determined by the energies of excited states can help elucidate these properties. Though the energy levels of an excited nucleus are determined by quantum mechanics, the many-body problem of 152 nucleons orbited by 64 electrons is beyond analytical solution. Some computational models have had varying degrees of success, yet the energies of excited states must be found experimentally by measuring the energy of radiation emitted during the decay of these levels. Study of the energies and relationships between levels nuclear structure provides an indication of the nuclear forces that determine the properties of all nuclei. Because nuclear excited states have definite angular momentum and parity properties, selection rules prohibit certain transitions between levels and enhance others. A heavy nucleus might have over 500 detectable yrays, thus the level scheme for such a nucleus can be a complicated maze of levels and transitions. Observing 2 emitted radiation with a single detector will indicate only the energy and intensity of radiations. Coincidence spectroscopy observing multiple radiations within a given time window indicates the relationships of different transitions in the level scheme. Many models have been developed to explain the observed level schemes. Further development and testing of these models requires the study of nuclei at the extremes of the model parameters. Often, these nuclei must be created artificially. Many of the artificially producible isotopes were originally studied during the rapid expansion of nuclear structure investigations in the 1950's to the 1970's. Since then great developments in detector resolution and efficiency have been made. Along with these changes has come a proliferation of multiple-detector arrays for coincidence y detection. Large improvements can now be made above and beyond on the data previously collected on artificial isotopes. Specifically, the detector array used in the present work has this ability. '52Tb decays by decay - the emission of a positron during the conversion of a proton into a neutron. The daughter nucleus that is the result of this decay is '52Gd. Since the total energy of' 52Tb minus the byproducts of the beta radiation is greater than the ground state energy of'52Gd, the daughter is left in an excited state. In recording the relationships of the energies emitted as decays to the ground state, some patterns emerge. The onset of nuclear deformation above A = 150 makes the study of '52Gd especially interesting. Doubly-even nuclei with 80-86 neutrons are generally thought to have spherically shaped ground states and excited states with a spherical equilibrium. At N = 90, the excited states of nuclei begin to exhibit properties consistent with a deformed shape. Thus the N = 88 isotones are often deemed transitional. Study of the patterns of excited states in these nuclei can help develop models for both spherical and deformed nuclei. This thesis involves '-ray energies and coincidence information recorded by a 20 detector array observing a '52Tb sample decaying to '52Gd. The data have suggested many new transitions and excited states in the 152Gd level scheme. Angular correlations of coincident yrays have determined or restricted angular momentum and parity assignments for many of these excited states. Nuclear structure models are applied to the results to infer the character of the '52Gd nucleus. Chapter 2 of this thesis describes the emission of electromagnetic radiation by nuclei and describes the angular correlation formalism. Some aspects of applicable nuclear models are described in Chapter 3. An overview of previously published work relating to the structure of '52Gd and similar nuclei, along with some pertinent conclusions of these authors, is contained in Chapter 4. Chapter 5 describes the details of the experimental apparatus and the format of the collected data. Methods of analysis are presented in Chapter 6. Lists of the excited states determined and all the observed transitions between those levels are included. The levels and yrays are also compared to the most recently published results. Chapter 7 deals with patterns seen in the low-energy levels or band structure in comparison to specific models and to the surrounding nuclei. 4 Chapter 2 Emission and Correlation of EM Radiation 2.1 Radiation field The electromagnetic radiation emitted from a nucleus is the basis of this study. In order to extract the maximum amount of information from the radiation, it is necessary to understand the nature of the radiation. Nuclear levels in general have well defined angular momentum and defmite parity. Electromagnetic radiation connecting levels also is seen to have these properties. Maxwell's equations provide a fundamental description of the electric and magnetic components of the radiation field. V XE + =0, V.E=4ffp, at 2-1 VxB=4j, V.B=0. Far from the nucleus, p and j are zero. The vector potential and a scalar potential are required to link the electric and magnetic fields: B=VxA, 2-2 E=VcI. 2-3 at Combining Maxwell's equations with these potentials produces the inhomogeneous wave equation that describes electromagnetic radiation fields (in Coulomb gauge): 5 2-4 it V A =0 (Coulomb gauge). The scalar potential version of 2-4 2-5 is: V2(r,9,q5,t)_r0øt) =0. 2-6 t2 The solutions to the scalar wave equation are building blocks for the corresponding vector equation. The solutions are obtained by separation of variables. The radial parts can be solved by spherical Bessel functions and the angular parts by the spherical harmonics. L,M (r,9,Ø,t) = L,M(r,O,ø)e L has positive integer values L terms of the EM field, L is 0, 1, 2, 3,... and M= 0, ±1, ±2, k is ±L. In the angular momentum carried by the field, while Mis its projection on some chosen z-axis. The value w is the frequency of the The value 2-7 = jL(kr)YL,M(9,ø)e°t. EM radiation. used to match the radial solution to the boundary conditions. It has units of inverse distance. Using the proper vector and differential operators, the scalar solution can be transformed into a solution of the vector wave equation. These vector wave equations have defmite parity. The two possible parities give rise to two different types of electromagnetic radiation fields: magnetic (M) and electric (E). The gradient operator alone changes the parity of a vector field, but does not produce a solution to the vector wave equation. Since the parity depends on the angular momentum, the angular momentum operator produces solutions with the proper vector and parity properties.' In natural units (h = m = c = 1), the vector potential can be written as 1 A(M) L,M LLM(r), 2-8 L(L + 1) 1 L,M k..jL(L+1) (VxL)GLM(r), 2-9 L=ihrxV. 2-10 An EL (ML) transition refers to radiation with electric (magnetic) type parity and L units of angular momentum. A 7-ray transition connecting two states can be a pure multipole or consist of a combination of several multipolarities. 2.1.1 Quantum mechanical description of the radiation field The vector field description of the electromagnetic field allows transition probabilities for EM radiation to be written th terms of quantum mechanical matrix elements. The matrix element that describes the transition probability for emission of multipole2 radiation is (J1m j(r ')A I Jm1) from an initial state of total angular momentum (spin) .1, and projection m, to the state .Jj with projection mj. The symbol j (r') is the nuclear current density operator 2-il 7 It is often simpler to write the matrix elements in terms of the multipole operators1, 1 (2L+1)!! 7si(ML,M) L (L+1)[I+1)I1 (2L+1)!! 1(EL,M) (OL(L+1) [L(L+1)] Jj(r')A(r') Jj(r')A(r 2-12 2-13 The transition matrix elements can be written in terms of the multipole matrix elements: (Jfmf j(r')A(r')Jm1) = 1 i (Jfmf (2L + 1)!! The value of 2-14 kL U 0 for .ir= E, and 1 for r= i1(L, M) Jm1) M Transition rates 2.1.2 The Wigner-Eckart theorem allows the transition matrix elements to be written in a simplified form that separates the element into a geometrical factor due to the angular momentum change of the transition, and a reduced matrix element due to the remaining nuclear force moderated parts of the transition probability.2 (Jfmflj(r1)AJjmj)=(_1)3mf( Jf L J(Jjj(r1)AJj), m1 _Mm) The Wigner 3] symbol is defmed by' 2-15 (i 12 (_1)i2 13 m1m2m3 (j1m,j2m2 j3-rn3). 2-16 (2j3+1) or, in terms of the 3] symbol in 2-15, LJ [Jm1Mm. (1Y'm' (Jj,m1,L,M J,_m1) 2-17 (2J1+1) It is frequently useful to compare transition strengths without the energy dependence. The reduced matrix elements defined in 2-15 allow such a simplification. The commonly used reduced transition probability is B(L,JJ1)= The B (,rL, .1, -i II(2L)IIJ 2-18 (2+1) is important in determining structure since it depends only on the nuclear parts of the transition matrix element. The total transition probability' contains the energy and angular momentum dependant factors: 8,21 (L + 1) [(2L+1)!!)]2 L B(irL,J J1). 2-19 Since electric quadrupole transitions are the most common in transitions between nuclear collective states at low excitation energy, the B(E2) reduced transition probabilities are often an aid to determination of the nuclear structure. The average time for a decay to take place is directly related to the strength of the transition matrix element so the reduced transition probabilities can be determined if the half life is known. Using 2-19 and noting that the transition rate is related to the half-life, the B(,rL) can be written as3 h(hcj B(2rL;JJf)= L[(2L+l), 2L+1 ln(2) 2-20 rpartic 82T(L+1) 7 For a half-life in seconds and energy in keV, the B(E2) in units of e2b2 has a simplified4 form: B(E2)= 56.4 1/2 2-21 E5 The partial half-life is the total half-life of an excited state divided by the fraction of the decays that occur by the tray process of interest. In the B(E2), the process of interest would be transitions ofE2 multipolarity. For example, for a level that decays only by one transition that consists of E0, Ml and E2 multipolarities, the total half-life can be written as TMl.ub0l TEoPct 1/2 + 1/2 TE2,Phic + 1/2 , 2-22 fE2 where f is the intensity of a transition that involves a given multipolarity divided by the total intensity of transitions from the same level. Due to the difficulty of measuring times in the picosecond and shorter range and the problem of isolating yrays from a particular level, few lifetimes of excited states have been measured. Table 7-1 lists the all the measured absolute B(E2) values for transitions in '52Gd. The reduced transition probabilities for transitions from a common level can be compared. The normalized B(E2) values from a given level are an indication of the reduced nuclear matrix element in 2-18. The relative B(E2) is calculated using the 10 intensity I7of the transition of interest, the percentage of that transition that involves the E2 multipolarity %E2, and the energy E in any convenient units: B(E2)1 (%E2)Ir C. 2-23 The value C is a normalization factor determined by making the strongest B(E2) from a level equal to 100. 2.1.3 Weisskopf estimates Since the wavefunctions of nuclear states are generally not known, it is not generally possible to get the transition rates directly from 2-19. If the assumption that the radiation is due to one nucleon moving from one shell-model orbit to another is made, an estimation of some transition rates for certain types of radiation is possible (for a description of the shell model, see 3.1). These estimates are known as the Weisskopf or single-particle estimates. Using the transition rate 2-19, a simplified form for the radial dependence, and estimating the spin and angular parts of the integral to be unity the transition probabilities can be estimated for the lower multipolarities5 B(EL)W = 4,r A2''3, L+3) B(ML)W =(l.2)22( 2-24 2-25 Table 2-1 shows the most common type of multipole radiations and approximate strengths determined by Weisskopf estimates6. The many simplifying 11 assumptions made to develop these estimates make them useful only as a rough guideline to multipole strength. The af' energy dependence in 2-19 has been included in these estimates to highlight the differences in strengths. 2.1.4 Angular momentum and parity selection rules The total angular momentum of a nuclear state is the sum of orbital angular momentum and the nucleon spin. The combination is commonly referred to as simply the spin Jof the nuclear state. Since similar nucleons pair to form states of total angular momentum zero, the spin is generally due to only the unpaired nucleons. The angular momentum quantum numbers Jand m3 of a nuclear state and of the multipole radiation are considered definite and determine the allowed transitions from levels of spin-parity J to J. The change in spin is constrained by the multipolarity of the 'y-ray emission. Table 2-1 Approximate relative probability for emission of pure multipole transitions6 Multipolarity Description El Electric Dipole Electric Quadrupole Electric Octupole Magnetic Dipole Magnetic Quadrupole E2 E3 Mi M2 Approximate relative emission probability (in s1 for E in MeV) 1 .Ox 1 014A213E3 7.3x1O7A413E5 34A2E7 5.6x10'3E3 3.5 xl 7 A213E5 12 2-26 M=m1mf. 2-27 The multipole fields also have well defmed parity. This determines the parity change of a given multipole transition. (_1)t ;ir1. = (-1)' (magnetic multipoles), 2-28 (electric multipoles). 2-29 A summary of the possible change in spin (J) and parity (sr) for the most common multipole transitions is depicted in Table The selection rules in Table 2-2 2-2. and the rapid decline of multipole strength with increasing L seen in Table 2-1 allow coincidence information to be an aid to the determination of the spin and parity of a level. For example, transitions with L infrequently observed. If L = 2 is feeds a O level can at most be a 2 are taken as the highest multipole order, a level that state (2 is unlikely since the parity change would Table 2-2 Selection rules for common multipoles Multipolarity > 2 Possible Ar EO 0 0 El 0,1 1 E2 0,1,2 0 MI 0,1 0 M2 0,1,2 1 j 13 require an M2 transition). If a transition from that same level to a 4 level is found, the spin and parity of the original level is almost certainly 2. Even where the spin and parity cannot be unambiguously determined by this method, it is often able to limit the choices to only a few spin and parity combinations. 2.1.5 Internal conversion Overlap of the electronic wavefunctions with the nucleus can provide other channels for the excited nucleus to release energy. The transfer of energy directly to the electrons in various shells is known as internal conversion. For transition probability T(e, n/c) for electron emission and T() for remission, the conversion coefficient is defmed as' T(e, nic) T(v) ' 2-30 where n is the principal quantum number and K indicates the angular momentum quantum number of the electron shells. The total conversion coefficient is the sum of the coefficient for each shell: a= 2-31 Since the K-shell orbitals have the most overlap with the nucleus, these electrons have the largest conversion coefficients; the conversion coefficients decrease approximately as 1/n3 for higher electron shells.6 The internal conversion process can involve any multipolarity and uniquely uses E0 (there are no E0 'y-ray transitions). The E0 transition refers to zero change in 14 angular momentum for an electric (K) type transition. The diagonal elements of the multipole operator 2-13 for the EO process are directly related to the mean square radii.7 Since EO transitions indicate a change in the mean-square radius of the nucleus and not the spin, nuclear levels with large EO components indicate the possibility of largely different shapes. Such transitions can be an important determinant of different coexisting shapes in the nuclear structure. The EO multipolarity intensity of a transition that involves EO + E2 + MI can be calculated if the experimental (XJ( and the mixing ratio for E2/M1 are known. The aK designation isolates the effects of electronic transitions from the K shell. The experimental (rK can be expanded into terms specific to each multipole8: 1E0 1 82 2-32 The aMI and aE2 are the ratios of internal conversion by MI or E2 to the total v-ray intensity. The term 1° in 2-32 describes the intensity of electron emissions that involve EO. The a's depend on the multipole operators and the electron wavefunctions; they can be calculated since the electronic wavefunctions are well known. Online computer codes9 can be used to generate these coefficients for input Z and E1 values. In cases where the half-life of the level has been measured, it is possible to calculate the EO transition strength. The EO electron intensity is used to calculate the partial half-life 15 I+I01a1 Tb'o rbotal 1/2 x ,EO 2-33 ' which depends also on the total gamma ray intensity I, and the total internal conversion intensity L1, L11, L111, jbotal which includes the intensity due to all the electron shells K, M etc. The EO transition strength p2(EO) depends on the partial half-life of the level with respect to EO. 1 p2(EO) 1/2 The K 2-34 K are due to the electron wavefunctions and are available from Bell et al)° The EO electron intensities for selected yrays from the present experiments are shown in Table 7-2. 2.2 'y y coincidence rates In general, determination of the level structure of the nucleus requires the simultaneous (within a small time window) detection of two 'yrays. Inmost nuclei, including '52Gd, the lifetimes of nuclear excited states are generally in the femtosecond range, although some are as long as a few nanoseconds. In a relatively strong source of 1 jiCi, the average time between decays is on the order of tens of microseconds. Two yrays from this source that are detected within a time window of a few nanoseconds are much more likely to be from the same nucleus than two different nuclei. A level scheme for a nucleus can thus be created by detecting multiple simultaneous radiations with only a small correction for accidental 16 coincidences. The rate of collection of individual coincidence events can be calculated based on the source strength. The efficiencies for detecting i and b are e, and describes the ratio of the number of i events to total decay events ratio of y, and 'Y2 (b e2. The value describes the coincidence events to total events). The rate R depends on the activity A: Rsng =e,Ab, 2-35 =e,e2Ab. The accidental coincidence rate depends on the activity squared: Racnc in a time window of width 2.3 = e2A2t, 2-36 t. Angular correlation The probability of emission of radiation depends on the angle between the quantization axis and the direction of propagation of the radiation. Therefore, observing the direction of radiation as a function of angle indicates the spins of states that are connected by that transition. Such a measurement is defmed as a directional distribution.'3 To measure the distribution requires some orientation, or a preferred axis, which produces an unequal distribution of rn-state orientations of the nuclear spins. The direction of one radiation in a cascade of coincident transitions from a single nucleus can be used to fix the orientation of the nucleus, as in this experiment. In this 17 case, the angle between two radiations is measured and the measurement is defined as an angular correlation. 2.3.1 Angular correlation example The defmite angular momentum and parity properties of pure multipole transitions give a characteristic angular dependence to the radiation (due to the spherical harmonics) depending on L and its projection M For dipole radiation, M= 0 radiation varies as sin29, and M= ±1 radiation varies as 2(1+cos29). For example, a ray transition from a state of J = F to = 0 is pure electric dipole (El), with an angular distribution that varies depending on z.m. Figure 2-1 shows the three possible projections (m) for the spin(J) of the initial state: -1, 0, and 1. With no preferred jr J1 p 7 = =1 =0 Figure 2-1 Spin 0-1-0 cascade showing possible rn-projections of the intermediate state 18 orientation, each m state is equally populated, and the intensity of emitted radiation W(G) is independent of a W(0)oc 2[ W i]+Wm = 2[I(1+cos2 O)]+sin2 0 = 2. If another transition from a J O state to the 2-37 = 1 state is observed first, the emitted radiation determines a preferred axis for quantization. The angle 0 is defmed as the angle between the two observed yrays, with the 0= O direction defmed by the first yray. The distribution is the same as the original distribution for m = 0 and Am = 1, with respect to 0 = 0. The sin20 dependence of the Am = 0 transition forces the observed Y2 transitions to have Am = ±1. And, therefore, the distribution of the radiation with respect to the direction of 21 (angular correlation) is now the sum of two Am = 1 distributions that depends on Oas: W(0) oc 2.3.2 2[WAm I] = 2[(1+cos2 0)] = 1+cos2 0. 2-38 Angular correlation formalism The previous example indicates how rotating the quantization axis from the direction of one radiation to the other produces a correlation between 21 and that depends on the angle between them. The general case of two successively detected y rays can be written in terms of independently weighted Legendre polynomials. The resulting angular distribution equation is 19 W(0)=N APk(cosO), 2-39 k=even where N is a normalization constant and the Akk are weighting factors known as the angular correlation coefficients. The circular polarization angular distribution contains a sum over the emitted photon's helicity states r= +1,-i of the form ik. In this experiment the circular polarization is not measured, so the angular correlation is a sum over the helicity states, which leaves oniy even terms.'3 (2 fork even'\ rk__l+(_l)k=0fOrkOddJ. 2-40 When no polarization measurement is made, the angular intensity is independent of the parity of the transition. The highest term in 2-39 is determined by the angular momentum selection rule" kmax =Min(2J,,2L1,2L2). L, 2-41 and L2 refer to the angular momentum of the largest observed multipoles in the first and second transition, respectively. For the majority of nuclear transitions, the highest possible order is quadrupole, thus the angular correlation contains terms in P2 and P4 only. In transitions where the selection rules demand pure or relatively pure multipolarity, the An and A44 have distinctive values. For example, the correlation between the transitions of a spin 4+ - 2 + - 0+cascade involves almost pure E2 multipolarity. The expected A22 value is nearly 0.1 and the A44 is approximately 0. 2.3.3 Multipole mixing 20 In cases where the selection rules allow more than one multipolarity, there are generally only two major competing components. For example, in a spin 0 - 2 2 cascade, the first transition (0+2) is pure E2, but the second (2*2) can be a combination of E2 and MI radiation (see table 2-1). The experimentally measured A22 and A44 will then depend on the amount of each multipolarity present, which is defined by the mixing ratio The mixing ratio is written so that the numerator is always the multipolarity with the larger L. For parity iv and iv' = E or Mand wave number k, (+1 (IMOTL ')II) k :L!L i 2-42 (J+1Hi1(7r'L)IIJ) Forexample,E2,M1 mixinghas L' =2,L= 1, ir=E, and iv' = M Themixingratio is a function of both the multipolarities of the transition and the initial and final spins of the states connected by a given transition. The analysis of mixed multipole transitions is simplified by recasting the angular distribution function into products of factors depending on each transition in a cascade separately. In the case of coincidence with in direct in a cascade from JjJ2J3: W(9) = B(y)A(y2)PjcosO). 2-43 The Bk and Ak can be written using the reduced matrix elements2: Bk (ri) L,rL,t F(L1IJ1J2)(1)h1' (2 IJNALJIJI X2 iNAL1 JI) 2-44 (J2 IIJNAII L1,r1 ll' 21 Fk(L2L2J3J2)(J II. 311JN Ak(72) L2r2L2,r2 AJ2)(J A°J) 311JN L2 L2 2-45 . 2 L2 V Ar2J2)311JN The Akk is the product of the two factors: A=Ak(y2)Bk(yI). 2-46 The F-coefficients determine the angular momentum dependence of the angular distribution. The F-coefficients have been tabulated and are available in convienient tables.'2 The have the following form'3, in terms of the 3] symbol, which is defmed in 2-16: Fk(LL 'J2J,) = (_1)J2' [(2k+1)(2L +1)(2L +1) (2J, +i)]2 (L xl ' k IL L' k 1 1 O)J, .J, 2-47 k J2 The symbol in braces{}is a 6fsymbol, as defined in Edmonds.'4 The effect of the 6fsymbol is to recouple the possible angular momenta in terms of different orderings of the J. The single-transition angular correlation factors Ak and Bk can be simplified in terms of the F coefficients and the mixing ratio ö: Ak B (LLJfJ)+28(y)F(LLJfJ)+ö2((L?LhJfJ) 1+82(y 2-48 F(LLJJ)-28(7)F(LL'J1J1)+ S2(y)F(L'LJ1J,) 1+2(y) 2-49 The form for Ak and Bk as a function of 8provides limits on the initial and final 22 fof the transitions j'j and determine the mixing ratio . If thef are known, then the Ak and Bk can be used to In this experiment E2, Mi and M2, El mixing ratios were measured, the most common case being E2, Mi multipole mixing. 2.3.4 Solid angle correction factors The angular correlation formalism described in 2.3 assumes that each detector is small enough so that the angle between two detectors is an exact number. The experimental situation deviates from the theory due to the fmite sizes of the detectors and the relatively small source to detector separation. The solid angle correction factors Qk correct for this deviation. When Qk (Yi) and correction factors for and Qk (72) are the respective in a distribution measurement, 2-43 can then be written as: W(9)NQk(y)Qk(y2)Bk(y)Ak(y2)F(cos9). 2-50 The Qk used in this experiment were calculated using the computer method of Krane.15'16 The estimated average values used in the program are shown in Table 2-3. Table 2-3 Q-factor calculation parameters IDescription Radius Length Dead layer thickness Value (cm2J 2.45 5.7 0.3 23 The calculated correction factors vary slowly with energy so the Q2 and Q4 factors were only calculated for every 100 keV. The resulting product Qk ( ) Q (12) = approximately 2.3.5 Q had similar values over a large range of energy. The values were Q22 = 0.985 and Q = 0.95 1. Unobserved intermediate transitions When the lifetimes of the intermediate states are relatively short, correlations between 7rays not immediately in succession can be used to calculate multipole mixing. Figure 2-2 shows a sample case where the angular distribution of j ang could be measured without observing . Ji Ji (Vu) J2 72 Jf Figure 2-2 Diagram for angular correlation with an unobserved intermediate transition. 24 The deorientation coefficient Uk accounts for the effects on the correlation due to unobserved transitions. In such a measurement the correlation function 2-50 is written as W(0)= NUkQkkBk(yI)Ak(y2)Pk(cos6). 2-51 The deorientation factors are Uk(J!,J2,L) (_1)u12 1.i, [(2..,, +1)(2J2 +i)] J, L 2 They have been tabulated for common tables.'2 J1 , , kj> 2-52 L and are available in published In cases where the unobserved transition has a mixture of multipoles, the 8 value must be measured by a direct correlation measurement or previous experiment. The adjusted U coefficient for such a case is a weighted average of the Uk (J1, j2 , L) for both dominant multipoles L and L' in the mixed transition: Uk(JI,J2)= 2.3.6 Uk (J,, J2 , L) + 52Uk (J, , __ , L') 1+82 2-53 Elucidation of spin and parity values In certain cases, the angular correlation coefficients can be used to deduce the spin of an excited level. When one of the transitions in a correlation is a pure transition, the process is somewhat simplified. Figure 2-3 shows the allowed 25 combinations of A22 and A44 for transitions with spin 1, 2, and 3 feeding a 2 to 0 transition. In these plots oranges from -5 to 5. Two experimental pairs of correlation coefficients are shown: the 2365-344 keV correlation and the 1441-1109 keV correlation. The 2365-344 keV correlation clearly indicates spin 2 of the initial level. The experimental data falls very near 5 = 0, so nothing can be said about the parity. Correlation coefficients for selected spin cascades - - -2-2-0 0.2 3-2-0 0.15 * -1-2-0 S t 1441-1109 4. 01 I -e-- 2365-344 I i 4-2-0 IT -0.8 0.4 I -0.2 0.6 0.8 A22 Figure 2-3 Possible combinations of correlation coefficients An and A for correlations with 2 to 01 transitions for selected spin values of the initial level. Moving along a given curve represents a change in 8, the curves are approximately symmetric about 8= 0. Although the angular correlation measurement is independent of the parities of the levels involved, a measurement of Scan often indicate the change in parity. For a transition where there is a parity change from the initial to the final level, the dominant multipolarities are El and M2. The Weisskopf estimates in Table 2-1 show that El is favored over M2 by about a factor of 100, thus S(M2/El) should be small if there is a parity change. A large measured mixing ratio indicates a Sof the form S (E2 I Mi) where the multipoles involved are E2 and Mi. Since E2 and Mi transitions cannot change the parity of a state, a large Sgenerally indicates no change of parity from the initial to the final state connected by that transition. For example, the transition from the 2539 keV to the 344 keV level has 5 -1.4. 2195 keV Since the 344 level has positive parity, the large absolute value of the mixing ratio indicates that the 2539 keV level also has positive parity. Table 6-2 shows the resulting 3 assignment. 27 Chapter 3 Nuclear Models 3.1 Shell model The observation of sudden discontmuities in nuclear properties suggests a description of nucleon orbitals in terms of discrete shells, similar to the atomic orbitals of electrons. For example, the nucleon separation energies and nuclear radii exhibit sudden changes at particular numbers of protons or neutrons.6 This is clearly shown in plots of two-nucleon separation energies (S2, S2) which are directly related to binding energy differences. The changes observed in two-nucleon separation energies at closed shells are strong indications of an underlying shell structure in the nucleus. Figure 3-1 shows the closed shell at 82 neutrons, occurring near the 88 neutron nucleus '52Gd, as a drop in the S2. The slight increase in energy after N = 88 is due to the onset of deformation. The position near the onset of deformation is a major motivation for interest in the '52Gd nuclear structure. Nuclear excitations in the shell model can be explained as individual nucleons being promoted to higher shell model orbitals. This version of the shell model is called the single-particle model. 3.1.1 Shell model potential The nucleus can be modeled to first order as a finite square well. However, the S2 of some Gd isotopes 21000 19000 17000 15000 13000 11000 76 78 80 82 84 86 88 90 92 94 96 98 100 N Figure 3-1 Two-neutron binding energy difference for some Gd isotopes.17 The value S2 = BE(N,Z) - BE(N-2,Z). nuclear mass distribution at the surface is not as sharp as a square well. More detailed forms of the nuclear potential can do a better job of modeling the actual nucleus, but require numerical solution methods. The harmonic oscillator potential has a similar basic shape, but has less sharp edges and also has analytical solutions. A coupling between the spin of the nucleon and the angular momentum of its orbit is apparent and adding such a term gives energy gaps at numbers that match the discontinuities (such as seen in Figure 3-1). A negative term proportional to 12 counters growth in the potential for high values of angular momentum 1. The shell model potential can be written as: 29 V(r)=Mw2r2 +ClL+D12 2 3-1 Shell model orbitals are indicated by the oscillator quantum number N and the orbital angular momentum 1, the total spinj (j 1 ± s), and the directional component of total spin in. The angular momentum is denoted by a letter sequence s, p, d, f, g, h,... corresponding respectively to 1= 0, 1, 2, 3, 4, 5... Since the Pauli exclusion applies only to identical particles, protons and neutrons fill shells independently. Each level is 2j+1 degenerate, corresponding to the different projections of the total spinj (mi). The calculated energy levels of the shell model potential closely match the actual energy discontinuities at and 126. 2, 8, 20, 28, 50, 82, These numbers indicate the number of protons or neutrons required to create a closed shell; they are known as 'magic numbers'. Nuclei with numbers of protons or neutrons far from magic numbers exhibit properties that diverge markedly from those near magic numbers. 3.1.2 152Gd in the shell model The nucleus '52Gd has 64 protons, thus contains full g7/2 and d512 subshells. A small energy gap occurs at 64 protons. While the gap at 64 is not as large as the energy gaps at the magic numbers, 64 is a relatively stable number of protons. The 88 neutrons, however, give just over a half full h912 subshell, and 6 neutrons away from the closed shell at 82. The properties seen outside closed shells are consistent with extra nucleons polarizing a spherical core. The nuclear deformation increases as more 30 nucleons beyond a closed shell are added. 3.1.3 Pairing and the spin predictions Pairing of spin (s = '/2 particles) to achieve a total angular momentumJ= 0 is seen in many systems such as in Cooper pairs in a superconductor. Protons and neutrons are fermions with intrinsic spin '/2, and they also tend to pair and form quasi- boson pairs with J = 0. It is safe to assume that nuclei with even numbers of protons or neutrons have their angular momentum paired. Thus, the ground state spin of all even-even nuclei such as '52Gd is zero. Even-odd nuclei have ground state spins determined by the unpaired nucleon. Doubly odd nuclei can couple the two unpairedj values with values from 1 j2J tojj, +J2. While the shell model is successful at predicting the magic numbers and spins of excitations in nuclei near closed shells, the single-particle theory breaks down in regions away from magic numbers. For example, many nuclei in the region above A = 150 have first excited 2 states at energies below the single-particle excitation energies. Collective nuclear models have been postulated to explain this discrepancy. 3.2 Collective nuclear vibrations 3.2.1 Theoretical description Nuclear vibrations are one type of collective nuclear motion. The vibrating nuclear surface can be represented as a sum over spherical harmonics with time- 31 varying amplitude: r p=2 a(t)Y(G,çb) R(9,Ø)=R01 1+ L 2=2 fl-2 1 3-2 I A change in oo corresponds to a change in the nuclear volume, which is a much higher energy process than the shape vibration. Placing the center of mass at the origin forces a = 0. Thus, the lowest low-energy mode is the quadrupole vibration which involves changes in a2. The Hamiltoman for a vibrating nucleus can be quantized in the form: 3-3 HVIb = + .). The product /I counts the number of vibrational phonons N in a nuclear state. The energy of the vibrator is then: EN =h(D(N+.) 3-4 For a single phonon excitation, the spin of the excited state equals 2, which is the spin of the vibrational phonon. Multiple phonon excitations have total spins that range over the different possible ways to couple spin 2 bosons symmetrically. For N = 2, for example, the spins of the excited states can be 0, 2, or 4. Comparing the energies of low lying states can often indicate a particular model. The ratio of the energy of the lowest 4 state to the lowest 2 state for a vibrating nucleus is thus expected to be: R E(41) = 2.00 E(21) 3-5 32 where the subscript 1 of 4 refers to the lowest energy 4 level, and so on. 3.2.2 Spherical vibrator band structure The possible coupling of vibrational phonons leads to only certain possible spin values with a distinct pattern. The right side of Figure 3-2 provides a basic diagram of some of the expected levels of a purely quadrupole vibrational nucleus. The electric quadrupole operator1 contains only one-phonon annihilation and creation operators: 1(E2)=_ZeRo)2(t+), 36 where C is the restoring force constant for quadrupole vibrations of the nucleus, Z is the number of protons, e is the electron charge and R0 - 1.5 fin is the average nuclear radius for A = 1. Since the operators in 3-6 appear only singly, E2 transitions in the vibrational model will have LN = 1. Due to this restriction, the possible levels shown on the left of Figure 3-2 can be loosely organized into the bands seen on the right. Nuclei exhibiting exact vibrational behavior do not exist, although there are many examples that resemble this pattern. The triplet of O, 2, and 4 states at twice the energy of the first 2 state is a strong indication of vibrational structure. Furthermore, the B(E2; N*N-1) values predicted by the vibrational model are proportional to N. Thus, B(E2;4 2)= 2xB(E2;2 Or), 3-7 33 4 3+ ______ 64+ 2k-'_____ o+J 4+ 2 0 ______ 0 0k-' 2 2- 2 0 Figure 3-2 Band diagram for a theoretical spherical vibrator. The groups of states at higher energies are nearly degenerate. "4Cd and '°2Ru are often considered to be good examples of vibrational nuclei, they have values for B(E2;4, *2,)IB(E2;2, *O) of 1.99 and 1.47. Harmonic vibrational motion is more often not observed. The observed spectra seem to indicate that it takes only a few valence nuclei to soften the nucleus to deformation enough that the simple spherical vibrator loses applicability.'9 3.3 Deformation As described in 3.1, adding protons or neutrons beyond the "magic" numbers, tends to change the nuclear shape. This deformation changes the types of collective modes allowed. Deformation can be modeled in terms of a change in the (static) 34 amplitude of a spherical harmonic. Based on empirical evidence, the deformation is generally taken to be primarily of quadrupole type, thus the nuclear surface is written in the form: Ro[1+a2flY(6'øt)]. R 3-8 The primes indicate a rotation from the space-fixed to the body-fixed axis. After performing this transformation, the a20 and a22 can be parameterized'8 in terms of/land I a20 =flcosy, 3-9 1 a22 =.-=flsiny. 3-10 Choosing the body-fixed frame to be the principalaxes forces and a22 a21 a21 =0 a2,_2. The parameter flis related to the deformation of the nucleus: fl2a2 The parameter yspecifies the axial asymmetry: y = 3-11 , , and 0, are prolate (cigar-shaped) ellipsoids with the 1, 2, and 3-axes as symmetry axes respectively. When ' 57i. r, and r the shapes are oblate (pancake) shapes with the same symmetry axes respectively. 35 3.3.1 Vibrations of deformed nuclei Vibrations of deformed nuclei are described in terms of time-dependant variations of/i and yabout non-zero equilibrium values. A /3 vibration preserves the axial symmetry of the nucleus; this change can be modeled by compressing the ends of a football-shaped object. The yvibration breaks the axial symmetry; compressing the top and bottom of the football approximates a yvibration. The /3 vibration carries zero units of angular momentum, the yvibration carries two units of angular momentum. The structure seen for a deformed nucleus is often a rotating structure built on vibrational states. 3.3.2 Nuclear rotations in deformed nuclei A second class of collective motion is rotations of the nucleus. The increasing static deformation of nuclei with A? 150 makes such rotations observable. If the nucleus has a moment of inertia 3, then the Hamiltonian for an axially symmetric rotor has analytic solutions with the energy eigenvalues'9 E=--[J(J+1)K(K+1)], 3-12 where K is the projection of J onto the body-fixed axis. Within a rotational band, K constant, and K(K-i-1) 23 can be combined with the mtnnsic energy of the band E0. The energies within a band are is 36 E =E0+J(J+1). 3-13 23 With the energy spacing of 3-13, the ratio of the 4 state to the 2 state in a rotational band is distinctly different from the vibrational spacing seen in 3-5: E(41) R4 3-14 E(21) Higher levels in this pattern will have a spacing based on the first excited state in the band. For A = --, the 2 level is expected at 6A, the 4 at 20A, and so forth, as illustrated in Figure 3-3. Ground-state rotational bands of strongly-deformed nuclei have excited states that fit the spacing implied by 3-13 to very high values of total spin (J). Once again we fmd no nucleus that is a pure rotor, but the match here is significantly better than 6 + 42A 20A 2 0 Figure 3-3 Theoretical rotor band spacing. 6A 0 37 the pure vibrator. 3.3.3 Deformed rotational structure If the ground state of the nucleus or an excited state has a permanent deformation, patterns of nuclear levels increasing in spin connected by a change of rotation built on the deformed vibrating structure are common. For an axial symmetric nucleus, bands with a spin o band head, such as the ground state band, have only even spins. Thus the ground state rotational band has spins O, 2, 4 etc. The bands of deformed nuclei exhibit patterns consistent with rotational bands built on vibrational phonons. Experimentally, the level spacing in these bands usually does not 2 4+ 4+ 0 6 4, 0 g.s. f3 y 13J3 Figure 3-4 Theoretical deformed vibrational structure with quasi-rotational bands. match the expected J (J+ 1) rotor spacing as well. The quality of K as a quantum number and the potential for mixtures of configurations from different band structures are thought to be the cause. Vibrational levels built on a O fl-vibration have a similar spin pattern as the ground state band: 0 2, 4, etc. A band of rotations built on a yvibration can have any integer spin larger than two: 2, 3 4 etc. The deformed rotational model fits the data qualitatively well, though once again, there is no perfect match. Vibrational modes will mix so that the bands are not truly as separated as indicated in Figure 3-4. The mixing causes closely spaced levels to repel, leading to non-rotational spacing in energy. The actual band structures of many nuclei generally have features of both vibrations and rotations. The nucleus '52Gd which lies at the onset of deformation displays clear characteristics of both collective models. 39 Chapter 4 Previous Work As described previously, the primary motivation for the study of '52Gd comes from its placement in the midst of a transformation from spherical to deformed structure. Data compiled34 from studies o.f several gadolinium isotopes, for example, demonstrate this trend. As pairs of neutrons are added to gadolinium isotopes, the nearly vibrational spacing seen in '48Gd becomes the clearly rotational pattern of the low-lying levels in '56Gd and beyond. The change is evident moving from left to right in Figure 4-1. 4-,-2500- 2000 2 1500- 6- 6 4-,-- 6 + (keV) 22 ftTrs 500 6k- 6 + + 4+ + + 6 - 4 - 4__+ - 0 ' 0 O 0 0 O 02+_O+_Ø+ Gd 148 Gd 150 Gd 152 Gd 154 Gd 156 Gd Gd 160 Gd Figure 4-1 Low lying excited states for selected Z = 64 isotopes. The progression from vibrational to rotational structure is apparent from left to right. 40 The majority of the published work on the nuclear structure of '52Gd describes its structure in relation to the onset of deformation. 4.1 Particle transfer studies Resonances in particle transfer reactions are often seen as indications of collectivity. Flemming et al. measured (p,t) reactions on even gadolinium nuclei.20 The 0 excited states at 615 keV and 1048 keV are strongly populated in the reaction '54Gd(p,t)'52Gd. The population of these excited states indicates a shape transition in gadolinium isotopes at N = 88 as seen in Figure 4-1. An earlier paper by the same group21 describes the lack of 0 states in '54'58Gd from (p,t) reactions leading to a similar conclusion (that '52Gd has collective attributes). The population of the 615 keV state in '52Gd was observed with nearly the same strength as the ground state, and this is evidence for the transition into "quasirotational" nuclei. The quasirotational or "soft" nature of what is called the flvibration in '52Gd can explain the enhanced population of the 615 keV state. They also describe that the second excited 0 state at 1048 keV is enhanced due to overlap with the '54Gd ground state. The enhancement indicates the presence of both a spherical and a deformed shape in the '52Gd excited states. EIze et al. also measured the results of(p,t) reactions in gadolinium isotopes.22 Both Flemming and Elze indicate the similarity of the dual excited 0 states in 152Gd to '50Sm which is also anN= 88 isotone. Deuteron scattering (d, d') on gadolinium isotopes is also used to investigate rii collective states. All the excited states seen in the deuteron experiments have a corollary in '50Sm except the 1047 keV level. Several spin and parity assignments consistent with collectivity and with previous measurements result from the (d,d') scattering performed by Bloch et al.23 4.2 Spectroscopy Many studies have described the nuclear structure of 152Gd from the decay of '52Tb, including Gromov et al. ,24 Kormiciki et al. ,25 Harmatz et al. ,26 Strigachev et al.,27 Basina et al.,28 Frana et al.,29 Toth etal.,3° Flerov etal.,31 and Adam et al.32 The defmitive spectroscopy work, published by Zolnowski et al. placed over 290 transitions in the level scheme. They describe a band structure (including previously published bands) of nine bands, two with negative parity. The low-spin members of the ground-state band are observed, along with a quasi-fl band based on the 0 615 keV level. Large observed E0 transitions are given as evidence for the K = 0 assignment for this band. The 1047 keV level is described as the head of a quasi-2fl band. They note the difference in the observed B(E2) values of this 2fl band compared to 2/1 band B(E2) values in '54Gd; the difference is due to the spherical nature of 52Gd (compared to the deformed '54Gd). The quasi- yband described begins with the 1109 keV level, the lack of substantial E0 admixture in the 765 keV transition from this level leads to a K = 2 designation. A two-phonon flyband made of the 1605 keV and 1839 keV levels is chosen based on preferential decay to members of the one phonon bands. The 1862 keV level is tentatively described as the second member of a 3/1 42 band with the 1484 0 state observed by Adam.32 Observation of this level has yet to be confirmed. The 1941 keV level is postulated as a flfl coupling to produce a K = 2 band. Two negative parity bands are described in the Zolnowski paper. A band built on the 3 level at 1123 keV is assigned K= 0 while the 1643 keV level at 2 starts a K = 1 band. The expected separation of the octupole vibration into K = 0, 1, 2 , and 3 components is not fully realized, but the first two negative parity bands fit this prescription well. Zolnowski et al. describe the striking similarity of the structure in this region that is the motivation for the present study. This similarity can be seen in the comparison of severalN= 88 isotones in Figure 4-2. All data in the figure are from the Nuclear Data Sheets (NDS) as reported online by the Table of Radioactive Isotopes34. Note the almost identical ground state bands even over a change of 8 protons. The Zolnowski compilation remained the most complete report until a newer paper35 by Adam et al. was published in 2003. Adam reports over 131 new transitions between the excited states of 152Gd and introduces 46 new levels into the decay scheme. The NDS36 compilation of the '52Gd spectroscopy is based primarily on Zolnowski's data, and predates the recent Adam paper. The NDS compilation provides energy, spin, level placement, mixing ratio, and conversion electron data evaluated from all available sources. The more recent paper by Adam et al. does not propose any new band 43 _ (10 10 1 ± (6 - 8 (5 - _ (8 4f (2 - (6 + y - 4+ 4 4_ 0 ' Ce gs. 148 Nd g.s. 150 Sm g.s. 152 Gd gs. Dy g.s. Figure 4-2 Comparison of ground-state and ybands of selected even Z, isotones. N = 88 structure. They do use several different models to predict the ratios of the energies of excited states. Their conclusion is that the quadrupole phonon model has the best predictive value for '52Gd, and that this nucleus is either at or very near to a phase transition from a spherical to deformed shape. 4.3 Internal conversion (ICC) The conversion electrons were first measured by Antoneva et aL37 Conversion 44 coefficients are generally taken from the earlier Adam paper32, though Gromov also published internal conversion data. 24 The more recent Adam paper has reanalyzed the older data using newer v-ray intensities. Gono et al. also measured conversion electrons and T-rays with a focus on the 931 keV level.38 All calculations using experimental conversion coefficients in this document use the values in the more recent Adam et 4.4 al. 152Eu and paper.35 lszmTb decay Many papers have reported on the '52Gd decay populated by 152Eu39'40'41'42'43'44 and from lS2mEU4S46,47 decays. Zolnowski and Hughes et al.48 measured the spectroscopy of l52mTb. The lS2mTb has a 4.2 minute half life and f=8. Bowman et al. also measured this decay much earlier, and included some quasirotational band assignments.49 4.5 Angular correlations Angular correlation and distribution measurements have been published by six groups. Kalfas and Hamilton50 used yyangular correlations, low temperature nuclear orientation (LTNO), and '.ray conversion electron angular correlation experiments to determine the angular correlation parameters and mixing ratios for five transitions. Ferencei51 used LTNO to measure 8for 34 transitions. Additionally they conclude that the variations in measured values cannot be completely described by the rotation- vibration model. Lipas et al.52 measured six mixing ratios using LTNO. The most 45 recent and comprehensive work is that of Tagziria et al.53 who also used LTNO to measure anisotropies with two detectors. They reported mixing ratios for 45 transitions and upper or lower limits for 14 more transitions. Asai and Kawade54 describe a method for using five detectors and the resulting -ycorrelation to determine angular correlation parameters. They provide a sample ofA22 and A for three transitions. A comparison of the results is provided in Table 6-7. The major disagreements in the chart arise most often due to a difference in the spin and parity assignments in the initial or fmal levels when compared to other experimental results. 4.6 Computational models Published results of model predictions of energy levels, mixing ratios, reduced matrix elements and other nuclear parameters are extensive for 152Gd. There have been many attempts to describe the character of 152Gd using models based on refmements of the rotational and vibrational models described in chapter 3 One set of models is referred to as the interacting boson approximation (IBA) or the interacting boson model (IBM). The nucleus treated as if it were composed of nucleon pairs, or bosons. The bosons can be of two types, either s bosons, with spin 0 or d bosons with spin 2. An interaction Hamiltonian is postulated, and then solved to fmd the level energies. More details of the model are presented in 7.1.6. The IBA-1 model treats protons and neutrons exactly the same, where the IBA-2 accounts for them separately. The Lipas et al.53 paper concludes that the IBA- 1 model is overextended for 46 152Gd. Another Lipas et al. paper calculates mixing ratios for a few transitions, though no general comments about the structure are made.55 Chu et al. 56 apply the IBA- 1 to the N = 88 isotones, they find improved results when including higher spin levels to determine the model parameters. They also note the similarity of the '52Gd level structure to 150Sm almost every level with assigned spin and parity has a matching partner within 150 keV. Several other studies57'58'59'6° apply IBA-1 across a range of nuclei including '52Gd. One interesting result of Kern et al. is the prediction of a 0 state at 1425, near the new 0 level at 1475 seen in this work.6' Han et 62 al. applied the same model to the negative parity states in N = 88 isotones. The IBA-2 model has also been applied to calculate systematics across this region.63'64'65 These models have had widely varying levels of success; none approach a close fit of different parameters across a broad range. 47 Chapter 5 Experimental Description 5.1 Source preparation The original target used to produce the excited states '52Gd was enriched '51Eu powder. The powder has an isotopic purity of 98.6%. The powder was slurried with a few drops of water and then dried with a heat lamp onto a 5 cmx5 cmx 0.1 cm Al foil. The first foil was then covered by a second foil and the ends folded to create a package containing the '51EU The package was irradiated in a beam of a particles produced by the Lawrence Berkeley 88" cyclotron. Several Al degrader foils were placed in the beam upstream of the target to produce the optimal beam energy at the target. The optimal energy was chosen for producing '52Tb by the reaction 151Eu(a, 3n) '52Tb while minimizing 151Eu (a, 2n) 153Tb and '51Eu (a, 4n) '51Tb. The final parameters chosen were an abeam energy of-42 MeV with three aluminum degrader foils in front of the target. The resulting '52Tb has a 17.5 hour half-life and decays by fl emission. The activity was allowed to cool for a period of time determined by the total beam current that the packet received. This time was generally a few hours. After cooling, the radioactive powder was dissolved in HC1 to create a liquid sample. The liquid was placed in a plastic vial 8 mm in diameter and 5 cm long, and then transferred to the 8rt detector for counting. Samples were counted for approximately one half-life, after which fresh activity was added to the sample to keep the counting rate high. This 48 process was repeated for approximately one week (99.5 hours online time), producing 8.68 GB of data, on the order of 108 total single events. Several competing reactions produce contamination. Substantial amounts of '51Tb, '53Tb, and 154Tb were created in the sample as well. These also decay to Gd by fidecay. 5.2 Detectors Radiations from the source were recorded by 20 HPGe (High Purity Germanium) detectors with an average resolution (FWHM) of 2.7 keV at 100 keV to 4.5 keV at 2.8 MeV. The detectors have volumes ranging from 95 cm3 to 127 cm3 with front face diameters from 49.4 to 53.5 mm. The efficiencies varied considerably from one detector to another. The efficiencies of 18 of the detectors normalized to 344 keV have standard deviation at 2.5 MeV of approximately 40%. The efficiencies for detectors 13 and 18 vary by a factor of 2 from the median value at 2.5 MeV. The detectors are numbered in the data stream from 0 to 19. A major benefit to the 8it detector array is that each detector has a Bismuth Germinate (BGO) Compton suppression shield. The shields serve to cancel events that deposit only some of their energy in the detector and scatter into the Compton shields. The Compton suppression shields cover only the sides and rear of the germanium detector crystals but result in a large increase iii the peak to background ratio, especially in the low energy region of the spectrum. The peak to Compton ratio for the whole array is approximately 28, as measured in several gated spectra for 49 several different energies. The detectors are positioned so that their surfaces sit approximately on the face of a common sphere. The source was placed at the center of the sphere so that the source to detector separation was approximately 20 cm. At this range, the detectors actually cover only about 10% of the total solid angle. A photograph of the inside of the detector array can be seen in Figure 5-1. Figure 5-2 shows.a schematic diagram showing the relative placements of the germanium crystals. Inside the sphere of HPGe detectors was another spherically shaped shell of BGO scintillator detectors. Figure 5-1 Inside the 8ic detector. Half the detectors have been removed to show the detector positioning. The BGO ball has also been removed. 50 These detectors were not used in this experiment. 5.3 Angle relationships Through there are 190 unique detector pairs in the array of 20 detectors, the symmetry of the detector positions provides for only 5 unique angle pairs: 41.80, 70.5°, 109.5°, 138.2°, and 180.0°. 30 pairs of detectors form the angle 42°, 30 pairs have 138° between them, 60 pairs have 71°, 60 pairs have 109°, and 10 pairs have 180° between them. The number of detector pairs that form a particular angle occurs Figure 5-2 A schematic rendering of the relative placements of the crystals for the HPGe detectors inside the 8m detector. 51 in the ratio 3:6:6:3:1 with respect to increasing angle. The detector angle relationships are indicated in a matrix format in Figure 5-3. Note that each detector appears the same number of times in each angle. Thus in the first order, parameters specific to a particular detector can be divided out. 5.4 Electronics The electronics supporting the detectors were originally designed to record the events from in-beam scattering experiments, and were somewhat modified during the Detector # 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 0 -nnuiinunn -nanniinn 2 3 4 5 -giniiiign 6 7 8 nncrnñ IIflNUII1I 0 10 a) 011 12 13 14 15 16 17 18 __EI -EInnhI1In UflBEI -IIIfl -II 19 Figure 5-3 Angle relationships in the 8ir detector array. The matrix is symmetric; the bottom half has been removed for readability. 52 present experiment. The supporting electronics recorded the energy of events recorded by the detectors, and the multiplicity for events that were coincident within a time window. The time from the start of an event to each yray in a multiplet was also recorded. It is important to understand the specifics of the data recording method in order to appreciate the format of the data and the modifications that were required. Determining the level scheme for a nucleus requires information about the relationship of different transitions in that scheme. The spectra of single events or "singles" are necessary only to determine the efficiency for the sum of all detectors in the array and for each detector separately. Placing a yray in the level scheme requires information about which events occurred simultaneously. Thus coincidence data is of higher value than the singles data.66 Unfortunately, coincidence events are less likely to be detected than singles data as seen in 2-35. Since 82 is generally on the order of icr3, the coincidence rate is generally low with respect to singles. The electronics included a dual triggering device that distinguished events of multiplicity one (singles) from those events with multiple yrays, in order to enhance the collection of coincidence data with respect to singles data. A scale-down component rejected all events for recording as singles data until the scale-down setting had been reached. Thus a setting of 100 would reject 99 events and record the 100th Some modification of the data was necessary due to the fact that the scale-down box incremented for each yray, including those that are part ofa coincidence event. The entire procedure for modification and sorting of the data is described in 6.1. Since coincidence events count two yrays from the same decay, the singles as recorded by 53 the 8ir have proportionally more counts for a peak in coincidence than a true single detector would. The scale down factor (SDF) was chosen to keep the amount of singles data from overwhelming the data recording system. Thus the scale down setting for each run was determined by the source strength. Table 5-1 records the SDF and basic infonnation about each of the 11 data sets recorded. In almost all analyses, the runs were combined into a single data set. 5.4.1 Timing Timing electronics recorded the time from the beginning of an event as seen by the master trigger device to each individual yray in that event. Events that occur Table 5-1 Run numbers, scale-down factors, and time information for each data set created for this experiment. Run Number 1.1 2.1 2.2 2.3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 I SDF Time (br) 62 62 62 62 126 126 8.0 10.5 11.83 11.73 40 256 256 96 32 2.45 10.0 3.5 4.0 14.0 14.0 9.5 I Date fmished 10/26/99 10/26/99 10/27/99 10/27/99 10/28/99 10/28/99 10/28/99 10/28/99 10/29/99 10/29/99 10/30/99 54 without another v ray within the time window were delayed from zero by 25-40 ns in order to allow separation of single events from coincidence events by using the timing information. 5.4.2 Coincidence pile up The common usage of pile-up in y.ray counting refers to two events close in time in the same detector. The 8it electronics created another type of pile-up event which needed to be corrected for. If a single detector detects more than one yray during the time another detector takes to process a single 7-ray, a coincidence pile up condition is created. The resulting event will have only a single 7-ray but timing information similar to a coincidence event. The initial data sorting routing removes these events due to improper event length. However, the software that generates the singles spectra uses the count of pile-up events in order to create an accurate efficiency spectrum. 5.5 Data stream 5.5.1 Format The data stream was stored in a file buffer on the collection computer and then written in binary format on 8-mm tape. Each event has the same basic structure. A representation of a section of the data is shown in Figure 5-4. Each column represents a two byte binary word converted to base 10. The bold section represents one event. 55 The first numbers contain information about the BGO detectors; in this experiment those first three numbers written are always zero. The next number is the multiplicity or number of yrays in the time window, which generally varies from 0 to 4. The bold event shown in the figure has multiplicity two. The next section varies in length based upon the multiplicity. For each y ray in the event, the detector number, the energy of the y ray (in channels), and the time from the start of the event (in channels) are listed. The list starts with the event that has the lowest detector number (0-19) not necessarily the first yray to arrive. The length of this section is three times the multiplicity. The bold text in the figure indicates an event with detector 8 having energy 688 and time 129 channels in coincidence with an event in detector 15, energy of 390, and time 144 channels. Energy and time channels refer to the channel number on the multi-channel analyzer connected to a detector or its timing electronics. The energy spectrum is 8 k 0001120 0001140 0001160 0001200 0001220 0001240 0001260 0001300 0001320 104 65535 129 15 0 14 0 16 0 6 2 8 364 688 0 0 0 0 0 0 0 0 0 0 8 0 0 0 0 15 0 0 2 6 132 65534 103 65535 0 0 0 0 0 275 1984 0 0 0 390 384 496 438 689 1996 144 103 128 140 105 144 65535 65535 65534 65535 65535 0 0 0 8 2 0 12 Figure 5-4 Sample data stream from the 8it. The leftmost colunm represents the line numbers in the text file. or 8192 channels. The energy channel calibration is described later, but is very near 0.5 keV per channel. The time spectrum was 4096 channels in length, but generally only recorded events within 100 us of each other.4 It was unnecessary to calibrate the time channels absolutely; however, the gain was approximately 1 ns per channel. The fmal number is the end of event (EOE) flag: 65535 or FFFF in hexadecimal. 5.5.2 Errors in the data stream Previous investigations of the data stream from other data sets gathered with the same apparatus found several recurring deviations from the standard data format.4'66 These errors were also found in the data set used for the 152Gd investigation (this experiment.) For an unknown reason, the data stream exhibited dropped bits at certain points in the data. Since the data is written in binary, one easily distinguishable consequence of a dropped bit is that odd numbers are turned to even numbers. Since the length of an event is detennined by the multiplicity, if an event were to have been dropped bit in the multiplicity, the event length would not match properly (there would be more detector, energy, and timing information than expected.) While the sort program was written to reject events with the improper length, short events do not seem to be due to dropped bits in the multiplicity. Less than 0.02% of events were removed due to improper length. Dropped bits in the energy resulted in some even-odd staggering in the data, especially apparent at high energies. To remove this problem, the energy scale was 57 cut in half. The result is that the even and odd channels were summed, which removed the staggering at the cost of resolution. No similar even-odd staggering was observed in the detector number or the energy spectra. The EOE flag was the other major place where dropped bits were observed. In this case, the EOE flag is written as 65534. The second to last event in figure 5-2 shows this problem. The sorting program was written to accept 65534 as an EOE flag, and the frequency was recorded. The frequency of the EOE dropped bit varied considerably from run to run, though was as high as 34% in some runs. 1:1 Chapter 6 Analysis and Results 6.1 Data sorting and calibration It was necessary to sort the data for analysis. Utilizing previously written code4 as a substantial building block, a program was written in C++ to sort the data. The sorting program split each data set into two files: one containing singles events (multiplicity 1) and one containing coincidence events (multiplicity 2). Triple and quadruple coincidence events were written as three and six independent coincidence events (for all possible-permutations.) Since higher multiplicity events have much lower statistics, they are a small part of the coincidence data set. 2.1% of all data are triple events and 0.07% are quadruple events. 6.1.1 Timing Separating singles and coincidences required adjustment ofthe timing data. Differing cable lengths and other delays in the timing circuitry caused the singles timing peak in the data stream to be written in slightly different channels for each detector. It was necessary to determine an offset for each detector and shift the timing data accordingly. After adjusting for the offset, events with a time within a sevenchannel-wide gate around the singles timing peak were counted as singles. A sample time spectrum is shown in Figure 6-1. 59 rj/ 2o Channe's Figure 6-1 Sample time spectrum. The calibration for the x axis is approximately 1 ns per channel. Though the lifetimes of most of the nuclear states in '52Gd are in the range of picoseconds or smaller, the offsets described above and other delays in the coincidence electronics separated coincident yrays in time. The time window for the master trigger (to decide if events were coincident) was about 100 ns long. The histogram of the time difference between the later and the earlier 7-ray in a coincidence event is called the time-difference spectrum. These spectra were used to filter out some of the accidental events. It is clear in the time difference spectrum (Figure 6-2) that there is a sharp drop-off at approximately 60 channels, followed by a relatively flat background. The flat background indicates chance coincidences (or accidentals) while the higher counts below 60 channels are composed of true coincident events. The two peaks between 35 and 60 channels are from pile up and other not clearly resolved events. The time cut was taken at a difference of 35 channels to avoid these events. The result is that coincident 7-rays are those that [ I C Chnnes 1-.IC C W Figure 6-2 Sample time difference spectrum. The time cut at 35 channels is shown by a vertical line. The calibration for the x-axis is approximately 1 ns per channel. were less than 35 ns apart in the recorded data stream. It is often the case in coincidence experiments that the flat chance background is used to subtract a background of accidental coincidences from events with a time difference indicating coincidence. In the 8it data in the configuration used at LBL, the time window is too short for the background to truly become flat. Furthermore, the background lacked the necessary statistics to make this procedure possible. Instead, an adjusted singles spectrum was scaled and subtracted from each spectrum. This process is described in 6.2.2. 6.1.2 Scale-down correction to singles The singles files were used primarily for calibrating the efficiency and energy of the detectors and of the array as a whole. Due to the method for separation of multiplicity 1 and multiplicity > I events by the electronics, transitions that were p 61 commonly in coincidence pairs were more likely to be recorded as single events. Furthermore, pile-up and dead time rejection is more likely for more intense events. Therefore, the singles files had to be corrected before they could be used for an accurate efficiency calibration. The adjustment to the singles counts was achieved by adding the coincidence file to a scaled number of the singles events. A scale factor was determined by modifying the hardware scale-down factor (SDF) for the events it undercounted. The effective scale-down factor (ESDF) has the following form: ESDF = SDF (CNC + PU), SNG 6-1 where CNC, PU, and SNG refer to the total number of coincidence events, pile up events and singles events in a particular detector, for a certain data set. The resulting spectra, referred to as true singles, were created by multiplying the singles spectrum by the ESDF and then adding coincidence and pile up counts. The fmal spectrum was then rescaled to match the original singles data. A summed true singles spectra was created for each detector and for the entire array. 6.1.3 Efficiencies The true singles spectrum was used to generate efficiency parameters for the whole detector array. The intensity values of several of the peaks reported by Zolonowski33 were used to create values of the relative efficiency over the entire range of energies. Higher intensity peaks were chosen based on their separation from other 62 peaks and their spread across the dynamic range of the detectors. There are few low-energy transitions in the 152Gd spectrum, and none with large intensity. Unfortunately, the efficiency changes rapidly with energy at lower energies. However, the '54Tb contamination decays to a rotational band cascade in '54Gd with several peaks in the low energy region leading to the 123.1 keV transition. The cascade is shown in Figure 6-3. A coincidence gate was taken on the 426.7 keV peak to isolate these transitions. The relative intensity of peaks in that cascade in the resulting coincidence spectrum varies from the actual intensities only by the efficiency. Recent data on the 8 1144.4 426.7 6+ 717.7 346.7 371 .0 4+ 247.9 2 0 123.1 123.1 Figure 6-3 '54Gd ground state rotational band 0.0 63 relative strength of transitions in that cascade was used to produce efficiencies in the low energy region.67 The number of counts in the 346 keV peak was nonnalized to equal the efficiency of the 344 keV peak in the '52Gd. Combining the '52Gd peaks and the '54Gd data produced efficiency values across a wide range of energies. A fourthorder polynomial was fit to the logio (efficiency) vs. logio(energy) plot. Later in the experiment it was found that the 8ic detector, in the configuration of this experiment, recorded very different efficiencies for singles events and for coincidence events as seen in Figure 6-4. Although the exact cause is not understood part of the difference is due to the effect of the scale down factor explained in 6.1.2. To develop a proper coincidence efficiency curve, the efficiencies taken from strong peaks in direct coincidence with the 344 keV and 411 keV y-rays were normalized to match the '54Gd data taken in the manner described above. The piecewise matched data were fit with the same procedure as the singles data to produce efficiency parameters. These parameters were used for adjusting coincidence intensities. The resulting fits are shown in Figure 6-4. The coefficients for the polynomial fits plotted in Figure 6-4 are provided in Table 6-1. The efficiency of each detector was calculated in a similar manner using the singles data separated by detector. The coincidence matrix generated by the original sort code removed detector information, so a new projection of the coincidence data for each detector was necessary. The gated spectrum for the '54Gd efficiency data consisted of all transitions in a single detector that were coincident with any other detector recording the 427 transition. The single detector efficiencies were necessary 64 10.00 Singles Vs. CoincIdence Efficiency ya*Iog(E)4+b*Iog(E)s3+c*log(E )A2+d*log(E)+e 1.00 i 000 ' F H'- 0.10 sngfit Cnc fit Log [Energy] (key) Figure 6-4 Summed detector efficiency for singles and coincidences in the 8it. A polynomial fit to log(efficiency) vs. log(energy) for singles data and coincidence data, normalized at 344 keY is shown. Table 6-1 Efficiency parameters describing the fits shown in Figure 6-4. Sng effpann. Cnc effparm. a -1.5518 -2.0566 b 18.4685 23.8070 -81.9544 -102.8205 159.9937 195.5189 -115.6941 -137.7717 65 to adjust the number of counts detected in a particular angle pair (in angular distribution.) The standard deviation of the efficiencies calculated for the points chosen for the singles fit is approximately 3%. This number is taken as a lower limit of the efficiency error. 6.1.4 Energy and width calibrations The energy calibrations were determined by comparing the locations of 15 intense peaks to the energies provided by the Table of Online Radioactive Isotopes68 (TORI). The entire data set was gain-shifted to align the centroids of those peaks with the accepted values. The average deviation from the accepted values for those strong peaks in the gain-matched data is less than 0.1 keV. In general, the deviation in energy calibration is due to higher resolution that allows detection of weaker peaks that are not separated in previous data. Width parameters are important for separating closely spaced peaks. Peak width parameters were developed for each detector, for singles data, and for coincidence data. The different width parameters were used at various stages of the analysis. In the fmal analysis, one consistent set of width parameters was required for consistency. The following equation for full width at half maximum in channels is derived from a combination of several fits. FWHM2 = 2.732 + 0.082x + 1.322x2, 6-2 where x 6.2 E 1000 with E7in keY. Level scheme 6.2.1 Singles analysis The peak areas in the summed singles spectrum from all runs and all detectors (about 766,315,264 counts) were determined first. The analysis started at higher energies (3-4 MeV) and progressively decreased in energy. This strategy was chosen in order to fit the less complicated parts of the spectra first, and thus develop a robust method that would help deal with the complexities at lower energies. Figure 6-5 shows an example of this complexity. The relative simplicity at higher energies is due to the fact that the energy of any decay is limited by the Q -value. The sum of the ray energy and the energy of the level it decays to must be less than the total energy available for the decay. Thus the higher-energy y-rays can decay only to the ground state or low excited states. Deducing the coincidence relationships for these transitions is somewhat simpler. In many cases the singles spectrum was too complicated to fit directly. The coincidence data were often used to determine the exact peak locations to be given as fixed parameters in the fit of the singles data. 6.2.2 Coincidence analysis Using the fit results from singles data, gates in the two-dimensional data were 'pulled' for each peak. This process consisted of defming a gate window width, and choosing background windows above and below the gate window to subtract from the coincidence spectrum. Software was developed that determined the number of counts in each background window, calculated a slope, and subtracted a linearly approximated background from the coincidence gate window proportional to the summed counts in the background window. The strong sources used in this experiment produced a relatively high ratio of 74.O Figure 6-5 Typical peak fit of singles data. The ordinate has a log scale of number of counts with fit residuals shown between the abscissa and the peaks. accidental to true coincidences. The ratio was determined to be approximately 0.09. A singles spectrum scaled to 9.9% of the total counts in a raw coincidence spectrum was subtracted to account for accidental coincidences. The power of coincidence gates is especially potent in cases where there are several closely spaced peaks in the singles spectrum. Some peaks that could not be seen at all in the singles data could be clearly resolved in the coincidence data. Gates as small as two channels wide were pulled across a complicated doublet or triplet to resolve its constituent parts. A sample of the resolving power of coincidence gates is shown in Figure 6-6. 62.2.1 Measurement of absolute intensities Absolute intensities for the strongest peaks were determined from the singles spectrum. The error from summing smaller unresolved peaks is generally much less than the statistical error for a large peak. In general, weaker peaks are much harder to resolve in singles data. The majority of the intensities were determined by coincidence. If several transitions feed the same level, as seen schematically in Figure 6-7, the ratio of intensities in a coincidence gate for a transition that depopulates that level is the same as the ratio of absolute intensities. If the absolute intensity of one of those transitions can be determined from the singles data, it can be used to normalize all the other relative intensities. The normalization is N J(sng) 6-3 gate AB (cnc) cm Figure 6-6 Comparison of singles and coincidence spectra. The upper spectrum is the summed singles and the lower is a composite of the 411 keV gate (dashed) and the 586 keV gate. where 'B is the singles intensity of spectrum produced by gating On in direct coincidence with coincidence spectrum. Ygate Ygate. and AB is the area of y in the coincidence The intensity of another yray (such as depends on Ngate in 6-3 and AA, the area of or lc) in the flate 70 6-4 'A = NgaAA(cnc) In a few cases (approximately 10 out of 620) is was not possible to determine the absolute intensity of any transitions in any gate appropriate for a given weak transition. In this case the normalization was determined using below flate a transition in the level scheme. Assuming there are no other ways to get from the level depopulated by flate to the level it feeds, the intensity of spectrum will be equal to the measured intensity of ate e1ow in the 2ate The normalization in this case is Nga 'y(gate) (sng) 6-5 AT(beIow) (cnc) where 'y(gate) is the singles intensity of 2'gate and Figure 6-7 Coincidence intensity method. 4(below) is the area of that yray in the 71 coincidence spectrum produced by gating on Ygate. Uncertainties in the intensities result from a cautious 5% uncertainty in the efficiency (Ueff), the fit uncertainty determined by Radware for the peak of interest (Uk), and the fit uncertainty for the peak used to determine the normalization (Unorm). Since the uncertainties are unrelated, the sum of squares is used: = Ju + The uncertainty for the method using + u. 6-6 described above is increased by 10% to adjust for the possibility of alternate paths from the intermediate level in Figure 6-7 that do not include 6.2.3 Level placement The background-subtracted coincidence spectra were used to determine or verify the placement of yrays in the level scheme. The low-lying excited levels below approximately 1.3 MeV are generally accepted as complete since the level structure has been studied and published many times. The high efficiency, improved resolution, and the clarity gained from Compton suppression make it easier to detect low intensity transitions not before detected. Previous investigations used one or two detectors, the 8m array has 20. Most earlier publications have used a dedicated gate, meaning that each coincidence spectrum required a separate experiment. The data recording format of the 8it allows a coincidence gate to be placed on any channel, after the experiment is completed. This depth and breadth of coincidence data allows detection and 72 placement of newly-discovered 7-rays and placement of previously unplaced (but detected) 7-rays. Since important differences in the nuclear structure description can often hinge on weakly populated levels, such information is crucial to the development of an accurate explanation of nuclei in the complex transitional region between spherical in deformed shapes. A list of all transitions in 152Gd along with all the strong contamination lines was produced. Coincidence gates were used to determine what lower levels were fed by a yray. The level sum was tabulated as the sum of the 7-ray energy the energy of the level directly fed by that transition. Groups of 7-rays with level sums within about 1.5 keV were assigned as coming from a single level. The 7-ray intensity weighted average of all the energy sums was used to calculate the level energies. An iterative process was used to check and double-check the established scheme, where level sums would be checked and possible missed feedings and alternative explanations for a particular placement were attempted. For levels with energies above 2 MeV, new levels with only one 7-ray are proposed with a lower level of confidence. 6.2.4 Transition and level results The data analysis process resulted in the confirmation of the majority of the known tray placements in '52Gd, and the establishment of at least 266 more transitions feeding or depopulating known levels or new levels. These yrays are listed ordered by initial level in Table 6-2. A listing in energy order is available in the appendix. 73 Table 6-2 Level sorted transition list. Normalized intensity is the strength of a yray with respect to all the detected yrays that depopulate a given level. Energies are in keV, LF is the fmal level for a given transition. EL J Ey LF Jf 344.3 2+ 344.3 100.00 ± 0.00 0.0 0+ 615.5 0+ 271.2 100.00 ± 5.33 344.3 2+ 0.0 0+ 615.5 755.5 4+ 930.8 2+ 1048.1 0+ 100.00 ± 5.01 344.3 2+ 175.2 0.42 ± 0.02 755.5 4+ 315.2 7.38 ± 0.37 615.5 0+ 586.7 79.55 ± 3.98 344.3 2+ 930.2 12.64 ± 0.25 0.0 0+ 117.2 5.70 ± 0.34 930.8 2+ 615.5 0+ 344.3 2+ 0.0 0+ 703.9 1048.1 1123.4 2+ 3- 1227.1 6+ 1282.4 4+ 1314.7 1318.6 1- 2+ E0 411.2 432.6 1109.4 Norm. I E0 94.30 ± 8.08 EQ 178.6 0.24 ± 0.06 930.8 2+ 353.7 0.43 ± 0.02 755.5 4+ 494.0 2.67 ± 0.14 615.5 0+ 765.2 50.82 ± 2.55 344.3 2+ 1109.3 45.85 ± 2.31 0.0 0+ 367.8 5.88 ± 0.31 755.5 4+ 779.1 94.12 ± 4.78 344.3 2+ 471.7 100.00 ± 8.15 755.5 4+ 158.4 6.44 ± 0.43 1123.4 3- 351.7 48.05 ± 2.45 930.8 2+ 527.0 45.51 ± 2.40 755.5 4+ 699.6 4.02 ± 0.22 615.5 0+ 970.5 35.47 ± 1.81 344.3 2+ 1314.7 60.51 ± 3.03 0.0 0+ 195.1 8.13 ± 0.43 1123.4 3- 208.9 0.67 ± 0.05 1109.4 2+ 270.3 9.95 ± 6.99 1048.1 0+ 387.7 7.27 ± 0.37 930.8 2+ 563.2 1.04 ± 0.06 755.5 4+ 703.3 14.96 ± 1.28 615.5 0+ 974.3 53.04 ± 2.67 344.3 2+ 1318.6 4.94 ± 0.39 0.0 0+ 74 Table 6-2 Level sorted transition list. (Continued) EL 1434.1 J 3+ 1470.7 5(-) 1475.2 0+ 1550.2 1605.8 1643.9 4+ 2+ 2- Ey Norm. I 324.7 2.93 ± 0.23 1109.4 2+ 503.6 6.07 ± 0.33 930.8 2+ 678.8 18.91 ± 1.00 755.5 4+ 1089.8 72.09 ± 4.05 344.3 2+ 100.00 ± 5.73 755.5 4+ 715.3 6+ 1681.1 0+ 1692.5 3+ 1757.1 1- 1771.7 2+ J 160.4 11.48 ± 1.03 1314.7 1- 1131 .0 88.52 ± 5.26 344.3 2+ 441.0 11.52 ± 0.86 1109.4 2+ 794.9 56.12 ± 2.99 755.5 4+ 1205.5 32.36 ± 1.99 344.3 2+ 482.5 2.08 ± 0.11 1123.4 3- 496.4 5.31 ± 0.31 1109.4 2+ 557.9 3.17 ± 0.17 1048.1 0+ 675.2 20.39 ± 1.04 930.8 2+ 850.4 0.69 ± 0.04 755.5 4+ 990.4 28.53 ± 1.45 615.5 0+ 1261.4 32.85 ± 1.67 344.3 2+ 1605.8 6.98 ± 0.35 0.0 0+ 211.6 0.30 ± 0.09 1434.1 3+ 520.4 3.32 ± 0.18 1123.4 3- 534.4 2.41 ± 0.15 1109.4 2+ 713.1 1668.2 L1 5.78 ± 0.30 930.8 2+ 1299.2 88.19 ± 4.41 344.3 2+ 912.7 100.00 ± 36.11 755.5 4+ 365.3 3.12 ± 1.26 1314.7 1- 750.5 14.37 ± 0.92 930.8 2+ 1336.8 82.50 ± 4.36 344.3 2+ 762.0 1.16 ± 0.10 930.8 2+ 937.3 15.99 ± 0.86 755.5 4+ 1348.2 82.85 ± 4.16 344.3 2+ 1412.9 100.00 ± 5.13 344.3 2+ 296.1 0.05 1475.2 0+ 456.8 11.90 ± 0.94 1314.7 1- 648.5 28.59 ± 1.57 1123.4 3- 662.7 3.21 ± 0.36 1109.4 2+ 75 Table 6-2 Level sorted transition list. (Continued) EL JI Ey Norm. I Li: 1771.7 (cont.) 723.9 6.71 ± 0.51 1048.1 0+ 841.2 9.86 ± 0.64 930.8 2+ 1016.1 14.13 ± 0.87 755.5 4+ 1427.0 25.59 ± 1.52 344.3 2+ 1808.0 1839.9 (4-) 3+ J" 337.6 9.43 ± 1.50 1470.7 5(-) 490.2 8.88 ± 0.83 1318.6 2+ 684.3 10.92 ± 0.73 1123.4 3- 877.8 9.66 ± 0.71 930.8 2+ 1052.4 61.11 ± 3.49 755.5 4+ 557.7 7.79 ± 0.48 1282.4 4+ 730.8 12.10 ± 0.91 1109.4 2+ 909.2 39.68 ± 2.13 930.8 2+ 1084.3 13.05 ± 0.74 755.5 4+ 1495.4 27.38 ± 1.52 344.3 2+ 100.00 ± 30.32 1227.1 6+ 2+ 1860.8 5+ 633.6 1862.2 2+ 753.0 1.22 ± 0.11 1109.4 738.9 12.86 ± 0.69 1123.4 3- 169.5 1.42 ± 0.09 1692.5 3+ 218.5 0.86 ± 0.06 1643.9 2- 311.7 0.56 ± 0.04 1550.2 4+ 428.0 1.14 ± 0.07 1434.1 3+ 544.0 9.07 ± 0.52 1318.6 2+ 547.4 2.49 ± 0.21 1314.7 1- 579.9 1.94 ± 0.12 1282.4 4+ 814.3 1.94 ± 0.12 1048.1 0+ 931.5 5.00 ± 0.29 930.8 2+ 1106.6 16.85 ± 0.89 755.5 4+ 1246.7 1.14 ± 0.08 615.5 0+ 1517.8 23.19 ± 1.28 344.3 2+ 1862.3 20.33 ± 1.15 0.0 0+ 1915.5 3+ 597.8 1.73 ± 0.19 1318.6 2+ 633.5 1.32 ± 0.11 1282.4 4+ 792.6 6.17 ± 0.40 1123.4 3- 806.6 4.91 ± 0.43 1109.4 2+ 1159.9 53.45 ± 2.84 755.5 4+ 1571.1 32.42 ± 1.73 344.3 2+ 76 Table 6-2 Level sorted transition list. (Continued) EL J'j Ey Norm. I Lr 1941.5 2+ 248.8 1.86 ± 0.11 1692.5 3+ 297.8 0.17 ± 0.02 1643.9 2- 335.6 1.37 ± 0.23 1605.8 2+ 391.1 0.53 ± 0.04 1550.2 4+ J' 623.0 19.39 ± 1.01 1318.6 2+ 659.2 0.48 ± 0.03 1282.4 4+ 818.1 1.76 ± 0.10 1123.4 3- 832.3 2.41 ± 0.15 1109.4 2+ 893.6 16.74 ± 0.86 1048.1 0+ 1010.8 8.83 ± 0.45 930.8 2+ 1185.9 4.70 ± 0.25 755.5 4+ 1325.9 18.43 ± 0.94 615.5 0+ 1596.9 8.22 ± 0.46 344.3 2+ 1941.3 15.12 ± 0.76 0.0 0+ 100.00 ± 8.42 930.8 2+ 1962.1 - 1031.3 1975.8 2+ 1219.4 4.26 ± 0.70 755.5 4+ 1360.3 19.57 ± 1.11 615.5 0+ 1631.5 38.23 ± 1.98 344.3 2+ 1975.8 37.94 ± 1.96 0.0 0+ 2011.8 2,3+ 2103.0 - 2121.1 4+ 2133.6 2169.8 2+ 2- 577.7 3.88 ± 0.27 1434.1 3+ 693.6 3.58 ± 0.27 1318.6 2+ 697.2 1.73 ± 0.21 1314.7 1- 902.7 18.24 ± 1.13 1109.4 2+ 1081.4 1.25 ± 0.12 930.8 2+ 1667.5 71.32 ± 3.79 344.3 2+ 100.00 ± 8.44 1314.7 1- 1282.4 4+ 755.5 4+ 2+ 788.3 839.2 3.23 ± 0.48 1365.6 96.77 ± 5.62 1789.3 79.93 ± 4.12 344.3 818.9 8.24 ± 0.80 1314.7 1- 1203.0 6.01 ± 0.41 930.8 2+ 1378.1 1.76 ± 0.16 755.5 4+ 1518.2 4.07 ± 0.28 615.5 0+ 24.18 ± 2.47 855.3 1314.7 1- 1554.8 3.17 ± 0.33 615.5 0+ 1825.4 72.65 ± 3.93 344.3 2+ 77 Table 6-2 Level sorted transition list. (Continued) EL J' Ey Norm. I LF 2193.3 - 1069.6 24.51 ± 1.96 1123.4 3- 1064.1 46.25 ± 3.67 1109.4 2+ 1262.5 27.24 ± 2.00 930.8 2+ 1092.7 15.31 ± 1.42 1109.4 2+ 1271.6 4.54 ± 0.48 930.8 2+ 1446.4 20.70 ± 1.18 755.5 4+ 2201.8 2247.0 2258.2 2265.5 2287.8 2+ 2+ - 2(+I-) - 2291.5 2300.0 2- Jf 1857.5 55.15 ± 2.88 344.3 2+ 2201.4 4.31 ± 0.26 0.0 0+ 490.8 1.97 ± 0.15 1757.1 1- 407.0 1.12 ± 0.06 1839.9 3+ 566.3 0.21 ± 0.12 1681.1 0+ 641.5 1.43 ± 0.15 1605.8 2+ 813.0 5.36 ± 0.31 1434.1 3+ 928.6 8.17 ± 0.43 1318.6 2+ 932.1 5.24 ± 0.36 1314.7 1- 1123.5 1.85 ± 0.12 1123.4 3- 1137.9 20.61 ± 1.27 1109.4 2+ 1316.2 6.59 ± 0.35 930.8 2+ 1491.5 0.56 ± 0.04 755.5 4+ 1631.5 4.08 ± 0.21 615.5 0+ 1902.6 42.31 ± 2.13 344.3 2+ 2246.4 0.49 ± 0.04 0.0 0+ 2+ 940.3 20.14 ± 1.70 1318.6 1149.1 28.62 ± 2.06 1109.4 2+ 1502.9 16.27 ± 1.05 755.5 4+ 1913.2 34.98 ± 2.19 344.3 2+ 1- 952.5 8.85 ± 0.80 1314.7 1142.2 6.92 ± 0.50 1123.4 3- 1921.1 84.23 ± 4.29 344.3 2+ 1532.4 100.00 ± 7.69 755.5 4+ 1536.0 100.00 ± 8.70 755.5 4+ (4-) 492.2 0.64 ± 0.06 1808.0 656.4 3.66 ± 0.26 1643.9 2- 865.8 4.39 ± 0.30 1434.1 3+ 985.3 6.32 ± 0.54 1314.7 1- 1176.5 1.46 ± 0.14 1123.4 3- 78 Table 6-2 Level sorted transition list. (Continued) EL 2300.0 2325.8 2327.6 J (cont.) I 2,3+ Jflf Ey Norm. I L1r 1190.5 40.49 ± 2.35 1109.4 1369.1 13.59 ± 0.79 930.8 2+ 1955.8 29.46 ± 1.61 344.3 2+ 1201.9 47.69 ± 10.59 1123.4 3- 1395.4 19.48 ± 7.12 930.8 2+ 1570.8 32.83 ± 3.31 755.5 4+ 2+ 1203.9 25.61 ± 2.20 1123.4 3- 1218.2 11.80 ± 1.34 1109.4 2+ 1983.5 62.59 ± 3.66 344.3 2+ 2330.7 3,4,5 1575.2 100.00 ± 6.12 755.5 4+ 2345.2 1,2+ 1729.7 100.00 ± 9.16 615.5 0+ 2347.8 1,2+ 2004.1 13.27 ± 2.99 344.3 2+ 2347.7 86.73 ± 4.64 0.0 0+ 2387.3 2401.8 1-2-3- 2+ 2430.7 2437.8 2+ 1072.7 3.56 ± 0.43 1314.7 1- 1263.8 50.36 ± 3.13 1123.4 3- 1457.6 3.10 ± 1.55 930.8 2+ 2043.1 42.97 ± 2.60 344.3 2+ 709.5 16.74 ± 1.09 1692.5 3+ 1083.8 3.41 ± 0.45 1318.6 2+ 1086.9 51.16 ± 4.49 1314.7 1- 1278.2 11.40 ± 0.83 1123.4 3- 1470.9 4.92 ± 0.50 930.8 2+ 1646.5 2.98 ± 0.34 755.5 4+ 1786.8 4.57 ± 0.39 615.5 0+ 2058.2 4.82 ± 0.71 344.3 2+ 2086.5 100.00 ± 12.61 344.3 2+ 756.8 3.64 ± 2.08 1681.1 0+ 1155.5 5.42 ± 0.47 1282.4 4+ 1314.5 28.09 ± 1.75 1123.4 3- 1507.0 18.61 ± 1.32 930.8 2+ 1821.5 2.03 ± 0.24 615.5 0+ 2093.5 42.22 ± 2.32 344.3 2+ 79 Table 6-2 Level sorted transition list. (Continued) EL J' Ey Norm. I Li 2495.2 1-,2 1372.0 1123.4 3- 930.8 2+ 344.3 2+ 2495.7 19.42 ± 1.22 4.68 ± 0.40 62.70 ± 3.73 13.01 ± 0.70 0.0 0+ 1564.7 2150.9 J 2500.1 3-4,5 1029.4 100.00 ± 9.55 1470.7 5(-) 2503.6 2+,34 1069.4 81.89 ± 5.64 18.11 ± 2.30 1434.1 3+ 1748.4 755.5 4+ 2168.9 87.68 ± 9.11 344.3 2+ 2513.8 12.32 ± 2.53 0.0 0+ 768.1 1757.1 1- 2180.0 3.22 ± 0.37 41.07 ± 2.71 16.47 ± 0.99 11.62 ± 0.73 0.83 ± 0.11 2.19 ± 0.20 9.69 ± 1.50 2524.4 721.8 2513.3 2524.1 1,2+ 2+ 1209.1 1400.6 1593.2 1769.3 1908.4 2529.6 3(+) 837.2 979.6 1247.2 1406.4 1599.0 2185.0 2540.3 3+ 1222.0 1417.5 1609.1 1784.7 2195.9 2544.6 (2+) 1421.1 1613.3 1790.7 1928.9 1314.7 1- 1123.4 3- 930.8 2+ 755.5 4+ 615.5 0+ 344.3 2+ 14.90 ± 0.77 0.0 0+ 0.46 ± 0.05 2.28 ± 0.20 8.69 ± 0.45 1808.0 (4-) 1692.5 3+ 1550.2 4+ 16.03 ± 0.97 12.73 ± 0.75 1282.4 4+ 1123.4 3- 30.70 ± 1.69 29.11 ± 1.75 930.8 2+ 344.3 2+ 10.90 ± 1.17 12.91 ± 1.30 3.38 ± 0.72 26.75 ± 1.68 46.06 ± 4.08 1318.6 2+ 49.99 ± 3.36 25.93 ± 1.94 10.39 ± 0.91 13.70 ± 1.29 1123.4 3- 930.8 2+ 755.5 4+ 615.5 0+ 1123.4 3- 930.8 2+ 755.5 4+ 344.3 2+ Table 6-2 Level sorted transition list. (Continued) EL J1 E'y Norm. I L1 J1 2551.5 - 1117.3 20.21 ± 1.47 1434.1 3+ 1442.1 69.38 ± 5.16 1109.4 2+ 1620.7 10.41 ± 0.98 930.8 2+ 2558.1 2+ 2580.4 - 2599.0 (2+) 2604.4 2642.0 2667.7 2687.1 2691.8 2709.7 2(-) 2,3- 1+2+ 1,2+ 1+2+ 2+ 914.6 33.69 ± 2.32 1643.9 2- 1434.9 13.50 ± 1.11 1123.4 3- 1802.5 36.05 ± 2.19 755.5 4+ 2557.7 16.76 ± 0.93 0.0 0+ 2236.1 100.00 ± 10.72 344.3 2+ 993.3 19.14 ± 2.12 1605.8 2+ 1165.0 4.31 ± 0.46 1434.1 3+ 1489.4 23.16 ± 1.79 1109.4 2+ 1668.1 7.06 ± 0.61 930.8 2+ 2254.7 37.56 ± 2.87 344.3 2+ 2598.9 8.77 ± 0.59 0.0 0+ 1- 1289.3 12.54 ± 1.75 1314.7 1481 .2 43.40 ± 2.57 1123.4 3- 2259.9 44.05 ± 3.22 344.3 2+ 1327.3 25.12 ± 2.57 1314.7 1- 1518.6 65.33 ± 3.65 1123.4 3- 1711.2 9.56 ± 0.81 930.8 2+ 975.1 24.46 ± 1.93 1692.5 3+ 1352.9 25.56 ± 2.57 1314.7 1- 1544.3 19.63 ± 1.33 1123.4 3- 1736.9 26.18 ± 1.80 930.8 2+ 2051.9 4.17 ± 0.41 615.5 0+ 1757.5 6.68 ± 1.03 930.8 2+ 2342.5 72.70 ± 3.98 344.3 2+ 2687.9 20.62 ± 1.10 0.0 0+ 1257.4 17.01 ± 1.26 1434.1 3+ 1582.1 35.25 ± 3.13 1109.4 2+ 2076.0 23.82 ± 1.56 615.5 0+ 2348.5 23.92 ± 1.65 344.3 2+ 698.0 0.33 ± 0.03 2011.8 2,3+ 953.6 2.37 ± 0.19 1757.1 1- 81 Table 6-2 Level sorted transition list. (Continued) EL 2709.7 2719.6 2729.3 2734.3 2742.4 2749.2 J (cont.) 2+ 2+ 1+ - 3+ Ey Norm. I Lf 1017.2 2.62 ± 0.17 1692.5 3+ 1066.3 0.41 ± 0.04 1643.9 2- 1275.7 0.98 ± 0.08 1434.1 3+ 1586.3 51.64 ± 2.74 1123.4 3- 1779.0 4.80 ± 0.27 930.8 2+ 2094.0 4.13 ± 0.27 615.5 0+ 2365.1 22.86 ± 1.20 344.3 2+ 2709.9 9.87 ± 0.50 0.0 0+ 454.7 0.09 ± 0.05 2265.5 2(+/-) 8045 0.81 ± 0.08 1915.5 3+ 857.9 2.43 ± 0.26 1862.2 2+ 3+ J' 1027.3 0.61 ± 0.06 1692.5 1076.2 1.96 ± 0.14 1643.9 2- 1400.7 11.13 ± 0.65 1318.6 2+ 1596.5 11.01 ± 0.60 1123.4 3- 1769.1 4.38 ± 0.26 930.8 2+ 2104.1 1.56 ± 0.11 615.5 0+ 2375.2 48.09 ± 2.51 344.3 2+ 2719.9 17.92 ± 0.92 0.0 0+ 595.8 0.55 ± 0.31 2133.6 2+ 813.9 2.33 ± 0.21 1915.5 3+ 1036.9 11.33 ± 0.71 1692.5 3+ 1085.9 11.76 ± 0.77 1643.9 2- 1410.8 24.32 ± 1.34 1318.6 2+ 1606.0 14.89 ± 0.82 1123.4 3- 1681.6 2.66 ± 0.20 1048.1 0+ 1798.5 9.91 ± 0.57 930.8 2+ 1974.0 0.37 ± 0.06 755.5 4+ 2113.6 8.36 ± 0.55 615.5 0+ 2384.3 11.90 ± 0.69 344.3 2+ 2728.9 1.62 ± 0.13 0.0 0+ 2118.6 38.93 ± 2.58 615.5 0+ 2734.4 61.07 ± 3.12 0.0 0+ 1633.5 20.19 ± 2.39 1109.4 2+ 1812.6 8.06 ± 0.96 930.8 2+ 2397.8 71.75 ± 4.66 344.3 2+ 834.2 1.37 ± 0.12 1915.5 3+ 887.5 2.82 ± 0.32 1862.2 2+ 1057.0 1.46 ± 0.11 1692.5 3+ 82 Table 6-2 Level sorted transition list. (Continued) EL 2749.2 2773.1 2776.4 2833.1 J (cont.) 2+,3 2+3,4+ 1,2+ Ey Norm. I LF Jg 1430.9 5.00 ± 0.29 1318.6 2+ 1640.1 3.21 ± 0.28 1109.4 2+ 1993.8 5.99 ± 0.34 755.5 4+ 2404.8 80.15 ± 4.17 344.3 2+ 3+ 857.5 21.55 ± 1.64 1915.5 1128.9 15.09 ± 1.27 1643.9 2- 1338.4 7.33 ± 0.72 1434.1 3+ 1454.2 9.91 ± 0.73 1318.6 2+ 1663.4 10.50 ± 1.45 1109.4 2+ 1841.8 11.97 ± 1.03 930.8 2+ 2018.1 9.85 ± 0.79 755.5 4+ 2429.9 13.81 ± 2.39 344.3 2+ 1845.2 61.88 ± 10.15 930.8 2+ 2021.4 38.12 ± 7.57 755.5 4+ 2488.8 88.46 ± 7.62 344.3 2+ 2833.5 11.54 ± 1.03 0.0 0+ 100.00 ± 13.81 1048.1 0+ 1- 2853.3 1,2+ 1805.2 2862.6 23- 1548.0 8.63 ± 0.85 1314.7 1739.5 24.36 ± 1.40 1123.4 3- 1932.2 1.43 ± 0.28 930.8 2+ 2518.2 65.58 ± 4.10 344.3 2+ 634.0 0.10 ± 0.03 2247.0 2+ 747.4 0.37 ± 0.21 2133.6 2+ 869.1 0.50 ± 0.05 2011.8 2,3+ 2880.9 2+ 965.6 3.58 ± 0.27 1915.5 3+ 1188.2 1.83 ± 0.14 1692.5 3+ 1237.3 0.78 ± 0.07 1643.9 2- 1275.2 3.86 ± 0.41 1605.8 2+ 1446.7 10.58 ± 0.62 1434.1 3+ 1562.5 3.23 ± 0.22 1318.6 2+ 1566.2 4.85 ± 0.36 1314.7 1- 1757.5 34.07 ± 1.85 1123.4 3- 1771.5 16.23 ± 0.99 1109.4 2+ 1950.1 0.61 ± 0.10 930.8 2+ 2265.1 3.68 ± 0.23 615.5 0+ 2536.3 15.75 ± 0.96 344.3 2+ 83 Table 6-2 Level sorted transition list. (Continued) jfl1 Ey 2+ 1191.7 6.22 ± 0.77 1692.5 3+ 1954.0 5.74 ± 1.09 930.8 2+ 2128.7 12.03 ± 0.86 755.5 4+ 2882.5 76.01 ± 3.87 0.0 0+ 2895.4 2551.1 100.00 ± 8.94 344.3 2+ 2901.9 1792.5 89.67 ± 6.29 1109.4 2+ 1970.8 10.33 ± 1.66 930.8 2+ EL 2882.9 2914.2 2919.9 2923.8 2928.1 2932.6 2946.7 2+ 23- 1,2+ 2+ 2+ - Norm. I Lr J 1364.2 8.20 ± 0.66 1550.2 4+ 2158.8 14.47 ± 0.87 755.5 4+ 2298.8 2.87 ± 0.21 615.5 0+ 2569.9 71.76 ± 3.79 344.3 2+ 2915.1 2.70 ± 0.16 0.0 0+ 1486.3 7.98 ± 0.74 1434.1 3+ 1605.7 6.82 ± 1.11 1314.7 1- 1797.0 36.27 ± 2.15 1123.4 3- 1810.5 11.39 ± 1.17 1109.4 2+ 2575.1 37.53 ± 3.32 344.3 2+ 2306.5 3.00 ± 0.53 615.5 0+ 2579.5 97.00 ± 9.70 344.3 2+ 1013.0 5.67 ± 0.47 1915.5 3+ 1171.9 10.99 ± 0.59 1757.1 1- 1235.5 8.91 ± 0.71 1692.5 3+ 1284.5 15.44 ± 1.09 1643.9 2- 1818.7 10.44 ± 0.81 1109.4 2+ 1996.0 0.87 ± 0.17 930.8 2+ 2172.1 6.77 ± 0.45 755.5 4+ 2313.0 0.30 ± 0.11 615.5 0+ 2583.9 32.27 ± 2.43 344.3 2+ 2927.6 8.35 ± 0.43 0.0 0+ 1809.5 15.00 ± 0.88 1123.4 3- 2177.0 5.24 ± 0.37 755.5 4+ 2317.5 1.94 ± 0.18 615.5 0+ 2588.2 77.82 ± 4.03 344.3 2+ 1836.0 0.13 ± 0.02 1109.4 2+ 2015.3 8.43 ± 0.68 930.8 2+ 2602.5 88.45 ± 5.32 344.3 2+ 2949.3 3.00 ± 0.25 84 Table 6-2 Level sorted transition list. (Continued) EL 2964.1 2981.5 2999.8 3006.5 3009.4 J 3(+) 24,3,4+ 2+ (3-) (2+) Ey Norm. I L, J' 1048.7 4.79 ± 0.43 1915.5 3+ 1414.3 6.07 ± 0.56 1550.2 4+ 1530.3 1.29 ± 0.15 1434.1 3+ 1646.1 5.87 ± 0.51 1318.6 2+ 1682.3 1.88 ± 0.19 1282.4 4+ 1841.0 9.20 ± 0.56 1123.4 3- 2033.9 24.51 ± 1.38 930.8 2+ 2209.1 2.10 ± 0.17 755.5 4+ 2619.1 44.28 ± 2.28 344.3 2+ 2050.9 31.83 ± 2.44 930.8 2+ 2225.9 29.85 ± 2.08 755.5 4+ 2637.2 38.32 ± 3.09 344.3 2+ 830.0 0.74 ± 0.44 2169.8 2- 1394.1 12.57 ± 1.45 1605.8 2+ 1- 1684.8 4.42 ± 0.87 1314.7 1876.4 3.85 ± 0.38 1123.4 3- 1890.4 6.59 ± 0.84 1109.4 2+ 2069.1 26.34 ± 1.55 930.8 2+ 2655.1 38.81 ± 3.30 344.3 2+ 3001.2 6.68 ± 0.45 0.0 0+ 837.4 1.39 ± 0.81 2169.8 2- 1090.9 5.34 ± 0.54 1915.5 3+ (4-) 1199.4 2.40 ± 0.26 1808.0 1690.2 7.04 ± 1.18 1314.7 1- 1897.1 6.60 ± 0.93 1109.4 2+ 2075.5 9.12 ± 1.31 930.8 2+ 2251.2 19.55 ± 1.41 755.5 4+ 2662.3 48.56 ± 6.17 344.3 2+ 1168.3 8.96 ± 2.80 1839.9 3+ 1253.1 5.03 ± 0.49 1757.1 1- 1364.1 1.00 ± 1.14 1643.9 2- 1690.6 7.33 ± 0.92 1318.6 2+ 1694.5 4.40 ± 0.84 1314.7 1- 1886.4 9.37 ± 0.74 1123.4 3- 2078.8 20.16 ± 1.48 930.8 2+ 2665.0 41.52 ± 8.97 344.3 2+ 3008.4 2.22 ± 0.15 0.0 0+ Table 6-2 Level sorted transition list. (Continued) EL 3012.1 3025.3 3042.3 j1C1 Ey 2+,3,4+ 681.6 2+3,4+ (2+) 3066.5 3080.3 3085.3 3088.3 3098.9 3106.6 1+2,3- 2+,3 2+3,4+ 1,2+ (2+) 2+,3+ 2+ Lr 2330.7 J 3,4,5 1901.9 15.87 ± 1.93 1109.4 2+ 2256.6 8.99 ± 0.78 755.5 4+ 2668.0 75.14 ± 9.30 344.3 2+ 1916.1 14.83 ± 1.94 1109.4 2+ 2270.0 4.31 ± 0.60 755.5 4+ 2681.0 80.87 ± 8.97 344.3 2+ 1126.9 5.55 ± 0.47 1915.5 3+ 1437.1 11.03 ± 1.26 1605.8 2+ 1727.4 17.61 ± 2.24 1314.7 1- 1933.2 8.77 ± 0.98 1109.4 2+ 3.52 ± 0.70 930.8 2+ 2697.8 53.52 ± 4.11 344.3 2+ 1613.5 15.31 ± 1.29 1434.1 3+ 1732.3 19.92 ± 3.23 1314.7 1- 2702.8 64.76 ± 5.09 344.3 2+ 2111.7 3047.1 Norm. I <1.0 1307.8 0.80 ± 0.28 1757.1 1- 2311.5 10.43 ± 0.82 755.5 4+ 2722.2 88.77 ± 7.00 344.3 2+ 1164.1 8.72 ± 1.49 1915.5 3+ 1646.3 17.92 ± 1.49 1434.1 3+ 1761.7 32.44 ± 2.98 1318.6 2+ 1956.8 10.48 ± 1.03 1123.4 3- 2150.2 15.70 ± 1.25 930.8 2+ 2324.4 14.73 ± 1.32 755.5 4+ 2740.8 54.59 ± 23.27 344.3 2+ 3085.7 45.41 ± 7.33 0.0 0+ 1965.5 13.73 ± 1.28 1123.4 3- 2334.0 4.83 ± 0.58 755.5 4+ 2743.9 76.64 ± 10.68 344.3 2+ 3088.5 4.79 ± 1.65 0.0 0+ 2168.6 22.96 ± 1.61 930.8 2+ 2754.5 77.04 ± 9.37 344.3 2+ 2350.0 30.39 ± 2.90 755.5 4+ 3107.1 69.61 ± 4.09 0.0 0+ Table 6-2 Level sorted transition list. (Continued) EL Ji Ey Norm. I Lir Jf 3112.5 1.2+ 2181.7 23.34 ± 2.73 930.8 2+ 2497.0 28.29 ± 4.51 615.5 0+ 2768.3 48.37 ± 6.02 344.3 2+ 3122.6 2+3,4+ 3132.4 3134.6 3139.8 3143.8 3153.2 2+ 2+ 2+, 3,4+ 2+3,4+ 3164.8 3182.5 3189.7 2+3,4+ - 2367.5 14.86 ± 1.86 755.5 4+ 2778.2 85.14 ± 10.82 344.3 2+ 2201.8 32.26 ± 3.12 930.8 2+ 2787.9 67.74 ± 9.26 344.3 2+ 755.5 4+ 0.0 0+ 2378.7 36.99± 13.28 3134.9 63.01 ± 6.15 1331.2 2.18 ± 0.26 1808.0 (4-) 2092.7 4.67 ± 0.53 1048.1 0+ 2208.5 9.34 ± 0.84 930.8 2+ 2382.4 11.20 ± 1.18 755.5 4+ 2525.1 15.02 ± 2.36 615.5 0+ 2795.5 45.72 ± 5.87 344.3 2+ 3140.6 11.87 ± 0.66 0.0 0+ 2213.2 13.92 ± 1.69 930.8 2+ 2388.8 26.74 ± 2.41 755.5 4+ 2799.2 59.34 ± 12.48 344.3 2+ 1347.1 5.36 ± 0.68 1808.0 (4-) 1870.9 10.37 ± 1.01 1282.4 4+ 2043.8 20.27 ± 2.41 1109.4 2+ 2223.4 5.05 ± 0.71 930.8 2+ 2397.2 15.70 ± 1.38 755.5 4+ 2808.8 43.26 ± 5.23 344.3 2+ 2233.4 15.42 ± 2.47 930.8 2+ 2820.6 84.58 ± 10.58 344.3 2+ 2059.2 11.74 ± 1.15 1123.4 3- 2251 .6 13.67 ± 2.33 930.8 2+ 2426.9 22.02 ± 2.12 755.5 4+ 2838.2 52.57 ± 6.62 344.3 2+ 1875.1 42.95 ± 6.64 1314.7 1- 2259.6 30.13 ± 4.40 930.8 2+ 2844.6 26.92 ± 4.65 344.3 2+ L 87 Table 6-2 Level sorted transition list. (Continued) EL Ji 3205.8 2+ 3212.9 3226.3 3233.0 3236.5 3250.9 3265.5 3269.9 3285.2 1+,2+ 2+3,4+ 2+3- 2+ 2+3,4+ 1-,2,3- 1,2+ 1-,2 Ey Norm. I Jflf Li: 1772.1 13.19 ± 10.53 1434.1 3+ 2275.4 8.85 ± 1.33 930.8 2+ 2449.9 6.00 ± 0.73 755.5 4+ 2861.1 47.31 ± 3.22 344.3 2+ 3206.2 24.64 ± 1.36 0.0 0+ 1521.2 13.63 ± 1.51 1692.5 3+ 1894.3 14.10 ± 1.11 1318.6 2+ 1896.9 9.49 ± 1.59 1314.7 1- 2102.8 11.53 ± 1.51 1109.4 2+ 2281.3 10.98 ± 1.44 930.8 2+ 2596.9 12.41 ± 1.94 615.5 0+ 2869.3 27.85 ± 1.97 344.3 2+ 2471.9 9.66 ± 1.40 755.5 4+ 2882.0 90.34 ± 7.69 344.3 2+ 1918.0 28.44 ± 3.67 1314.7 1- 2108.4 13.92 ± 1.70 1123.4 3- 2479.0 18.11 ± 2.73 755.5 4+ 2888.8 39.54 ± 4.54 344.3 2+ 1544.3 6.08 ± 0.74 1692.5 3+ 2128.2 10.42 ± 1.34 1109.4 2+ 2306.0 19.19 ± 2.39 930.8 2+ 2482.2 5.00 ± 1.08 755.5 4+ 2892.7 28.23 ± 2.54 344.3 2+ 3235.3 31.06 ± 3.38 0.0 0+ 2127.3 9.09 ± 1.09 1123.4 3- 2320.1 4.64 ± 0.96 930.8 2+ 2495.4 31.65 ± 3.33 755.5 4+ 2906.7 54.62 ± 3.80 344.3 2+ 1- 1951.5 27.63 ± 4.50 1314.7 2140.3 20.24 ± 2.42 1123.4 3- 2335.0 18.66 ± 2.85 930.8 2+ 2921.6 33.47 ± 3.59 344.3 2+ 2655.0 42.47 ± 3.39 615.5 0+ 3269.6 57.53 ± 4.44 0.0 0+ 1344.0 5.96 ± 0.54 1941.5 2+ 1528.9 2.24 ± 0.35 1757.1 1- 1970.4 13.72 ± 1.44 1314.7 1- 2161.7 10.62 ± 0.78 1123.4 3- 88 Table 6-2 Level sorted transition list. (Continued) EL J' Ey Norm. I LF J 3285.2 (cont.) 2176.0 5.23 ± 0.70 1109.4 2+ 2354.3 7.16 ± 0.92 930.8 2+ 2940.9 55.07 ± 3.62 344.3 2+ 2181.9 30.90 ± 2.65 1123.4 3- 2961.0 69.10 ± 8.87 344.3 2+ 3305.3 3309.7 3314.7 3325.2 - 2+3,4+ - 2+ 1021.6 5438 ± 3.07 2287.8 - 2554.9 19.72 ± 2.20 755.5 4+ 2965.7 25.91 ± 5.02 3443 2+ 2190.9 65.98 ± 5.88 1123.4 3- 2971 .2 34.02 ± 7.27 344.3 2+ 2012.2 13.24 ± 4.24 1314.7 1- 2570.8 3.24 ± 0.39 755.5 4+ 2710.7 7.55 ± 0.59 615.5 0+ 2980.5 51.58 ± 9.17 344.3 2+ 3324.9 24.38 ± 1.41 0.0 0+ 0+ 3329.0 1,2+ 3329.0 100.00 ± 7.94 0.0 3335.3 2+3,4+ 1642.4 23.84 ± 2.96 1692.5 3+ 1785.2 23.98 ± 3.04 1550.2 4+ 3340.8 (2+) 2211.7 25.43 ± 3.31 1123.4 3- 2405.0 26.75 ± 4.48 930.8 2+ 1424.6 5.60 ± 1.00 1915.5 3+ 2021.9 2.58 ± 0.40 1318.6 2+ 2217.4 26.95 ± 1.86 1123.4 3- 2585.2 15.97 ± 1.26 755.5 4+ 2995.2 46.75 ± 4.30 344.3 2+ 3338.4 2.14 ± 0.15 0.0 0+ 930.8 2+ 3350.9 - 2420.1 100.00 ± 20.63 3359.3 1-23- 2044.2 28.63 ± 5.45 1314.7 1- 2236.2 13.46 ± 1.90 1123.4 3- 2428.5 15.50 ± 2.73 930.8 2+ 3015.3 42.41 ± 4.23 344.3 2+ 2436.3 16.29 ± 2.91 930.8 2+ 3023.1 83.71 ± 15.77 344.3 2+ 3367.3 - Table 6-2 Level sorted transition list. (Continued) LF Jf 0.0 0+ EL J"1 E'y 3381.2 1,2+ 3381.2 100.00 ± 7.02 3386.4 2+2,4+ 2262.4 20.24 ± 2.11 1123.4 3- 2629.7 12.30 ± 1.17 755.5 4+ 3042.5 67.46 ± 6.01 344.3 2+ 3+ 3400.9 3413.1 3439.2 3450.0 3484.1 3499.6 3502.6 3508.9 2+,3 1,2+ 2+,3,4+ 2+,3,4 2+3,4+ 2+,3- - (2+) 3518.8 3534.9 2+ Norm. I 1484.5 4.44 ± 0.60 1915.5 1645.2 13.39 ± 1.56 1757.1 1- 1758.2 11.71 ± 1.27 1643.9 2- 2276.7 14.89 ± 1.45 1123.4 3- 2644.5 16.24 ± 1.33 755.5 4+ 3056.6 39.33 ± 3.74 344.3 2+ 3068.7 81.05 ± 9.39 344.3 2+ 3413.4 18.95 ± 1.47 0.0 0+ 2684.1 15.90 ± 2.62 755.5 4+ 3094.8 84.10 ± 4.98 344.3 2+ 2327.2 31.93 ± 5.90 1123.4 3- 2694.3 68.07 ± 7.56 755.5 4+ 2360.3 31.06 ± 3.07 1123.4 3- 2728.9 14.19 ± 1.66 755.5 4+ 3139.9 54.75 ± 10.68 344.3 2+ 3+ 1807.1 11.19 ± 1.23 1692.5 2184.8 28.60 ± 3.80 1314.7 1- 2376.3 37.69 ± 3.58 1123.4 3- 2744.1 22.53 ± 2.28 755.5 4+ 2572.2 14.09 ± 1.19 930.8 2+ 3158.3 85.91 ± 16.46 344.3 2+ 2751.7 4.29 ± 0.46 755.5 4+ 3164.7 95.71 ± 16.19 344.3 2+ 3174.5 100.00 ± 17.03 344.3 2+ 2220.9 13.85 ± 2.23 1314.7 1- 2411.9 17.23 ± 1.75 1123.4 3- 2426.0 14.57 ± 2.77 1109.4 2+ 2603.8 12.22 ± 1.63 930.8 2+ Table 6-2 Level sorted transition list. (Continued) EL E'y 3539.0 3551.2 3567.8 2+,3,4+ 2+3,4+ 3572.9 6.3 Norm. I LF J 2779.8 3.20 ± 0.45 755.5 4+ 3190.0 37.45 ± 7.47 344.3 2+ 3535.9 1.48 ± 0.17 0.0 0+ 2608.0 43.26 ± 10.58 930.8 2+ 3194.9 56.74 ± 25.90 344.3 2+ 2440.9 31.28 ± 6.84 1109.4 2+ 2619.3 17.85 ± 3.00 930.8 2+ 2796.7 50.87 ± 4.11 755.5 4+ 2635.9 5.52 ± 1.04 930.8 2+ 2811.9 5.83 ± 0.64 755.5 4+ 3223.6 88.65 ± 16.43 344.3 2+ 2462.7 19.68 ± 3.94 1109.4 2+ 3228.8 80.32 ± 15.82 344.3 2+ 3574.6 1,2+ 3574.6 100.00 ± 12.49 0.0 0+ 3589.4 - 3245.1 100.00 ± 27.83 344.3 2+ 3596.1 - 3251.8 100.00 ± 22.88 344.3 2+ 3620.9 3276.6 100.00 ± 20.01 344.3 2+ 3628.1 3283.9 100.00 ± 20.34 344.3 2+ 3655.7 3311.5 100.00 ± 39.03 344.3 2+ 3703.4 2772.5 100.00 ± 21.92 930.8 2+ 3709.4 3365.1 100.00 ± 23.05 344.3 2+ Comparison to previous results 6.3.1 New levels 54 new levels have been established by this study. Eighteen of those new levels above 1.9 MeV have only one transition and thus have low confidence. Table 6-3 shows a comparison of the levels in this experiment and those published in ;!JI Adams's recent35 paper and in the 6.3.2 TORI68 New transitions The Adam et al. data is the most recently published, but it has not been combined with the Nuclear Data Sheets (NDS). Furthermore, some of the methods used to assign transitions by Adam et al. are suspect. The Table of Radioactive Isotopes (TORI) based on the NDS has better reviewed data though it lacks the depth of the more recent data. Both the Adam et al. data and the NDS data are compared to the data from this experiment in Table 6-4. In both cases the quality of coincidence data has led to vast improvements in the power to place y-rays. The improvements to the TORI68 data are primarily due to increased detector resolution and higher statistics. Many of the differences in Adam's data are due to the method of placing transitions by energy sums alone. All of the placements in the present study were done by coincidence, which has a higher level of confidence. There are 306 transitions that are not published in the Adam et Adam or TORI data. al. study and 266 that are not published in either the 92 Table 6-3 Comparison of published levels to those proposed in this work. "A" is for Adam ez' al. and "T" is for data from the Table of Radioactive Isotopes (TORI). EL Spin EL(A) Spin (A) I 1109.4 0+ 2+ 0+ 4+ 2+ 0+ 2+ 1123.4 0.0 0 EL(T) Spin (1) 1109.19 0+ 2+ 0+ 4+ 2+ 0+ 2+ 1109.17 0+ 2+ 0+ 4+ 2+ 0+ 2+ 3- 1123.18 3- 1123.19 3- 1227.1 6+ 1227.37 1282.4 4+ 1282.27 6+ 2+ 4+ 1282.26 4+ 1314.7 1- 1314.64 1- 1314.65 1- 1318.6 1318.35 2+ 3+ 1470.7 5(-) 1470.61 2+ 3+ 2+ 1318.42 1434.1 2+ 3+ 1475.2 0+ 1550.2 4+ 2+ 1550.15 2+,3,4+ 1550.21 1605.58 2+ 1605.6 4+ 2+ 1643.9 2- 1643.43 2- 1643.41 2- 1668.2 6+ 0+ 3+ 1680.76 1692.41 3+ 1771.57 (2+,3-) 1807.66 4+ 1839.62 (2+) 1862.05 2+ 1862.06 2+ 2+ 2+ 1915.19 4+,5,6+ 1915.42 (3-,4+) 1915.69 2+,3,4+ 1941.16 2+ 1941.16 2+ 344.3 615.5 755.5 930.8 1048.1 344.28 615.37 755.4 930.55 1047.77 1274.25 1434.02 0 344.28 615.4 755.4 930.55 1047.85 1434.02 1533.91 1605.8 1681.1 1692.5 1692.42 1734.44 1757.1 1- 1755.76 1-,2-,3 1771.7 2+ 1771.56 2+ 2+ 1785.24 1808.0 (4-) 1807.53 1808.95 1839.9 1860.8 1862.2 1915.5 3+ 5+ 2+ 3+ 1941.5 2+ 1962.1 -- 1839.7 1861.9 1975.8 2+ 1975.67 1+,2+ 1975.67 1,2+ 2011.8 2,3+ 2011.65 1+,2+,3 2011.63 (3)+ 2103.0 -- 2201.79 3+ 2121.1 4+ 2+ 2133.6 2120.96 2+,3,4+ 2133.39 1+,2+ 93 Table 6-3 Comparison of published levels to those proposed in this work. (Continued) EL 2169.8 Spin 2- EL(A) 2169.58 Spin (A) EL(T) Spin (1) 1,2+ 2193.3 -- 2201.8 2201.73 2247.0 2+ 2+ 2246.77 2+ 2+ 2258.2 -- 2258.14 2+,3,4+ 2265.5 2(+/-) 2264.83 1-,2,3- 2265.28 1+,2+,3 2246.83 3+ 2265.19 (1+,2+,3+) 2267.71 2287.8 2291.5 -- 2300.0 2- 2299.64 2325.8 I 2325.82 -- 2327.6 2,3+ 2330.7 2345.2 3,4,5 2330.7 2+ 2299.66 3- 2462.77 (2+) 2+,3,4+ 1,2+ 2347.8 1,2+ 2387.3 1-,2-3- 2386.95 1-,2,3- 2401.8 2+ 2401.49 1+,2,3- 2437.44 1+2+ 2430.7 -- 2437.8 2+ 2447.82 2495.2 1-,2 2500.1 3-,4,5 2503.6 2+,3,4+ 2513.3 1,2+ 2513.9 1+,2+ 2524.1 2+ 2523.8 2+ 2529.6 2540.3 2544.6 2551.5 3(+) 2529.39 3+ 2540.45 -- 2551.12 2558.1 2+ 2557.84 2+ 2580.4 -- 2599.0 (2+) 2598.78 1+2+ 2604.4 2642.0 2(-) 1-2,3- 2,3- 2604.33 2641.56 2667.7 1+2+ 2667.54 1- 2687.1 1,2+ 2686.85 li-,2i-,3 2691.8 1+,2+ 2709.7 2+ 2+ 2709.42 2+ 2719.67 2+ 2+ 2709.32 2719.6 2719.73 (2+) 2729.3 2+ 2729.17 2+ 2729.22 2+ (2+) 2495.17 1+,2+,3 2495.3 1+ 2523.72 2+ 2529.39 (3+) 2599.28 (2+) 2687.1 (2+) 2+,3+ 2544 94 Table 6-3 Comparison of published levels to those proposed in this work. (Continued) EL Spin EL(A) 2734.3 2742.4 1+ 2734.04 -- 2744.05 2749.2 3+ 2773.1 2+,3 2776.4 2+,3,4+ 2833.1 1,2+ 2853.3 1,2+ 2862.6 2,3- 2749.2 2772.36 Spin (A) Spin (T) 1- 2+,3+ 2749.21 (2+) 2+ 2862.64 2869.76 EL(T) 1+ 2862.6 3+ 1,2+ 2+ 2+ 2880.65 1+,2+ 2880.61 1- 2901.9 2914.2 2+ 2913.98 2+ 2,3- 2914.15 2920.08 2+ 2919.9 2923.8 1,2+ 2928.1 2+ 2927.85 24-,3+ 2928.8 3+ 2+ 2932.6 (2+3+) 2-,3- 2964.2 2+ 3007.2 3- 3024.3 1+,2+ 2880.9 2882.9 2895.4 2928.68 2+ 2932.66 2964.1 3(+) 2964.33 2981.5 2+,3,4+ 2981.38 2999.8 2+ 2999.52 3006.5 3009.4 (3-) 3006.71 2+ (2+) 3009.16 3012.06 2-,3- 2932.6 2946.7 2+,3,4+ 2989.02 3012.1 2+,3,4+ 3025.3 2+,3,4+ 3042.3 3047.1 (2+) 1+,2,3- 3066.5 2+,3 3080.3 2+,3,4+ 3085.3 3088.3 3098.9 3106.6 1,2+ (2+) 2+,3+ 2+ 3042.3 1+,2+ 2+,3+ 0+,1+,2 2+ 3085.2 2+ 3067.4 3074.86 3079.64 3+,4+ 3090.4 3098.99 3105.49 2+ 3112.5 1.2+ 3110.9 1+,(2+) 3122.6 2+,3,4+ 3112.5 1+,2+ 3132.4 -- 3134.6 2+ 2+ 3139.8 3042.16 3099.36 3106.4 (+) 1,2+ 95 Table 6-3 Comparison of published levels to those proposed in this work. (Continued) EL Spin 3143.8 2+, 3,4+ 3153.2 3164.8 3182.5 3189.7 3205.8 24,3,4+ 3212.9 3226.3 3233.0 3236.5 3250.9 3259.4 3265.5 3269.9 3285.2 3305.3 3309.7 3314.7 3325.2 3329.0 3335.3 3340.8 3350.9 3359.3 3367.3 3381.2 3386.4 3400.9 3413.1 3439.2 3450.0 3484.1 3499.6 3502.6 3508.9 3518.8 3534.9 3539.0 ( Spin (A) EL(A) 3140.17 1+,2+ 3143.96 3152.98 24,3,4+ -- 24,3,4+ -2+ 1+,2+ 24,3,4+ 2+,32+ 2+,3,4+ -1-,2,31,2+ 1-,2 -2+,3,4+ -2+ 1,2+ 2+,3,4+ (2+) -1-,2,3-1,2+ 2+,2,4+ 2+,3 1,2+ 24,3,4+ 24,3,4 2+,3,4+ 2+,3-(2+) -2+ -- I Spin (T) EL(T) 3140 1- 3159.6 3165.1 1,2+ 1,2+ 3189.5 3191.3 3205.4 1-2+ 3250.9 (1)- 3284.9 (1+,2+) 3309.7 1,2+ 3324.2 3328.8 3337.8 (1,2) 1,2+ 1- 3214.23 3232.05 3236.92 3285.12 24,3,4+ 2+ 3340.6 3- 3358.26 2+ 1,2+ (1,2+) 3357.98 (2+) 3393.27 2+ 3411.5 3433.2 (2)+ 2+ 3478.9 1,2+ Table 6-3 Comparison of published levels to those proposed in this work. (Continued) EL Spin 3551.2 2+,3,4+ 3567.8 2+,3,4+ EL(T) Spin (T) 3572.9 3574.6 1,2+ 3589.4 -- 3596.1 -- 3620.9 - 3628.1 -- 3655.7 3703.4 3709.4 3573.2 (1,2+) 97 Table 6-4 Transition comparison. The leftmost data is from this study, the center data is from Adam et al., and the right is from the Table of Radioactive Isotopes (TORI) data. Since the Adam et al. intensities are normalized by level, the data from this experiment have been normalized by level. The intensities for the TORI data are normalized to the 344 keV yray. The appendix contains a listing of the values from this experiment normalized in the same way as the TORI data. Three transitions are purely electric monopole, they are listed as "E0". The intensity of these transitions was not measured in this experiment. Some Adam et al. measurements show error of 0.00, or are blank. This indicates that the provided intensity is a lower limit. EL This Experiment E7 I out of level Ey (A) Adam et al. I out of level TORI Ey(T) I 344.3 344.3 100.00 ± 0.00 344.279 100 ± 2.5 344.28 1000 615.5 271.2 615.5 100.00 ± 5.33 271.09 615.6 99.97 ± 2.2 0.03 ± 0.00 271.08 615.6 132 19.8 755.5 411.2 100.00 ± 5.01 411.1165 100 ± 2.47 411.08 63 930.8 175.2 315.2 586.7 930.2 0.02 0.37 3.98 0.25 175.14 315.16 586.27 930.58 0.21 ± 0.02 175 7.04 ± 0.15 80.04 ± 1.65 12.72 ± 0.44 315.2 586.29 930.7 5.70 ± 0.34 117.25 432.5 703.494 1047.9 3.19 ± 0.09 0.12 ± 0.00 96.17 ± 2.84 0.53 ± 0.00 117.4 432.5 703.34 1047.9 0.22 0.52 2.59 50.14 46.54 2.1 ± 1.04 494 764.88 1109.2 367.8 778.86 5.5 89 1048.1 1109.4 1123.4 1227.1 117.2 432.6 703.9 1048.1 EU 0.42 7.38 79.55 12.64 ± ± ± ± EU 94.30 ± 8.08 EU 178.6 353.7 494.0 765.2 1109.3 0.24 0.43 2.67 50.82 45.85 ± 2.31 178.58 353.78 493.81 764.89 1109.2 367.8 779.1 5.88 ± 0.31 94.12 ± 4.78 367.8 778.9045 5.93 ± 0.15 94.07 ± 1.94 471.7 100.00 ± 8.15 471.98 100 ± 4.14 658.83 100 ± 6.7 ± 0.06 ± 0.02 0.14 ± 2.55 ± 1274.25 1282.4 1314.7 0.69 13.3 145 28 0.8 8 26 0.35 ± 0.02 ± 0.02 ± 0.07 ± 1.16 45 41 158.4 351.7 527.0 6.44 ± 0.43 48.05 ± 2.45 45.51 ± 2.40 159.16 351.73 526.85 1.85 ± 0.2 46.06 ± 1.13 351.7 526.9 3.6 52.1 ± 1.13 699.6 970.5 1314.7 4.02 ± 0.22 35.47 ± 1.81 60.51 ± 3.03 699.25 970.32 1314.635 3.97 ± 0.28 37.45 ± 0.79 58.58 ± 2.2 699 970.4 1314.7 1.6 14.3 4 22 Table 6-4 Transition comparison. (Continued) EL Ey 1 out of level 1318.6 195.1 8.13 ± 0.43 195.17 7.95 ± 0.18 195.2 6.3 208.9 0.67 ± 0.05 209.14 0.72 ± 0.03 209.3 0.4 270.3 9.95 ± 6.99 270.55 6.5 387.7 7.27 ± 0.37 387.8 7.46 ± 0.25 387.8 6.4 563.2 1.04 ± 0.06 562.98 1.34 ± 0.04 563.3 703.3 14.96 ± 1.28 702.976 17.07 ± 0.64 703.34 974.3 1434.1 1470.7 1475.2 1605.8 1643.9 I out of level Ey(T) 1.1 12.1 53.04 ± 2.67 974.05 1318.6 4.94 ± 0.39 1318.24 324.7 2.93 ± 0.23 324.9 0.15 325.3 <1.0 503.6 6.07 ± 0.33 503.43 5.25 ± 0.14 503.5 0.9 678.8 18.91 ± 1.00 678.61 18.24 ± 0.41 678.6 4.1 1089.8 72.09 ± 4.05 1089.737 1089.9 20 115.3 0.06 1.34 441 794.7 -0.4 715.3 100.00 ± 5.73 160.4 11.48 ± 1.03 1131.0 88.52 ± 5.26 1533.91 1550.2 Ey (A) 715.19 60.11 ± 1.27 974.1 5.35 ± 0.22 1318.2 3.42 ± 73.1 ± 1.5 68.8 ± 48 6 1.73 855.237 31.2 ± 6.07 603.18 100 ± 6.86 441.0 11.52 ± 0.86 441.02 13.71 ± 0.36 794.9 56.12 ± 2.99 794.73 52.54 ± 1205.5 32.36 ± 1.99 1205.83 33.75 ± 1.34 1206 3 482.5 2.08 ± 0.11 482.34 2.17 ± 0.05 496.4 5.31 ± 0.31 496.37 5.46 ± 0.12 482.3 496.4 2.1 557.9 3.17 ± 0.17 557.81 2.71 ± 0.26 557.6 1.6 675.2 20.39 ± 1.04 675.01 19.83 ± 675.1 2.2 850.4 0.69 ± 0.04 850.49 1.12 ± 990.4 28.53 ± 1.45 32.85 ± 1.67 990.19 26.69 ± 0.55 990.3 9 1261.4 1261.32 33.72 ± 0.71 1261.4 16.6 1605.8 6.98 ± 0.35 1605.584 1605.8 2.4 211.6 0.30 ± 0.09 520.4 3.32 ± 0.18 520.3 2.69 ± 0.11 520.3 534.4 2.41 ± 0.15 534.21 2.29 ± 0.06 534.1 713.1 5.78 ± 0.30 712.82 4.91 ± 0.17 713 1299.2 88.19 ± 4.41 1299.14 90.12 ± 1.94 1299.11 912.7 100.00 ± 36.11 8.31 ± 0.4 0.5 3 0.09 1.19 S I 1668.2 1.8 2 1.9 0.043 Table 6-4 Transition comparison. (Continued) EL Ey 1681.1 365.3 3.12 ± 1.26 750.5 14.37 ± 0.92 366.15 750.06 1336.8 82.50 ± 4.36 1336.54 1692.5 l out of level 762.0 1.16 ± 0.10 937.3 15.99 ± 0.86 937.04 1348.2 82.85 ± 4.16 1348.15 1734.44 1757.1 1412.9 1771.7 296.1 <0.05 456.8 11.90 ± 0.94 100.00 ± 5.13 1860.8 out of level 7.5 ± 0.76 74.61 ± 1.52 16.01 ± 0.63 83.99 ± 100 ± 5.77 1411.48 100 ± 5.88 12.06 ± 0.5 489.59 7.06 ± 0.56 648.31 30.85 ± 0.74 28.59 ± 1.57 3.21 ± 0.36 723.9 6.71 ± 0.51 723.67 5.98 ± 0.24 841.2 9.86 ± 0.64 841.1 13.38 ± 0.74 1016.1 14.13 ± 0.87 1427.0 25.59 ± 1.52 337.6 9.43 ± 1.50 490.2 8.88 ± 0.83 684.3 10.92 ± 0.73 877.8 9.66 ± 0.71 1052.4 61.11 ± 3.49 1427.32 30.66 ± 0.74 662.02 38.44 ± 4.2 854.69 61.56 ± 1052.15 100 ± 2.16 70.77 ± 2.31 557.433 12.47 ± 2.45 7.79 ± 0.48 730.8 12.10 ± 0.91 909.2 39.68 ± 2.13 909.15 1084.3 13.05 ± 0.74 1495.4 27.38 ± 1.52 1084.305 1495.44 633.6 100.00 ± 30.32 3 1348.1 -13 456.9 2 648.4 2 840.8 2 1016.4 2 1427.4 2 12.01 490.66 878.13 557.7 937 1.69 979.04 456.92 E1(T) 17.89 ± 0.99 662.7 1808.95 1839.9 I 648.5 1785.24 1808.0 Ey (A) 1052.3 29.23 ± 2.31 715.5 3 730.4 2 1.23 909.1 2 14.31 ± 3.27 1084.1 4 33.33 ± 1495.6 1.6 39.88 ± 1.23 100 Table 6-4 Transition comparison. (Continued) EL E7 I out of level 1862.2 169.5 1.42 ± 0.09 218.5 0.86 ± 0.06 311.7 0.56 ± 0.04 1.14 ± 0.07 427.85 2.04 ± 0.14 9.07 ± 0.52 543.58 19.58 ± 0.45 547.4 2.49 ± 0.21 579.9 1.94 ± 0.12 579.63 3.04 ± 0.16 738.9 12.86 ± 0.69 738.69 21.72 ± 0.58 753.0 1.22 ± 0.11 752.59 3.23 ± 0.26 814.3 1.94 ± 0.12 814.123 2.46 ± 0.45 931.5 5.00 ± 0.29 1106.6 16.85 ± 0.89 1246.7 1.14 ± 0.08 1517.8 23.19 ± 1.28 1862.3 20.33 ± 1.15 597.8 806.6 1861.94 46.53 ± 0.97 547.47 7.34 ± 0.19 1106.59 39.94± 1.19 1517.78 52.72 ± 3.95 1.73 ± 0.19 597.57 5.14 ± 0.34 1.32 ± 0.11 633.6 792.56 9.64 ± 0.61 1571.25 76.24 ± 1.53 6.17 ± 0.40 4.91 ± 0.43 1159.9 53.45 ± 2.84 1571.1 32.42 ± 1.73 E?(T) I 1.41 ± 0.07 544.0 633.5 792.6 1915.19 218.42 I out of level 428.0 1862.06 1915.5 Ey (A) 543.7 3 547.5 2 738.7 3 1106.7 7 1517.8 -0.28 1861.9 7.6 143.8 5 1160 6 1570.8 3 8.97 ± 0.34 687.62 3.52 ± 0.94 1159.82 96.48 ± 2.35 101 Table 6-4 Transition comparison. (Continued) EL Ey 1941.5 248.8 1.86 ± 0.11 248.75 1.46 ± 0.18 248.5 1.7 297.8 0.17 ± 0.02 298.06 0.16 ± 0.02 335.5 <1.0 335.6 1.37 ± 0.23 335.56 1.37 ± 0.04 391.1 0.53 ± 0.04 390.82 623.0 19.39 ± 1.01 622.79 659.2 0.48 ± 0.03 818.1 1.76 ± 0.10 817.974 2.21 ± 0.37 818.2 832.3 2.41 ± 0.15 831.94 2.63 ± 0.07 14.85 ± 0.31 1962.1 I Ey (A) out of level 893.6 16.74 ± 0.86 893.34 1010.8 8.83 ± 0.45 1010.6 1185.9 4.70 ± 0.25 1325.9 I out of level 2103.0 2121.1 0.44 1 658.8 831.9 2 2 3 893.3 10.3 1010.7 6.5 1185.73 4.96 ± 0.12 1185.6 3.7 18.43 ± 0.94 1325.86 18.23 ± 0.38 1325.8 14 1596.9 8.22 ± 0.46 1596.877 7.03 ± 0.37 1596.9 -0.28 1941.3 15.12 ± 0.76 1941.23 18.3± 0.34 1941.1 11.1 1031.3 100.00 ± 8.42 1219.4 4.26 ± 0.70 9.3 ± 113.5 1360.3 19.57 ± 1.11 1360.43 16.92 ± 0.77 1360 5 1631.5 38.23 ± 1.98 1631.39 39.84 ± 2.92 1631.5 4 1975.8 37.94 ± 1.96 1975.65 43.24 ± 0.95 1975.5 2 577.7 3.88 ± 0.27 577.57 693.6 3.58 ± 0.27 693.13 3.1 ± 0.21 694.1 2 697.2 1.73 ± 0.21 697.2 1.77 ± 0.59 902.46 16.64 ± 0.44 902.4 2 902.7 18.24 ± 1.13 1081.4 1.25 ± 0.12 1667.5 71.32 ± 3.79 788.3 839.2 1667.38 1789.3 2.03 ± 0.1 76.46 ± 1.77 100.00 ± 8.44 3.23 ± 0.48 839.6 96.77 ± 5.62 1365.69 1776.3 21698 622.8 0.19 1365.6 2133.6 I 0.17 ± 0.03 21.33 ± 1975.8 2011.8 E'y(T) 11.67 ± 2.22 75.56 ± 1.67 12.78 ± 1.67 79.93 ± 4.12 818.9 8.24 ± 0.80 1203.0 6.01 ± 0.41 1378.1 1.76 ± 0.16 151 8.2 4.07 ± 0.28 t 818.755 1.17 ± 0.47 1202.84 5.01 ± 1.4 1518.017 5.83 ± 1.17 1789.11 88 ± 2.33 8553 2418 ±247 854945 911 ± 245 1554.8 3.17 ± 0.33 1554.04 7.47 ± 0.67 1825.4 72.65 ± 3.93 1825.37 83.42 ± 1.75 1667.4 0.26 102 Table 6-4 Transition comparison. (Continued) EL Ey 2193.3 1069.6 24.51 ± 1.96 1084.1 48.25 ± 3.67 1262.5 27.24 ± 2.00 1092.7 15.31 ± 1.42 1271.6 4.54 ± 0.48 1446.4 1857.5 2201.4 2201.8 2247.0 2258.2 l out of level ET (A) I out of level Ey(T) I 1092.26 11.32 ± 0.63 20.70 ± 1.18 1446.335 27.47 ± 2.73 1446.5 55.15 ± 2.88 1857.48 57.04 ± 1857.3 -0.07 4.31 ± 0.26 2201.65 4.17 ± 0.42 407.12 0.37 ± 0.05 1.26 490.8 1.97 ± 0.15 407.0 1.12 ± 0.06 566.3 0.21 ± 0.12 641.5 1.43 ± 0.15 641.2 1.58 ± 0.04 641.3 813.0 5.36 ± 0.31 812.8 5.32 ± 0.14 812.8 3 928.6 8.17 ± 0.43 928.43 9.63 ± 0.2 928.7 7 932.09 5.17 ± 0.19 0.6 932.1 5.24 ± 0.36 1123.5 1.85 ± 0.12 1123.3 3 1137.9 20.61 ± 1.27 1137.56 22.87 ± 0.49 1137.6 -9 1316.2 1491.5 6.59 ± 0.35 0.56 ± 0.04 1316.32 5.25 ± 0.41 1316 5 1491.62 0.45 ± 0.03 1631.5 4.08 ± 0.21 1631.399 1902.6 42.31 ± 2.13 1902.492 45.09 ± 1.02 2246.4 0.49 ± 0.04 36.81 ± 1.25 4.27 ± 0.25 940.3 20.14 ± 1.70 939.84 1149.1 28.62 ± 2.06 1148.99 46.53 ± 2.08 1502.9 16.27 ± 1.05 1502.62 16.67 * 1913.2 34.98 ± 2.19 2265.5 947.08 11.66 ± 2.12 8.85 ± 0.80 950.34 26.74 ± 1142.2 6.92 ± 0.50 1141.68 1921.1 84.23 ± 4.29 1921 100 ± 2.12 2267.71 953.07 90.54 ± 2.27 1040.6 9.46 ± 1.99 2291.5 1536.0 100.00 ± 8.70 1920.9 6.6 1.18 61.6 ± 2.83 2265.28 1532.4 100.00 ± 7.69 -0.11 0.56 952.5 2287.8 1902.4 103 Table 6-4 Transition comparison. (Continued) EL Ey 2300.0 492.2 0.64 ± 0.06 656.4 3.66 ± 0.26 656.42 3.35 ± 0.15 865.8 4.39 ± 0.30 865.62 3.76 ± 0.15 l out of level Ey (A) I out of level Ey('I) 656.6 0.6 985.1 2 985.3 6.32 ± 0.54 984.9 1176.5 1.46 ± 0.14 1176.53 1190.5 40.49 ± 2.35 1190.44 37.7 ± 0.75 1190.5 0.28 1369.1 13.59 ± 0.79 1369.04 12.48 ± 0.31 1369.2 0.35 5.8 ± 0.31 2.7 ± 0.11 1544 2325.8 2327.6 2330.7 1955.8 29.46 ± 1.61 1955.36 1201.9 47.69 ± 10.59 1202.64 1395.4 19.48 ± 7.12 1570.8 32.83 ± 3.31 1203.9 25.61 ± 2.20 1218.2 11.80 ± 1.34 1983.5 62.59 ± 3.66 1575.2 100.00 ± 6.12 1575.3 1986.8 2345.2 1729.7 100.00 ± 9.16 2347.8 2004.1 13.27 ± 2.99 2347.7 86.73 ± 4.64 2387.3 2401.8 2430.7 I 34.2 ± 0.75 100 ± 21.74 92.61 ± 2.46 7.39 ± 1.48 1.59 1072.7 3.56 ± 0.43 1072.16 12.35 ± 1263.8 50.36 ± 3.13 1263.84 43.82 ± 1.59 2042.67 43.82 ± 1457.6 3.10 ± 1.55 2043.1 42.97 ± 2.60 3.19 709.5 16.74 ± 1.09 708.98 1083.8 3.41 ± 0.45 1083.141 16.42 ± 3.79 1086.9 51.16 ± 4.49 1087.12 65.38 ± 2.53 1278.2 11.40 ± 0.83 1470.9 4.92 ± 0.50 1646.5 2.98 ± 0.34 1786.8 4.57 ± 0.39 2058.2 4.82 ± 0.71 2086.5 100.00 ± 12.61 18.19 ± 0.66 1955.3 5 0.27 104 Table 6-4 Transition comparison. (Continued) EL Ey l out of level 2437.8 756.8 3.64 ± 2.08 Ey (A) I out of level E7(T) I J 1155.5 5.42 ± 0.47 1314.5 28.09 ± 1.75 1314.257 1507.0 18.61 ± 1.32 1506.9 11.78± 0.44 1821.5 2093.5 2.03 ± 0.24 2093.16 31.86 ± 2.72 42.22 ± 2.32 2437.11 1.99 ± 0.15 2103.54 100 ± 21.28 2447.82 2495.2 2500.1 2503.6 2513.3 1372.0 19.42 ± 1.22 1564.7 4.88 ± 0.40 2150.9 62.70 ± 3.73 2495.7 13.01 ± 0.70 7.55 857.1 2 1353 <1.5 1532.3 1.4 2118.5 0.8 2150.9 -0.6 2495.6 -1.7 42.42 ± 0.94 1209.1 0.06 14.42 ± 1400.6 3 1908.5 0.5 1372.04 18.01 ± 0.54 2150.85 81.99 ± 1.63 1029.4 100.00 ± 9.55 1069.4 1748.4 81.89 ± 5.64 18.11 ± 2.30 2168.9 87.68 ± 9.11 2169.16 2513.8 12.32 ± 2.53 2513.9 9.99 ± 2.53 684.12 2.53 ± 0.28 880.29 6.08 ± 0.2 2524.1 768.1 2529.6 54.36 ± 90.01 ± 25.32 3.22 ± 0.37 1209.1 41.07 ± 2.71 1209.03 1400.6 1593.2 16.47 ± 0.99 1400.617 1593.37 1769.3 0.83 ± 0.11 1908.4 2.19 ± 0.20 2180.0 2524.4 9.69 ± 1.50 2179.42 8.71 ± 0.23 2179.1 1 14.90 ± 0.77 2523.92 12.27 ± 0.28 2523.9 1.4 721.8 0.46 ± 0.05 722 1.83 ± 0.13 837.2 2.28 ± 0.20 1247.07 19.12 ± 0.55 11.62 ± 0.73 1.22 13.58 ± 0.37 979.6 8.69 ± 0.45 1247.2 16.03 ± 0.97 1247.1 2 1406.4 12.73 ± 0.75 1406.16 14.64 ± 0.37 1406.1 1.5 1420.6 2 1599.0 30.70 ± 1.69 1598.9 31.66 ± 0.73 1598.9 2185.0 29.11 ± 1.75 2185.24 32.75 ± 0.64 2185 7 3.3 / 105 Table 6-4 Transition comparison. (Continued) EL Ey 2540.3 1222.0 1417.5 10.90 ± 1.17 1221.95 11.51 ± 0.76 12.91 ± 1.30 1417.18 10.85 ± 0.55 1609.1 3.38 ± 0.72 2544.6 2551.5 2558.1 2580.4 2599.0 1 out of level Ey (A) I out of level 1784.7 26.75 ± 1.68 1785.15 2195.9 46.06 ± 4.08 2196.2 1421.1 49.99 ± 3.36 1420.76 51.13 ± 1.42 1613.3 25.93 ± 1.94 1613.53 48.87 ± 1790.7 10.39 ± 0.91 1928.9 13.70 ± 1.29 1117.3 20.21 ± 1.47 1117.15 16.86 ± 0.64 1442.1 69.38 ± 5.16 1441.91 83.14 ± 2.28 1620.7 10.41 ± 0.98 26.69 ± 1.39 50.95 ± 914.6 33.69 ± 2.32 914.35 1434.9 13.50 ± 1.11 1802.5 36.05 ± 2.19 1434.54 1802.67 38.17 ± 2211.7 0± 2557.7 16.76 ± 0.93 2236.1 100.00 ± 10.72 993.3 19.14 ± 2.12 1165.0 4.31 ± 0.46 1489.4 23.16 ± 1.79 1668.1 7.06 ± 0.61 2254.7 37.56 ± 2.87 2598.9 8.77 ± 0.59 Ey(T) 30.53 ± 1.04 1.66 0.89 16.81 ± 0.82 1.01 2557.91 14.5 ± 0.45 993.14 21.24 ± 0.86 1489.6 22.09 ± 1284.6 1983.41 2604.4 2642.0 2667.7 2254.54 0.64 1489.8 2 3 24.5 ± 0.58 32.18 ± 0.64 1289.3 12.54 ± 1.75 1289.64 18.98 ± 0.6 1481.2 43.40 ± 2.57 39.25 ± 2 2259.9 44.05 ± 3.22 1481.18 2260.05 1327.3 25.12 ± 2.57 1518.6 65.33 ± 3.65 1518.377 83.89 ± 6.23 1711.2 9.56 ± 0.81 1711.02 16.11 ± 0.53 41.77 ± 2255.2 2599.4 1.2 1372 0.7 2 I 975.1 24.46 ± 1.93 1352.9 25.56 ± 2.57 1352.98 22.32 ± 2.43 1544.3 19.63 ± 1.33 1544.29 45.9 ± 1.12 1736.9 26.18 ± 1.80 1737.03 31.78 ± 0.82 2051.9 4.17 ± 0.41 106 Table 6-4 Transition comparison. (Continued) E 2687.1 2691.8 I Ey I Loutoflevel 1757.5 2342.5 2687.9 6.68 ± 1.03 72.70 ± 3.98 20.62 ± 1.10 1257.4 17.01 ± 1.26 1582.1 35.25 ± 3.13 23.82 ± 1.56 23.92 ± 1.65 2076.0 2348.5 : EyA) 2342.57 I out of level 100± 1.97 2709.7 454.7 804.5 857.9 1027.3 1076.2 1400.7 1596.5 I 2.2 2 0.26 0.33 ± 0.03 2.37 ± 0.19 2.62 ± 0.17 0.41 ± 0.04 0.98 ± 0.08 51.64 ± 2.74 4.80 ± 0.27 4.13 ± 0.27 22.86 ± 1.20 9.87 ± 0.50 0.09 ± 0.05 0.81 ± 0.08 2.43 ± 0.26 0.61 ± 0.06 1066.23 0.66 ± 0.05 1586.22 1778.78 2094.047 2365.13 2709.47 55.81 ± 1.15 6.35 ± 0.19 4.7 ± 0.42 21.94 ± 0.54 10.55 ± 0.23 454.82 0.36 ± 0.08 1027.16 0.77 ± 0.09 1401.321 1596.487 1789.12 2104.297 2375.34 2719.61 4.13 ± 0.37 11.14± 0.83 6.6 ± 0.5 2.48 ± 0.55 56.15± 1.19 813.475 1036.74 1085.68 1258.45 1410.816 1605.982 1681.53 1798.45 1.08 ± 0.51 10.92 ± 0.25 13.65 ± 0.44 10.03 ± 0.38 1411.5 1605.8 1681.4 1797.8 2113.7 2384.94 2729.25 8.64 ± 0.19 9.21 ± 0.19 1.66 ± 0.06 2114 2384.7 2729 1275.1 1.6 1586.23 1778.6 2093.3 2365.3 2709.4 0.19 1596.9 0.25 0.26 1.3 1 6.7 3 1.96 ± 0.14 2375.2 2719.9 11.13 ± 0.65 11.01 ± 0.60 4.38 ± 0.26 1.56 ± 0.11 48.09 ± 2.51 17.92 ± 0.92 595.8 0.55 ± 0.31 813.9 1036.9 1085.9 2.33 ± 0.21 11.33 ± 0.71 11.76 ± 0.77 1410.8 1606.0 1681.6 1798.5 1974.0 2113.6 2384.3 2728.9 24.32 ± 1.34 14.89 ± 0.82 2.66 ± 0.20 9.91 ± 0.57 0.37 ± 0.06 8.36 ± 0.55 11.90 ± 0.69 1.62 ± 0.13 1789.1 2104.1 2729.3 2342.8 2687.3 180 698.0 953.6 1017.2 1066.3 1275.7 1586.3 1779.0 2094.0 2365.1 2709.9 2719.6 Ey(T) 18.38 ± 0.41 4.76 ± 0.18 20.96 ± 1.27 14.92 ± 1.91 4.17± 0.11 1789.1 2375.3 2719.82 0.15 6 788 2 1037 2 1086.3 -0.18 4.3 7 2 3 1.5 2.8 107 Table 6-4 Transition comparison. (Continued) EL Ey 2734.3 2118.6 2734.4 2742.4 Ey (A) I out of level 38.93 ± 2.58 2118.66 38.1 ± 61.07 ± 3.12 2734.06 61.9 ± 1.31 1633.5 20.19 ± 2.39 1634 8.14 ± 1.89 1812.6 8.06 ± 0.96 2397.8 71.75 ± 4.66 2744.1 91.86 ± 1.96 301.82 0.31 ± 0.09 I out of level 2749.2 834.2 1.37 ± 0.12 887.5 2.82 ± 0.32 1057.0 1.46 ± 0.11 1430.9 5.00 ± 0.29 1640.1 2773.1 3.21 ± 0.28 1.42 ± 0.05 1215.2 0.66 ± 0.07 1430.76 5.91 ± 0.24 1640.08 2853.3 0.2 5.99 ± 0.34 1993.87 2404.8 80.15 ± 4.17 2405 82.62 ± 1.6 857.5 21.55 ± 1.64 857.33 27.89 ± 1.99 1128.9 1338.4 2833.1 0.6 ± 2.73 ± 0.09 1993.8 1016.6 2776.4 I 1056.79 1475.04 5.75 ± 0.12 24.8 ± 0.66 15.09 ± 1.27 1128.65 7.33 ± 0.72 1338.5 1454.2 9.91 ± 0.73 1454.08 1663.4 10.50 ± 1.45 1663.67 14.83 ± 0.89 1841.8 11.97 ± 1.03 1841.81 9.08± 1.11 2018.1 9.85 ± 0.79 2429.9 13.81 ± 2.39 2772.44 1.77 ± 0.11 1845.2 2021.4 61.88 ± 10.15 2488.8 2833.5 88.46 ± 7.62 38.12 ± 7.57 11.54 ± 1.03 1805.2 100.00 ± 13.81 9.52 ± Ey(T) 1.11 4.27 ± 0.58 7.84 ± 0.44 1640.8 0.8 1818.5 0.8 1993.6 2405 3 22.9 108 Table 6-4 Transition comparison. (Continued) EL Ey 2862.6 1548.0 E7 (A) I out of level 8.63 ± 0.85 1547.95 17.7 ± 0.49 1739.5 24.36 ± 1.40 1739.46 33.26 ± 0.74 1739.2 3 1932.2 1.43 ± 0.28 2518.2 65.58 ± 4.10 2518.42 49.04 ± 2518.5 0.21 634.1 0.3 I out of level 2869.76 2880.9 2882.9 1.1 2254.44 100 ± 2 2525.43 0 ± 634.0 0.10 ± 0.03 747.4 0.37 ± 0.21 747.29 0.55 ± 0.04 869.1 0.50 ± 0.05 868.94 1.44 ± 0.05 965.6 3.58 ± 0.27 1188.37 1.96 ± 0.08 5.39 ± 0.14 1188.2 1.83 ± 0.14 1237.3 0.78 ± 0.07 Ey(T) I 1275.2 3.86 ± 0.41 1275.04 1446.7 10.58 ± 0.62 1446.635 8.91 ± 0.9 1446.5 2.8 1562.5 3.23 ± 0.22 1562.45 4.49 ± 0.1 1562.3 1.1 1566.2 4.85 ± 0.36 1565.97 5.55 ± 0.01 1566.2 3 1757.5 1771.5 34.07 ± 1.85 16.23 ± 0.99 1757.42 1771.43 1757.4 1771.4 11.1 1950.1 0.61 ± 0.10 35.36 ± 0.8 18.03 ± 0.38 2265.1 3.68 ± 0.23 2265.33 2536.3 15.75 ± 0.96 2536.3 13.75 ± 0.38 1191.7 6.22 ± 0.77 998.37 5.18 ± 0.28 1954.0 5.74 ± 1.09 2128.7 12.03 ± 0.86 2882.5 76.01 ± 3.87 2895.4 2551.1 100.00 ± 8.94 2901.9 1792.5 1970.8 89.67 ± 6.29 1364.2 8.20 ± 0.66 2265 1.3 2536.3 4.9 1598.9 13 10.33 ± 1.66 2914.2 2158.8 4.59 ± 0.1 4.6 14.47 ± 0.87 2158.72 27.81 ± 0.76 1983A 2 2158.6 1.3 2298.8 2.87 ± 0.21 2569.9 71.76 ± 3.79 2569.85 63.95 ± 1.52 2570 2915.1 2.70 ± 0.16 2914.42 3.06 ± 0.15 2914.5 3 0.4 ri Table 6-4 Transition comparison. (Contmued) Ey EL l out of level ET (A) I out of level E'y(J) I 2919.9 1486.3 2923.8 1004.2 6.09 ± 0.92 7.98 ± 0.74 1605.7 6.82 ± 1.11 1797.0 36.27 ± 2.15 1796.83 51.08 ± 3.08 1810.5 11.39 ± 1.17 1811.33 2575.1 37.53 ± 3.32 2575.82 15.38± 1.85 27.45± 1.17 2306.5 3.00 ± 0.53 2579.5 97.00 ± 9.70 1013.0 5.67 ± 0.47 1171.9 10.99 ± 0.59 2928.1 465.8 1235.5 8.91 ± 0.71 1235.57 17.37 ± 0.6 1284.5 15.44 ± 1.09 1284.42 30.42 ± 0.72 1457.25 1610.11 6.95 ± 0.53 22.18 ± 1.88 1818.56 22.18 ± 0.67 2172.45 11.83± 0.41 2583 11.26± 1.92 2584.89 77.82 ± 7.16 1070.3 3 1809.53 17.93 ± 0.56 1809.8 3 2317.61 2588.36 1.45 ± 0.14 80.62 ± 1.69 2588.3 6.4 1818.7 10.44 ± 0.81 1996.0 0.87 ± 0.17 2172.1 6.77 ± 0.45 2313.0 2583.9 0.30 ± 0.11 32.27 ± 2.43 2927.6 8.35 ± 0.43 2928.68 2932.6 2946.7 1809.5 15.00 ± 0.88 2177.0 5.24 ± 0.37 2317.5 2588.2 1.94 ± 0.18 77.82 ± 4.03 1836.0 0.13 ± 0.02 2015.3 2602.5 8.43 ± 0.68 88.45 ± 5.32 2949.3 3.00 ± 0.25 1236.4 2584.7 L 110 Table 6-4 Transition comparison. (Continued) EL E7 I out of level 2964.1 E7 (A) 638.35 I out of level Ey(T) 953 1048.7 4.79 ± 0.43 1155.48 6.25± 0.76 1414.3 6.07 ± 0.56 1414.4 1530.3 1.29 ± 0.15 1530.07 2.94 ± 0.25 1646.1 5.87 ± 0.51 1645.92 19.9 ± 0.49 1682.3 1.88 ± 0.19 1841.147 2033.89 15.54 ± 1.9 40.93 ± 0.95 3 1646 4 1840.6 5 11.2 ± 0.4 1841.0 9.20 ± 0.56 2033.9 2209.1 24.51 ± 1.38 2619.1 44.28 ± 2.28 2050.9 31.83 ± 2.44 2225.9 29.85 ± 2.08 2226.01 31.55 ± 2.1 2637.2 38.32 ± 3.09 2636.93 49.48 ± 1.16 2033.8 <+5.9 2.10 ± 0.17 2981.5 1047.9 1714.65 18.98 ± 1.86 21.14 ± 10.73 ± 1.46 2058.47 24.07 ± 2.11 2644.74 44.07 ± 2.76 830.0 0.74 ± 0.44 829.57 3.51 ± 0.92 1394.1 12.57 ± 1.45 1393.86 19.75 ± 0.52 1684.8 4.42 ± 0.87 1876.4 3.85 ± 0.38 1890.4 6.59 ± 0.84 2069.1 26.34 ± 1.55 2069 39.45 ± 0.82 2655.1 38.81 ± 3.30 23.72 ± 0.68 3001.2 6.68 ± 0.45 2655.29 2999.69 837.08 5.6 ± 0.29 1167 3.29 ± 0.69 1363.39 7.13 ± 0.43 1732.42 3.16 ± 0.28 837.4 1.39 ± 0.81 1090.9 5.34 ± 0.54 1199.4 2.40 ± 0.26 1690.2 7.04 ± 1.18 1897.1 6.60 ± 0.93 3 2619.7 -0.09 860.84 2989.02 3006.5 0.9 1048.1 2348.8 2999.8 I 3.24 ± 0.42 13.57 ± 0.22 2075.5 9.12 ± 1.31 2076.21 10.28 ± 0.4 2251.2 19.55 ± 1.41 2251.41 21.86 ± 0.49 2251.7 1.5 2662.3 48.56 ± 6.17 2662.55 46.64 ± 0.87 2663 3.5 3006.63 2.05 ± 0.07 111 Table 6-4 Transition comparison. (Continued) EL Ey 3009.4 1168.3 8.96 ± 2.80 1253.1 5.03 ± 0.49 1364.1 1.00 ± 1.14 3012.1 3025.3 3042.3 l out of level Ey (A) I out of level 1253.48 11.61 ± 0.61 10.32 ± 0.44 1690.6 7.33 ± 0.92 1690.68 1694.5 4.40 ± 0.84 1694.6 1886.4 9.37 ± 0.74 1886.08 15.52 ± 1.01 2078.8 2665.0 20.16 ± 1.48 2078.63 17.58 ± 0.81 41.52 ± 8.97 2665.18 36.07 ± 0.94 3008.4 2.22 ± 0.15 681.6 <1.0 810.44 5.03 ± 0.58 3.96 ± 0.39 1096.6 10.06 ± 0.97 15.87 ± 1.93 1902.867 8.99 ± 0.78 2257.22 2668.0 75.14 ± 9.30 2668.13 1916.1 14.83 ± 1.94 2270.0 4.31 ± 0.60 2681.0 80.87 ± 8.97 8.91 ± 0.4 1000.41 1901.9 2256.6 Ey(T) 6.81 ± 1.3 7.65 ± 0.49 66.49 ± 1.3 1915.1 2680.5 1 3023 2 1126.9 5.55 ± 0.47 1437.1 11.03 ± 1.26 1436.67 1727.4 17.61 ± 2.24 1727.72 22.31 ± 0.5 1727.8 0.8 1933.2 8.77 ± 0.98 1932.94 10.99 ± 0.54 1932.6 0.6 2111.7 2697.8 3.52 ± 0.70 2697.99 53.9± 1.15 53.52 ± 4.11 1202.7 12.8 ± 0.37 1436 3066.5 1613.5 1732.3 15.31 ± 1.29 2702.8 64.76 ± 5.09 1307.8 0.80 ± 0.28 2311.5 2722.2 10.43 ± 0.82 19.92 ± 3.23 1944.8 3074.86 5.8 ± 2312 94.2 ± 2.71 1792.71 76.85 ± 5.76 1965.42 23.15 ± 1.34 88.77 ± 7.00 0.7 4 2697.9 <0.22 3042.1 3047.1 0.6 2 112 Table 6-4 Transition comparison. (Continued) EL Ey I out of level 3080.3 1164.1 8.72 ± 1.49 1646.3 17.92 ± 1.49 1761.7 32.44 ± 2.98 1956.8 10.48 ± 1.03 2150.2 15.70 ± 1.25 14.73 ± 1.32 2324.4 Ey (A) I out of level 1761.22 61.98 ± 3.48 2324.32 38.02 ± 2.02 3085.3 Ey(T) 155.1 1442 1802.6 3088.3 2740.8 54.59 ± 23.27 3085.7 45.41 ± 7.33 1965.5 2334.0 13.73 ± 1.28 2743.9 4.83 ± 0.58 76.64 ± 10.68 3088.5 4.79 ± 1.65 2168.6 2754.5 22.96 ± 1.61 3098.9 77.04 ± 9.37 3106.6 2350.0 30.39 ± 2.90 3107.1 69.61 ± 4.09 3110.9 3112.5 3122.6 3132.4 2181.7 23.34 ± 2.73 2497.0 2768.3 28.29 ± 4.51 48.37 ± 6.02 2367.5 14.86 ± 1.86 2778.2 85.14 ± 10.82 2201.8 32.26 ± 3.12 2787.9 67.74 ± 9.26 2 1.6 2741 2 3084.5 1 2335 100 ± 5.63 500.23 2168.44 2754.7 33.17 ± 8.09 2169 62.7 ± 1.21 2754.7 2 805.84 36 ± 1.56 1131 3 2761.2 3106.5 1 2350.3 4.13 ± 0.65 25.56 ± 1.56 2761.15 19.33 ± 0.78 3105.45 19.11 ± 0.78 2495.53 100 ± 2.17 583 23.84 ± 2.12 1171.19 31.26± 5.63 20.88± 1.01 2182.1 2768.27 3112.27 1.5 21.88 ± 0.53 2.14 ± 0.14 1 113 Table 6-4 Transition comparison. (Continued) EL Ey 3134.6 2378.7 36.99 ± 13.28 3134.9 63.01 ± 6.15 l out of level 3139.8 Ey (A) 874.85 1198.97 1331.2 2.18 ± 0.26 2092.7 4.67 ± 0.53 2208.5 9.34 ± 0.84 2382.4 11.20 ± 1.18 2525.1 15.02 ± 2.36 2795.5 3140.6 45.72 ± 5.87 11.87 ± 0.66 3143.8 3153.2 3182.5 1.33 2209.71 22.24 ± 2795.92 46.08 ± 1.02 3140.2 12.76 ± 0.31 1022.73 2020.67 21.18 ± 1.37 26.74 ± 2.41 2388.72 40.04 ± 1.26 59.34 ± 12.48 2799.81 18.76 ± 0.74 27.36 ± 3.68 5.36 ± 0.68 10.37 ± 1.01 1870.55 2043.8 2223.4 2397.2 20.27 ± 2.41 2043.787 2808.8 43.26 ± 5.23 2795.7 3140.3 1.7 68.97 ± 2051.5 2815.5 12 3159.5 2 2821.3 3164.5 2 9.2 5.05 ± 0.71 15.70 ± 1.38 2233.4 15.42 ± 2.47 2820.6 84.58 ± 10.58 2059.2 2.2 20.02 ± 1.16 2388.8 2799.2 1870.9 1825.2 1.28 13.92 ± 1.69 1347.1 Ey(T) 2.97 ± 0.89 15.95 ± 2213.2 3159.6 3164.8 I out of level 11.74 ± 1.15 2251.6 13.67 ± 2.33 2426.9 22.02 ± 2.12 2838.2 52.57 ± 6.82 2808.61 3.68 ± 0 2 114 Table 6-4 Transition comparison. (Continued) EL Ey 3189.7 1875.1 42.95 ± 6.64 2259.6 30.13 ± 4.40 2844.6 26.92 ± 4.65 1 out of level Ey (A) I lout of level 3191.3 3205.8 E7(T 2844.5 2 3189.5 1 2068.8 2 2260.1 2 2575.8 3 1290.4 2 3 1365.8 1772.1 13.19 ± 10.53 1886 1891.3 2275.4 8.85 ± 1.33 2449.9 6.00 ± 0.73 2861.1 47.31 ± 3.22 3206.2 24.64 ± 1.36 3212.9 3226.3 1521.2 13.63 ± 1.51 1894.3 14.10 ± 1.11 1896.9 9.49 ± 1.59 2102.8 11.53 ± 1.51 2281.3 10.98 ± 1.44 2596.9 12.41 ± 1.94 2869.3 27.85 ± 1.97 2471.9 2882.0 9.66 ± 1.40 90.34 ± 7.69 3233.0 1918.0 2108.4 2479.0 2888.8 2 4 28.44 ± 3.67 2860.8 3205.5 887.32 56.1 ± 2.07 1045.31 12.31 ± 1.63 1521.57 31.59± 3.27 788.88 39.53 ± 1.57 1626.39 19.81 ± 1.67 1917.55 47.59 ± 1.2 2004.93 10.09 ± 0.83 2887.52 22.5 ± 0.74 13.92 ± 1.70 18.11 ± 2.73 39.54 ± 4.54 1.3 2 115 Table 6-4 Transition comparison. (Continued) EL Ey I out of level 3236.5 3250.9 3265.5 3269.9 3285.2 3305.3 3309.7 Ey (A) I out of level 911.73 17.02 ± 0.96 1544.3 6.08 ± 0.74 2128.2 10.42 ± 1.34 2306.0 19.19 ± 2.39 2306.15 36.82 ± 1.13 2482.2 5.00 ± 1.08 2481.75 6.63 ± 0.96 2892.7 28.23 ± 2.54 3235.3 31.06 ± 3.38 2127.3 9.09 ± 1.09 2320.1 4.64 ± 0.96 2495.4 2906.7 54.62 ± 3.80 Ey(T) 2127.8 2 2906.4 0.9 3250.7 4 1970.5 2 2940.5 1.4 31.65 ± 3.33 1951.5 27.63 ± 4.50 2140.3 20.24 ± 2.42 2335.0 18.66 ± 2.85 2921.6 33.47 ± 3.59 2655.0 42.47 ± 3.39 3269.6 57.53 ± 4.44 1344.0 5.96 ± 0.54 1528.9 2.24 ± 0.35 1970.4 2161.7 13.72 ± 1.44 1970.49 32.11 ± 0.86 10.62 ± 0.78 2162.05 21.01 ± 0.45 2176.0 5.23 ± 0.70 2940.15 46.88 ± 0.99 2354.3 7.16 ± 0.92 2940.9 55.07 ± 3.62 2181.9 30.90 ± 2.65 2961.0 69.10 ± 8.87 1021.6 54.38 ± 3.07 2554.9 19.72 ± 2.20 2965.7 25.91 ± 5.02 1343 ± 3283 4 2693.5 3 2966 3309.8 3314.7 I 2190.9 65.98 ± 5.88 2971.2 34.02 ± 7.27 5 116 Table 6-4 Transition comparison. (Continued) EL Ey 3325.2 2012.2 13.24 ± 4.24 2570.8 3.24 ± 0.39 l out of level Ey (A) I out of level 2710.7 7.55 ± 0.59 2980.5 51.58 ± 9.17 2980 2 3324.9 24.38 ± 1.41 3323.8 1 2398.4 4 2983.5 2 3328 7 2019 2 2994.5 2 3337 4 3329.0 3329.0 100.00 ± 7.94 3335.3 1642.4 23.84 ± 2.96 1785.2 23.98 ± 3.04 2211.7 25.43 ± 3.31 2405.0 26.75 ± 4.48 1424.6 5.60 ± 1.00 2021.9 2217.4 3340.8 3350.9 3359.3 3367.3 1075.87 26.3 ± 3.22 1424.76 10.31 ± 0.97 26.95 ± 1.86 2217.4 40.2 ± 1.02 2585.2 2995.2 15.97 ± 1.26 46.75 ± 4.30 2996.26 23.19 ± 0.54 3338.4 2.14 ± 0.15 2.58 ± 0.40 2420.1 100.00 ± 20.63 2044.2 2236.2 28.63 ± 5.45 13.46 ± 1.90 2428.5 15.50 ± 2.73 3015.3 42.41 ± 4.23 2436.3 16.29 ± 2.91 3023.1 83.71 ± 15.77 3381.2 3381.2 100.00 ± 7.02 3386.4 2262.4 2629.7 3042.5 3393.27 Ey(T) 2043.625 13.79 ± 3.45 2042.9 2 2428 2 2602.85 86.21 ± 2.59 2602.8 3 2075.4 1.2 2078.7 4 20.24 ± 2.11 12.30 ± 1.17 67.46 ± 6.01 2637.3 2 2778.1 0.5 117 Table 6-4 Transition comparison. (Continued) EL E1 3400.9 1484.5 L out of Ieve 1645.2 4.44 ± 0.60 13.39 ± 1.56 1758.2 11.71 ± 1.27 2276.7 14.89 ± 1.45 2644.5 16.24 ± 1.33 3056.6 39.33 ± 3.74 3413.1 Ey (A) I out of level E1(T) 2093.3 2480 2655 3068.7 81.05 ± 9.39 3068.5 1 3413.4 18.95 ± 1.47 3411.5 4 3433.2 3439.2 3450.0 2324 3089 2684.1 15.90 ± 2.62 3094.8 84.10 ± 4.98 2327.2 31.93 ± 5.90 2694.3 68.07 ± 7.56 3478.9 3484.1 3499.6 2360.3 31.06 ± 3.07 2728.9 14.19 ± 1.66 3139.9 54.75 ± 10.68 1807.1 11.19 ± 1.23 2184.8 28.60 ± 3.80 2376.3 37.69 ± 3.58 2744.1 22.53 ± 2.28 2572.2 3158.3 14.09 ± 1.19 3508.9 2751.7 3164.7 4.29 ± 0.46 95.71 ± 16.19 3518.8 3174.5 100.00 ± 17.03 3502.6 2 0.9 85.91 ± 16.46 3134.5 7 3479 6 118 Table 6-4 Transition comparison. (Continued) EL Ey 3534.9 2220.9 2411.9 13.85 ± 2.23 2426.0 14.57 ± 2.77 2603.8 2779.8 12.22 ± 1.63 3190.0 37.45 ± 7.47 3535.9 1.48 ± 0.17 2608.0 3194.9 43.26 ± 10.58 2440.9 31.28 ± 6.84 2619.3 2796.7 17.85 ± 3.00 2635.9 5.52 ± 1.04 3539.0 3551.2 3567.8 3572.9 I out of level I out of level Ey(T) 17.23 ± 1.75 3.20 ± 0.45 56.74 ± 25.90 50.87 ± 4.11 2811.9 5.83 ± 0.64 3223.6 88.65 ± 16.43 2462.7 19.68 ± 3.94 80.32 ± 15.82 3228.8 Ey (A) 3574.6 3229.5 3574.6 100.00 ± 12.49 3589.4 3245.1 100.00 ± 27.83 3596.1 3251.8 100.00 ± 22.88 3620.9 3276.6 100.00 ± 20.01 3628.1 3283.9 100.00 ± 20.34 3655.7 3311.5 100.00 ± 39.03 3703.4 2772.5 100.00 ± 21.92 3709.4 3365.1 100.00 ± 23.05 3572.5 2 119 6.3.3 Upper limits on unseen transitions The following 53 transitions were published in Adam's paper35, but not seen in this work, or were placed elsewhere in the level scheme. Upper limits were calculated using the intensity of the smallest observable nearby peak in the gate of interest. In cases where the peak density was too high to defmitely eliminate a particular peak, the uncertainty in the surrounding peak areas was used as an upper limit. Table 6-5 Upper limits on transitions seen in Adam et is the initial level assigned by Adam et al. Ey (keV) L Ey (keV) UL al. but not seen in this work. L UL 603.2 930.6 0.15 1714.7 1274.3 0.13 1047.9 2989.0 2989.0 0.13 658.8 855.3 1470.6 0.09 1732.4 3006.7 0.13 0.1 687.6 1915.2 0.05 1096.6 3012.1 0.09 1776.3 2121.0 0.09 1000.4 3012.1 0.02 947.1 2264.8 0.11 810.4 3012.1 0.01 1040.6 2267.7 0.04 1944.8 0.03 2103.5 2447.8 0.07 1965.4 3067.4 3074.9 880.3 2523.8 0.04 1792.7 3074.9 0.02 684.1 2523.8 0.15 500.2 3099.0 0.01 1983.4 0.05 805.8 0.21 1171.2 3105.5 3112.5 0.04 2744.1 2598.7 2744.0 1215.2 2749.2 0.1 583 3112.5 0.01 1016.6 2772.4 2772.4 0.12 874.9 0.05 1199.0 3140.2 3140.2 0.01 2772.4 2525.4 2869.8 0.4 2020.7 3144.0 0.01 2254.4 2869.8 0.05 1022.7 3144.0 0.01 1258.5 2729.2 0.02 887.3 0.01 998.4 2914.2 0.1 1045.3 1004.2 2920.1 0.04 2004.9 3214.2 3214.2 3232.0 1457.3 2927.8 0.04 1626.4 3232.0 0.04 1610.1 2928.7 0.1 911.7 3236.9 0.01 638.4 2964.33 0.01 788.9 3236.9 0.07 1155.5 2964.33 0.1 2217.4 3340.6 0.6 860.8 2981.4 0.01 1075.9 3340.6 0.01 2644.7 2989.0 0.1 2602.9 3358.3 0.03 0.07 0.1 0.02 0.02 0.03 L1 120 Angular correlation 6.4 6.4.1 Determination of correlation coefficients The original data files were resorted to create a separate matrix of coincidence data for each of the five angles: 42°, 71°, 109°, 138°, and 180°. The product of the two relative efficiencies for each detector that recorded a 7ray in a coincidence event was used to adjust each event to represent the true number of events. The matrices were sliced at a particular energy in the same manner as the combined coincidence files to produce five separate coincidence projection spectra. The peak of interest was fit in the spectrum corresponding to each of the five angles. For a given transition, the procedure was performed twice. For example, the 586 keV peak was fit in each angle spectra gated by the 344 keV transition, and then the 344 peak was fit in each 586 keV gated angle spectrum. An average weighted by uncertainty was used to produce the fmal accepted values. Since the process is actually two fits of the same data, and not two unique experiments, the uncertainties were averaged. In a small number of cases, the correlation from above or below only was used due to the potential for doublets in a particular gate. The uncertainty in the number of counts used for each angle is shown in 6-7. The value °Rad is the uncertainty calculated by the Radware program and aeff is a random efficiency uncertainty, estimated as 1.3% of the peak area. 6-7 Since the angular distribution function includes only even terms in cos2 9 and 121 cos4 9, supplementary angles are redundant. The counts from supplementary angles were averaged, e.g. the average of counts in a peak for the angles 42° and 138° was used; also with the angles 71° and 109°. 6.4.2 Matrix solution of distribution coefficients Values of N A22, and A were calculated by solving a matrix of simultaneous equations. Each of the three average count values from each unique angle is to be fit to the following equation x=A0+A22+AP. 6-8 6-8 can be related to 2-39 by setting A0 = N and noting that A Two matrices are created with the elements: C = WiPr(9i)P2(Oi), and 6-9 S2=wx1f(O1). The x are the number of counts at the angle O. The w1 = ---, 6-10 w1 are the weight parameters where o is the uncertainty in a measurement x,. Last, the P2 are the cr1 ordinary Legendre polynomials, evaluated at each of the three unique angles. Since only even terms are used in the angular correlation function, the values of % and yare 0, 2 and 4, which correspond respectively to row or colunm 1, 2, and 3 in the matrix C. The Akk are calculated from C inverse times S, 122 A=CSr. 6-11 7 The uncertainty in each value A A is =. 6-12 A0 This method gave similar results as an algebraic solution for a few simple tests. A sample result is seen in Figure 6-8, using the data from the 586 keV - 344 keV correlation. A summary of the angular correlation results is presented in Table 6-6. 3E+05 586 keV -344 keY Correlation 1 \ 2.E1-05 \ \ 2.B-05 / Theoretical rxdata - x . 1.EO5 0 30 60 90 Theta (degrees) Figure 6-8 Sample angular distribution fit. 120 150 180 123 Table 6-6 Angular correlation results. In some cases there is more than one acceptable solution. Where a measurement was made for the same yray in more than one cascade, the result is listed separately, and then as a weighted average. Ey-ET Spin seq. 117 - 586 0+ -* 2+ 170-1348 2+-* 2+-* 3+ 175 - 411 195 - 778 2+ -+ 3- 195 - 367 1----+ 32- 271 -344 2+-* 2+-+ 0+-* 315 - 271 2+ -+ 325 - 1109 325 - 765 3+-+ 3+-* 336 - 990 2+ -' 336 - 1261 2+ -* 336 - 990 2+-* 336 - avg 2+ -* 336 - avg 2+ -+ 352 - 586 4+-* 2+-* 219 - 1299 249-1348 4+ 368 - 586 3--* 388 - 586 411 - 344 2+-* 4+-* 428 - 1089 2+ -.+ 441 -1109 4+-+ 3+ 2+ 0+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 4+ 4+ 2+ 2+ 3+ 2+ 457 - 1314 2+ -+ 1- 472 - 411 6+-* 2+-* 2+-+ 2+-* 2+-* 4+ 354 - 411 482 - 778 491 - 1411 494 - 271 496 - 1109 504 - 930 504 3i----* 586 3+ -* 504 - avg. 3+ -* 31- 0+ 2+ 2+ 2+ 2+ 520 - 778 2---+ 3- 527 -411 4+-+ 534 - 765 2---+ 534 - 1109 2---' 4+ 2+ 2+ 2+ 558 - 703 2+-+ 2+-* 3+-+ 4+-* 558 - 271 2+--+ 563 - 411 2+-* 544 - 974 547 - 1314 558 - 527 1- 4+ 0+ 0+ 4+ -+2+ -+2+ -+2+ -+2+ -+4+ -+2+ -+2+ -+0+ -+2+ -+0+ -*2+ -+0+ -+2+ -+0+ A2 A4 -0.460 61 0.275 55 0.07171 -0.125 74 1.08 18 1.5631 0.159 24 0.077 25 0.18276 0.0811 0.84 12 0.91 11 0.16138 0.33415 0.006 40 0.004 21 -0.01921 -0.03 10 -0.27499 -0.061 75 -0.014 89 -0.324 86 -1.581 +1.0-3.4 -0.265 88 0.184 85 -0.112 99 0.06 10 0.136 36 0.110 +26-20 0.114 61 1.06020 0.7480 0.630 +43-22 4.421 7 6.344 8 0.684 496 -+2+ -+2+ -*0+ -+2+ -*0+ -*2+ -+0+ -+0+ -+2+ -*2+ -+2+ -+0+ -+0+ -*0+ -+2+ -0.07428 0.18074 -0.11222 0.02927 0.13075 0.041 21 0.060 19 -0.284 25 0.061 24 -1.418 12 0.11015 0.00716 -0.100 80 0.399 81 0.10193 -0.060 95 0.048 0.062 91 0.01 14 -0.11 14 0.15060 0.01859 0.08031 0.06264 0.14660 0.13831 0.29945 0.005 -0.18 ii -0.13 11 0.108 63 -0.180 64 -0.092 83 0.107 +3.59-2.03 -1.342 +1.093-. -9.736 +3.6-11.6 -0.05023 0.074 79 -0.040 51 -+2+ -*2+ -*2+ -*0+ -+0+ -+0+ -*0+ -*2+ -+4+ -*2+ 0.18545 0.114 29 -0.00948 0.11330 0.114 +3.3-2.1 -1.51922 0.17686 0.24270 -0.09787 0.212 39 0.005 40 0.048 41 0.04895 -0.05786 0.01550 0.10 10 -0.050 ii -0.051 85 -0.291 10 -0.00571 -0.08349 0.13 10 0.08 10 0.20547 0.07853 -0.12628 0.00974 124 Table 6-6 Angular correlation results. (Continued) Ey-Ey 578 - 1089 587 - 344 623 - 974 623 - 1318 Spin seq. 2,3+-* 2+-p 2+-* 2+-* 641 - 1261 2+ -* 2+ -* 641 -990 2+- 641 - avg. 649 - 778 2+ -* 659 -527 2+- 675 930 2+ -+ 675 - 344 675 -586 2+ 2+-+ 675 2+ -* 623 avg. avg. 2+ -p 679 - 411 679 344 3+- 679 - avg. 684 - 778 3+ (4-)_* 694 -974 2,3+- 3+ -+ 700 - 271 703 - 271 704 - 344 709 - 1348 1- --* 2+ --* 709- 2nd 2+-p 713 0+-* 2+-* 586 2---+ 713 -930 2+-f 715 - 411 731 - 1109 739 - 344 739 - 778 751 - 586 765 - 344 779 - 344 5(-)_* 788 1314 793 -778 3+-.-4 3+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 34+ 2+ 2+ 2+ 2+ 4 4+ 4+ 32+ 0+ 0+ 2+ 3+ 3+ 2+ 2+ 4+ 2+- 2+ 332+ 2+ 3----+ 2+ ---- 1- 2+-* 2+-* 0+ --* 3+-* 0+-* 34+ 4+ 795 - 344 795 - 411 813 - 344 813 - 1089 814 - 703 818 - 778 2- 2+- 3+ 0+ 3- 819-1314 2+-* 1- 4+- A2 -+2+ -*0+ -*2+ -*0+ -*2+ 0.34 ii 0.005 99 -+0+ 0.57480 0.22890 -+2+ -0.032 41 -+2+ 0.160 40 -0.22 12 -0.350 45 0.063 21 -*2+ 0.23322 -*0+ -3+ 0.022 19 0.05946 -2.91817 0.52721 0.47870 0.523 45 -0.649 52 -0.891 26 -0.843 39 0.047 54 -0.0313 0.349 41 0.070 22 0.091 23 2.450 48 2.358 +2.3-0.9 1.911 53 2.203 182 -*2+ 0.00427 -0.16927 -0.05023 -+2+ 0.054 29 -0.043 30 -0.194 29 -0.106 26 -+2+ -+0+ 0.28389 0.07694 -0.0411 0.79938 --*0+ -+2+ -*0+ -+2+ -p2+ -+2+ -*0+ -p2+ --*0+ -+4+ -*2+ -42+ -*0+ -*0+ -*0+ -+2+ -+2+ -0+ 2+ -* (3+-2+) -*0+ 2+-p A4 0.2811 0.27521 0.0010 0.18314 -0.17220 -0.09547 -42+ -+2+ -*2+ -*0+ 0.31 10 0.054 99 0.017 22 0.248 19 0.24573 -0.018 97 -0.018 22 0.75622 0.00872 -2.699 184 0.302 161 1.684 562 0.04638 0.08448 -0.16938 0.16992 -0.05773 0.19779 -0.17240 0.12327 -0.03970 -0.05980 -0.05741 -0.00627 0.02 29 -0.214 16 -0.062 15 0.179 85 0.07 48 0.285 15 -0.005 15 -0.150 89 0.07795 -0.15738 -0.12530 0.04439 0.00975 0.12352 -0.37086 0.19337 0.15329 0.03439 0.16936 -0.01275 0.01857 0.044 84 0.144 86 0.178 3-4 -0.01 10 0.183 108 0.00076 1.581 414 0.00635 4.02440 0.007 14 -0.02827 6.452 +15.2 -3.2 78.254 +oo41.3 -0.24310 -0.99813 0.02077 -0.089 99 125 Table 6-6 Angular correlation results. (Continued) Ey-Ey 832 1109 841 586 850 411 855 1314 866 - 1089 894 903 703 1109 909 - 586 Spin seq. 2+ 2+ --+ 2+2+-* 2+ 4+ -*2+ -*2+ 2---* 1- -+0+ 2- -+ 3+ 0+ 2+ 2+ 22+ -*2+ 1- 4+ 4+ 2+ 13+ 3+ 3+ 2+ 2+ 4+ 2+ -* 2,3+-* 3+ -* 915-1299 2+- 929 2+-+ 2+ -* 974 932 - 1314 937 - 411 937 344 940 - 974 952 - 1314 3+-. 0+-p -- -* 2(+/-)--+ 344 2+-* 966 - 411 2+ -* 2+-+ 966 966 970 1160 344 974 - 344 980 - 794 985 1314 990 -271 1011 - 586 1011 -344 1011 930 1011 -avg. 1016 -411 1037-1348 1052 411 1070 - 778 1084 1084 1086 1087 1090 1093 1107 1107 1109 411 1299 1314 344 1109 411 344 0+ 1--2+ 3(+) 2---+ 1- 2+-p 0+ 2+ 2+ 2+ 2+ 4+ 3+ 4+ 32+ 4+ 2- 2+2+-+ 2+-+ 2+-p 2+-+ 2+--* (4-)-_* -- -+ ----p 3+2+-* 2+-* 3+ -+ 2+2+-+ 5+-+ 0.25266 A4 -0.068 si 0.06869 0.0210 -0.09377 -*2+ -*2+ 0.22 10 -0.051 76 -0.052 74 0.002 21 0.23441 0.287 45 0.148 55 --+2+ 0.66233 0.07939 -*0+ 0.005 51 -+2+ -+2+ -0.14732 2.02683 -+2+ -+0+ -0.076 68 0.000 21 -0.235 72 1.736 +1.69-075 0.115 169 0.02342 -0.116 48 0.049M -5.842 +1.97 -4.77 0.016 74 -0.664 166 0.098 44 -+0+ -p4+ -+0+ -0.067 62 -0.025 45 0.04831 -0.01381 -0.06 10 -0.3211 0.071 79 0.006 61 -*0+ -*0+ 0.05575 -0.22827 0.05773 0.02525 -0.01518 --+0+ -0.082 16 0.094 90 0.327 86 -0.004 19 0.059 16 -0.087 96 0.453 25 -0.050 164 -0.16580 -0.23980 -0.11026 -0.01828 0.28258 -0.00425 0.02727 0.1666.4 0.104 45 0.204 56 0.16 12 0.06 12 0.185 68 0.058 so -0.001 53 0.25 12 0.13 12 -0.25964 -0.00361 0.12944 0.04699 -0.083 22 -0.0613 0.08426 -0+ -+4+ -+0 -+2+ -*2+ -+2+ -+tj+ -+2+ -+2+ -*2+ --*2+ -p0+ -+2+ -*2+ 1- -+0+ 2+ 2+ 4+ 4+ 32+ -*0+ -+0+ -+2+ -42+ -+2+ -+0+ 1124-778 2+-i 1131 -344 0+-* 1138 - 344 2+ -+ (2+ - 2+) 0+ 1138-1109 2+-p 2+ A2 0.440 50 -*0+ -0.029 96 0.54 10 -0.11680 0.22841 -0.0511 -0.168 23 -0.4512 0.19524 0.19932 0.119 65 0.333 68 -0.097 25 0.350 23 -0.02028 -0.11876 -0.02776 -0.078 63 0.797 +5.82 -0.87 -0.011 19 -0.121 62 0.091 34 0.022 68 0.12832 0.36444 0.03662 0.18246 0.034 75 -0.051 181 0.151 62 -0.222 105 0.16663 19.289 +10.31 -4.63 1.001 288 0.023 97 0.81763 -0.079 26 0.027 26 -0.166 34 126 Table 6-6 Angular correlation results. (Continued) Ey-ET 1142 - 778 1149 - 1109 1160 - 411 Spin seq. 2(+I-)--+ 3- ----* 2---' - 586 2+--+ 2+ - 778 - 344 2,3+ -* 3- --+2+ 0.193 83 0.021 85 4+-* 2+ -*0+ 0.01272 -0.101 77 1- --+0+ 0.022 36 0.063 36 -0.010 43 -*2+ -*0+ -0.079 41 0.035 41 -0.050 164 2-* 2+-* 0.21752 -0.08553 -+0+ -+2+ 0.24828 -0.00531 1-,2-3- -. 4+ 4+ 2+ 3- 0.074 60 -0.026 59 2+-* 2- -2+ 0.115 56 -0.016 62 2---* 2+ -p0+ 0.236 16 2+ --+ 2+ --+ 2+ --+ 3- -*2+ -p2+ 0.248 61 -0.021 66 -0.032 45 0.038 39 0.321 56 -0+ 0.071 38 0.072 39 0.206 44 -*0+ 0.017 19 -0.027 19 -+0+ 0.08894 -0.32 10 -*0+ -p0+ -*0+ -+2+ 0.31635 1.15840 1160 - avg. 3+-* 1186 -344 1186 -411 2+--* 1191 - 1109 - 1314 - 351 1247 - 527 -344 1264 - 778 1285-1299 1299 - 344 1314 1316 1316 1316 1319 1327 1337 1348 A4 0.01 10 -+2+ -+2+ -+0+ -+2+ 3i---+ 1261 0.03795 -0.47978 -0.07729 -0.05438 2+ 4+ 4+ 4+ 4+ 4+ 2+ 3+-* 1160 -344 1203 1204 1205 1209 1247 A2 -*2+ -*0+ - 778 - 586 - 930 - avg. - 271 - 1314 - 344 - 344 2+-* 2+ 3(4.) -+ 2+-* 2+-* 2,3--* 0+-* 3+ --+ 1360 -371 1366 - 344 2+-* 1366 - 411 1369 - 586 1372-778 4+-* -- --+ 2---* 2+ 2+ 2+ 0+ 12+ 2+ 0+ 4+ 4+ 2+ -+2+ -+2+ -0.021 43 0.18632 0.040 0.194 25 0.048 27 0.25829 0.051 31 -0.29 10 0.34 10 0.01318 -0.04735 -1.713 687 0.019 102 -0.021 27 0.011 20 0.246 125 0.25050 -,2+ -*2+ 1401 -778 1401 -974 2+--* 3- 2+--* 2+ 1406 - 778 1411 - 974 3(+)-* 3- -2+ 2+-* 1413 -344 1---+ 2+ 2+ -, 3- 3- -0.08525 -0.06834 -+2+ -+2+ -+2+ 1-,2--* -0.04269 0.02230 -0.03937 -p2+ -0.063 20 0.021 20 -0.141 69 -0.09767 -0.188 0.054 52 -0.15852 -0.11042 0.05052 -0.03942 0.199 61 0.101 70 0.172 42 0.140 45 -0.20078 0.06976 -0.082 39 -0.011 0.025 20 2.472 +4.1 -1.1 1.285 +1.02-0.34 0.11057 0.210 75 36 -0.00640 -0.0148 -0.06536 -+0+ -p2+ 0.39035 0.08587 -0.027 67 -0.073 69 -0.258 84 -p0+ 0.41976 0.07891 -0.360 155 -+0+ -+0+ 0.02674 -0.00571 0.214 74 -0.033 81 1447 -344 -+2+ 2+-+(3)-2+-0+ 0.24562 -0.01732 0.011 33 1447 - 1089 2+ -+ 3+ -+2+ -0.008 37 -0.013 37 1481 - 778 2(-)-* 3- -p2+ 0.07357 -0.01758 1421 - 778 1427 -344 1431 -974 1442 - 1109 1446 - 411 (2+) 2+-* 3-i---+ 2+ 2+ --* 2+ 2+-p 4+ -0.172 43 0.08259 -0.117 122 -0.096 121 127 Table 6-6 Angular correlation results. (Continued) Ey-Ey 1489 1109 1492 -344 1492 411 1495 - 344 1503 - 411 1519 1532 3+ --+ -- -* 778 2,3---- 411 ---+ 1536 - 411 1563 - 974 1566 - 1314 1575 1582 Spin seq. 2+ 2+-* 4+ 2+-+ 4+ (2+)- 411 1109 ----+ 2+-+ 2+-+ 3,4,5-9 2+ 4+ 34+ 4+ 2+ 1- 2,3+ --+ 4+ 2+ 32+ 32+ 2+ 30+ 2+ 1727-1314 (2+)-+ 1- 1739 - 778 1757 - 344 2,3---+ 3- 1757 -778 1757 -367 2+2+- 1757 - avg. 2+--+ 2+ -+ 1+,2+ -* 1586 - 778 2+-+ 1593 586 2+ -+ 1596 - 778 1597 - 344 2+- 1606 - 778 1631 -271 2+-+ 3(+)-+ 2+-+ 2+-+ 1667 1599 1771 586 344 1109 1779 -586 1785 - 411 1789 - 344 1792 - 1109 1799 - 586 1802 - 344 2+-+ 3+-+ 2+ -+ ----+ 2+ -+ ---+ 1903 -344 344 ----+ 1921 - 344 1956 - 344 2(+I-)-+ 1970-1314 1983 -344 1994 -344 1-,2-+ 2,3+-+ 1825 344 1857 - 344 1913 --+2+ -2+ --+0+ --+2+ -p2+ -+2+ -+2+ -+2+ -+0+ --+2+ --+0+ -+2+ -+2+ -+2+ -+0+ -+2+ -+2+ -+2+ -+0+ -+0+ -+2+ 2-- ---+ 3332+ 2+ 4+ 2+ 2+ 2+ 4+ 4+ 32+ 2+ 2+ 2+ 2+ 2+ 1- 2+ 4+ A2 0.17278 0.158 83 0.24 10 0.089 47 0.387 79 0.126 0.40 10 0.18 12 0.20 10 0.06272 -0.196 59 0.277 86 0.147 18 0.152 68 0.10329 0.30561 0.09738 0.14832 0.001 34 0.230 24 -0.072 74 A4 -0.083 0.012 84 0.04 10 -0.022 48 -0.078 -0.021 35 0.00 10 -0.3711 -0.06 10 -0.061 69 -0.196 59 0.025 88 -0.059 -0.018 68 -0.04030 0.08259 0.00837 0.02933 -0.04338 0.255 69 0.05773 0.04425 0.665 173 -0.05037 -0.15772 0.07843 -0.024 25 0.014 72 0.07539 -0.04239 -0.011 21 -+2+ -+4+ -0.150 22 0.12221 0.12221 -+0+ -+2+ -+2+ 0.288 36 -0.019 38 -0.01 14 -0.040 42 -0.24892 0.37372 0.08277 -0.874 299 -0.248 47 2+ -(3- - 2+)- 0+ 2+-+ 2+-+ 2--+ 2+-p 2+-+ 1802 -411 1810 -778 -O+ --+0+ -p0+ -p2+ -+2+ -+2+ -+2+ -+0+ -+0+ -+0+ -+0+ -0+ -+0+ -+0+ -+0+ -+2+ 0.363 24 0.335 86 -0.365 97 0.137 82 0.253 58 -0.011 52 0.23637 -0.52731 0.211 18 -0.211 81 0.36025 0.21331 0.0116 0.23850 -0.19562 -0.00422 -0.00422 0.076 27 0.081 87 0.10 14 0.089 68 0.233 62 -0.023 17 0.011 28 0.00009 -0.01345 -0.148 ii -0.662 457 -0.02650 0.041 40 -0.07828 0.23021 0.22389 -0.01429 -0.00433 -0.18 17 -0.021 53 -0.11766 0.01346 0.99055 -2.664 203 -0.14736 0.05233 128 Table 6-6 Angular correlation results. (Continued) Ey-Ey 1994 -411 2034 2043 2069 586 344 586 2079 -586 2093 -344 2094 - 271 2114 2151 2159 2159 271 344 344 411 2169 -344 2180 2185 344 344 2196 -344 2217 - 778 2251 - 411 Spin seq. 4+ 3(+) -* 2+ 1-,2-3- -* 2+ 2+-* 2+ (2+)- 2+ 2+-p 2+ 0+ 2+-* 0+ 1-,2 -* 2+ -- - 4+ 2+-* 4+ 2+,3+- 2+ 2+- 2+ 3-* 2-* 3(+)_* 3+--* (2+)--* (3-)-- 2255 -344 (2)-* 2260 344 2(-)--* 2265 -271 2342 - 344 2+- 344 344 1,2+2+ 2+-* 2384 - 344 2+ --* 2405 344 3+ -* 2518 - 344 2,3--* 2365 2375 2536 344 2i----+ 2570 -344 2i---+ 2+ -p 2584 2588 2602 344 344 344 2619 - 344 2655 -344 2681 344 2698 - 344 2703 344 2722 -344 2744 -344 2+-* -- -+ 3(+)-+ 2+-+ 2+,3,4+-+ (2+) -+ 1-f,2,3--+ 2,3-+ (2+)-* 344 344 2+,3+ -* 2861 -344 2i--+ 2+,3--* 2755 2795 2889 - 344 2+- 2+ 2+ 34+ 2+ 2+ 0+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2 2+ 2+ 2+ 2+ 2+ 2+ --*2+ -*0+ --*0+ -p2+ -*2+ -*0+ -p2+ -p2+ A2 -0.134 43 0.088 47 0.080 64 -0.021 56 0.01591 0.12515 -0.06445 0.0536 A4 -0.01441 -0.059 48 0.107 62 -0.06554 -0.031 90 -0.03216 0.02245 0.0619 -*0+ 0.164 43 0.012 39 -p2+ -0.17663 --*2+ -0.071 47 -+2+ -+0+ -*2+ -0.11494 -0.10535 -0.05045 -0.49690 -0.07663 -0.01664 -0.03645 -0.13576 0.22035 -+2+ -0.251 51 -0.011 52 -*0+ -*0+ 0.11528 0.07928 0.27 10 -0.02 1-i -+2+ -*0+ 0.01855 0.283 3I 0.01757 -0.14236 -+0+ 0.239 21 0.018 23 -0.04221 -*0+ --*0+ -+ 0.15320 0.018 -0.17863 0.200 41 -0.060 23 -0.074 w -+0+ 0.31237 0.47027 -0.05529 -0.09540 0.06631 0.06329 0.208 i -+0+ -+0+ -+0+ -+0+ -*0+ -+0+ -*0+ -*0+ -+0+ 0.044 56 0.29423 0.578 +5.4 -2.4 0.00727 -1.355 192 -0.002 25 0.15821 0.102 37 0.003 24 0.276 52 0.031 25 -0.017 45 0.27225 0.51460 -0.16873 -0.01927 0.30969 0.05872 0.209 54 -0.026 59 0.20954 -0.12951 -0.02659 0.05356 -0.1410 -*0+ -*0+ -*0+ -*0+ 0.19249 -0.13854 -0.11949 -0.06255 -+0+ -0.02 12 0.14 12 0.32 13 0.316 65 0.00938 -0.00860 -*0+ -*0+ -*0+ -*0+ 6.014 +4.11 -1.80 -0.006 63 -0.566 123 -0.02030 129 Table 6-6 Angular correlation results. (Continued) Ey-Ey 2893 - 344 2907 - 344 2941 - 344 2981 - 344 2995 - 344 3043 - 344 3165 - 344 3224 - 344 6.5 Spin seq. 2+ 2i-,3,4+--+ 2+ 1-,2 -* 2+ 2+ -* 2+ (2+) -+ 2+ 2+-* 2+,2,4+(2+) -* 2i-,3,4+- Mixing ratio 2+ 2+ 2+ -p0 A2 -0.03 10 -+0+ 0.12792 -0.00392 0.06781 -*0+ 0.248 81 -0.49 45 -0.18 39 -0.020 74 0.04 23 0.16 20 -+0+ --*0+ -0+ -*0+ -+0+ A4 0.2633 -0.0419 0.333 40 0.151 55 0.069 44 -0.04557 () calculation In cases where the spin of the initial and final level could be unambiguously determined, the 8value for a transition was found by a minimization procedure. The expected number of counts W(9) in 2-39 can be written as a function of the mixing ratio £ For a number of counts in a given angle n(8), n(e)_W(9)J2 6-13 The value of 5and the value of N were adjusted until the deepest minimum ofj was found. The solver routine in Microsoft Excel was used to minimize this function. The uncertainty in Sis the range that produces a change inj of one unit. Figure 6-9 shows the uncertainty range graphically. The measured övalues are contained in Table 6-6. In cases where it was possible to extract a 8value from more than one correlation, the weighted average of delta is presented below the values it is comprised of. 130 586 keV x2 6.0 5.0 4.0 3.0 2.0 1.0 0.0 -3.2 -3.1 -3 I I -2.9 -2.8 -2.7 Figure 6-9 Sample of X2 reduction method. The uncertainty range in Sdue to the variation of one unit inj is indicated. 6.5.1 Previous mixing ratio measurements Several publications have previously reported Svalues for transitions in 152Gd as described in 4.5. These mixing ratios are compared to this experiment in Table 6-7. The enhanced quality of the coincidence data produced by the 8ic allows precision measurement of previously published övalues and calculation of multipole mixing for many more weak transitions. 131 Table 6-7 Previously measured Svalues compared to this work. The table is not a complete report of all previously measured övalues: only the values measured for y rays assigned to the same spin and parity as this were are shown. This Work y Tagziria NDS Ferencei 0.035 195 M3/E2 -0.3<c<- 411 Kalfas Lipas 0.032 543.7 0.048 41 586 622.8 -2.95 20 0.523 45 675.1 2.20 35 I- 678.6 764.9 3.82 35 794.8 50.6 +°-41.2 778 0.009 15 937 -0.03580 970.4 -0.018 18 0.45 9 0.18 8 -3.27 +7.76- -5.4+1.5-2.6 0.018+4218 or 2.13 .i. 2.2 4 3.8 6 -4.9 1.2 -3.05 14 +1.0 5 1.0450 0.2<ö<1.5 +2.2 4 +4.1+17-11 1.84 66 -19 16 +3.8 6 3.47 +1.70-0.91 -0.4 +7-12 -0.4 +7-12 19 16 4.3 +0.7- 3.47+1.7-0.91 0.6 974 1010.7 0.033 0.18 +17-14 1.47 60 1.88 +1.93-1.06 0.23<ö1.41 0.03 +3-10 tor2.15 1086.3 1089.7 0.06 6 -0.18 14 -0.18 14 17+10-4 0.225 20+23-8 44<5<-7.1 1137.6 1185.6 0.32 6 -92 -92 -0.69 +O.46oO 1190.5 0.285 +0.064 +0.285 +0.064 1261 -0.041 35 -0.009 43 -0.016 30 1275 -0.2519 0.33 8or 1299.1 0.01620 <0.10 +0.043 17 1348.1 0.026 20 -13 +4-7 1369.2 -1.2 1-0.3 -0.5835 -13 +4-7 0.35 6 +4.3 +9-13 +4.3 +9-13 -0.285 -0.285 -0.31 29M3/E2 1209.1 0.28+0.17-0.21 -0.2014 2.592.10-0.95 <0.10 13.5 +-6.5 .1. 1411.5 1517.8 T I. -0.11 6 1586.23] 0.042 26 1596.9 1596.9 1667.4 1771 ] 1789.1 -0.034 40 -0.235 45 +0.19+3- +0.19+314 +0.259 +0.25 9 -0.28 12 +0.26+9-6 1797 >14.3 1802 <0.18 -0.1 8 -.030 25 M3/E2 +0.356 14 -0.28 12 0.26 3 +0.263 +0.26+9-6 1 -4.69 +2.66-1.28 or -0.21 8 -.3421 0.29 +9-8 E3/M2 1.1161 -0.1310 +0.9-1.6 1902.4 -2.7020 -0.114 0.4 +0.7-1.2 0.011 63 -11 2 -0.114 0.36 +25-18 0.58.07 1.47 0.60 -44<S<-7.1 I 132 Table 6-7 Previously measured övalues. (Continued.) This Work Taaziria NOS Ferer +0.274 0.30 +9-8 -0.19 l2or 1915 4.3 +4.8-1.6 -0.074 1920 0.056 33 6.04 +4.1-1.8 1955.3 2033.8 2150.9 0.27 4 I <5.9 <+5.9 -0.75<5<- -0.62 0.41 2185 0.009 28 <-0.15 0.200r2.1 2342 9 2365 2375.3 2384 2495.6 0.003 26 0.16 2 0.10638 too weak 0.31 +-38 multiple +0.158 +0.158 2518.5 0.10 +0.27-0.18 0.31 +-52 multiple -2.7 <5<- -1.7 10 0.06 multiple, including +0.21 6 +.216 2536 2619.7 -0.53 11 -0.01530 -0.098 2663 too weak Tentative <0.05 2697.9 0.38 34 I. 0.22 -0.098 0.22 1. spin I 6.6 Determination of level spin The combination of angular correlation and an analysis of the spins of the fmal levels have led to many new spin assignments. Those levels with significant difference from the published values or those that have major relevance to the band structure are described here. In all cases, level assignments have been made on the basis of coincidence. 6.6.1 1475.2 keY O level New O levels are particularly significant as a likely bandhead for a previously 133 unidentified band. The 1130 - 344 keV correlation has A44 = 0.93. only the 0-2-0 spin cascade has such a high value for the A44 coefficient. This level also matches a recently discovered4 new O state in '50Sm. The 1475 keV level was not established in Adam's paper; the TORI68 does not list an 1130 keV yray. Some evidence for this level was seen in the 152Eu decay.69 Transitions feeding from levels 2438, 2513, and 3360 keV above that feed the 1475 keV level have been identified. Most importantly, the 296 keV transition seen is identified as originating from the 1771 keV 2 level. The feeding helps support the assignment of these two levels to a new band as described in Chapter 7. The coincidence gate for 1130 keV showing the strong 344 coincidence is shown in Figure 6-10. 3443 Figure 6-10 1130 keV gated coincidence spectrum showing 344 keV coincidence and feeding transitions. 134 6.6.2 1681.1 keY 0 level The A44 = 1.1 for the 1337 - 344 keV correlation, a strong indication of Ot This is a new level, consisting of the previously unassigned 1337 keV yray and a 750 keV yray feeding the 930 keV level. The expected E0 component at 1680.8 keV would likely be below detection limits of previous conversion electron studies. 6.6.3 1839.9 keV 3 level Both Adam's paper and the TORI list this level as 2t Several of the angular distribution measurements indicate spin 3. For example, the 909 586 keV correlation and the 2084 422 keV correlations both indicate spin 3, with spin 2 far outside the uncertainty. Furthermore, the lack of a 0 feeding, common to almost all of the other 2 levels favors the 3 assignment. The large E2 component in the 909 keV transition indicates positive parity. 6.6.4 1915.5 keY 3 level The fof3, 4f in the TORI data comes from d,d' measurements, which have a lower confidence for spin determination. The 1160 411 keV correlation has a negative A22, which eliminates spin 2, and the 1160 344 keV crossover measurement eliminates all choices but spin 3. The choice of positive parity is consistent with feeding from above and is supported by the lack of a feeding to the 1 level at 1314 keV. 135 6.6.5 Other spin assignments Unambiguous spin and parity assignments have been made for several other previously undetermined levels. These include 2133.3 keV, 2299.6 keV, 2401.4 keV, 1961.7 keV, 1975.5 keV, 2437.4 keV, 2539.9 keV, 2544.2 keV, 2880.4 keY, 2927.7 keV, 2999.4 keV, and 3139.4 keV. Table 6-3 shows the spins of these levels in comparison to previous publications, the transitions that depopulate them can be found in Table 6-2. 6.7 EO transition strength calculation The E0 strengths reported in this study are all calculated using the method described in 2.1.5. That method used the published conversion coefficients (a) and the measured mixing ratio values (8) to calculate the E0 intensity. In certain cases it is also possible to extract the E0 intensity from the angular correlation measurements using de-orientation coefficients. For example, correlations with the 930 keV yray and the 344 keY 7-ray can be used to find the E0 strength in the 586 keV 7-ray. The Akk for the 675 keV transition in coincidence with the 930 keV transition from the 930 keV level is the product of the relevant Ak and Bk as defined in 2-46. A (675-930) = Ak (930) Bk (675) 6-14 The Akk for the 675 keV crossover correlation with the 344 keV 7-ray depends on three factors: A (675-344) = Ak (344)Bk (675)Uk (586) 6-15 136 Since the 930 keY and 344 keY transitions both connect spin and parity 2 to 0, the Ak (344) = Ak (930). The ratio of both Akk leaves oniy the de-orientation coefficient. A (675-344) Uk(586) A (675-930) 6-16 The de-orientation coefficient defined in 2-51 depends on a sum of the effects from each multipolarity present. Since transitions that use E0 only connect levels of the same spin and parity, the dominant mulipolarities in such a transition are E0, Mi andE2, Uk =U° +u +U. 6-17 The coefficients in 6-17 depend on the intensity of each multipolarity, IEOU (2,2,0) + IMIU (2,2,1) + 1E2U (2,2,2) k 6-18 JEO+JMI+1E2 6-18 can be solved to determine the E0 strength for the 586 keV transition. The calculations to fmd the Uk factors 7-rays feeding the 930 keV level. using this method were performed using several A similar calculation has been performed for the same feeding yray in correlation with the 586 keV 7-ray in addition to correlations with the 930 keV 7-ray. The results can be seen in Table 6-8. The Uk values in the columns on the right are expected to be equal for the same k. Poor agreement among the calculated numbers is due to the relatively large uncertainties in the angular correlations. Since the E0 intensity is only a small fraction of the Uk, as indicated in 6-18, 137 Table 6-8 Calculation of Uk factors using ratios of angular correlation factors. I 586 corr. A22 344 corr. I 930 corr I 344-930 A22 A22 A A A(586) 6751 0.234 22 0.064 22 -0.350 45 0.446 15 0.091 24 0.071 23 0.349 42 3871-0.28525 -0.024 27 0.20743 0.061 24 0.008 27 0.110 46 10101-0.11026 1-0.00525 -0.01928 0.28259 0.027 28 28 0.030 28 E i I I 351I0.075 I 713! -0.16939 0.046 39 586-344 U2(586) U4(586) U2(586) unc U4(586) 0.122 0584 -0.182 0067 0.203 0069 -0.212 0.145 -0.117 0.131 0.038 5779 -0.274 3 0.077 0249 -0.038 6420 -0.067 0.100 0.076 3.874 1-0.121 63 0.44415 -0.2743 -0.224 0255 1.537 0261 0.055 43 0.243 63 0.444 15 0.226 0187 -0.325 0.527 0.140 45 !-o.o6o 66 -2.311 2649 -1.284 0057 -0.456 0497 0.203 9.624 75375 0.737 !-0.077 -o.125 79 -0.273 3 0.444 15 ! 0.17093 -o.013 101 : -0.274 3 0.444 15 -0.2743 0107 the angular correlation error will produce a large uncertainty in the calculated E0 strength. The resulting uncertainty is much larger than the error provided by published conversion electron measurements. Therefore this method will not be sensitive enough to produce a useful value of E0 strength. The 586 keV transition is the strongest 7-ray that this method can be applied to; Uk calculations with weaker transitions, such as the 765 keV 7-ray showed even less consistent results. The calculation of electric monopole intensities in this work uses the method described in 2.1.5. 138 Chapter 7 Band Structure The location of the N = 88 isotones in the transition between spherical and deformed nuclei creates a difficult system to model. No current structure model describes the '52Gd band structure completely, though various models can be used to explain different parts of the complicated band structure. Due to the possible presence of competing types of structures, the failure of a particular model to explain the whole structure does not necessarily make that model entirely invalid. The low-energy positive-parity excited states in '52Gd can be organized into six quasirotational bands and one potential bandhead, shown in Figure 7-1. The ground-state band (g.s.b.) 2691 io 2300 2307 (7 ) 1098 (6 2139 8 1860 3 f747( S 1915 15506 I3 1226 + 2 y-band 1282 1941 i )' 1605 2 1434 2 1771 2 1668 4+ 4 + 1475 o J 2 1318 1109 2 930 0 1047 755 615 2 344 /3 - band 0 152 Gd g.s.b Figure 7-1 Positive parity band structure diagram for some low-lying states in '52Gd. 139 yband, flband, flyband, and i band have been established previously, though the 1915 keV .P = 3 member of the fiband has replaced the previously suggested 1839 keV = 3 level. This replacement better matches the spacing of the 3 member of the yband with respect to the g.s. band. The j band starting with the new 0 state at 1475 keV is previously unpublished. The 1941 keV level is indicated as a possible bandhead of a band associated with the i band, due to its spin and parity and the energy spacing relative to the O state in the i band. Higher members of this band are thus far elusive. A 3 level is expected at around 2200 keV, there are several choices with undetermined spin listed in Table 6-2. The parent decay spin of 2 means that higher energy 4 levels are likely to be very weakly populated. Other assignments have been made based on applicability to particular models and systematic trends seen in neighboring nuclei. Some of the possible model explanations are explored in 7.1.2 through 7.1.5. 7.1 Nuclear structure model applications to '52Gd 7.1.1 Quasirotational bands The pattern of low energy excited levels seen in '52Gd can be separated into bands based on the models described in Chapter 3. However, the transitional nature of this nucleus demands a combination of these models. Much of the band description has been described previously, though the structure is still open to interpretation. In 140 general, the bands in Figure 7-1 are organized as rotational levels built on underlying vibrations. The energies of the ground-state, yand fibands are plotted versus the expected rotational spacing in Figure 7-2. If the '52Gd excited states in these bands arose from a true deformed rotor, Figure 7-2 would show a linear relationship with slope as predicted by 3-13. Though the plots are somewhat linear, the character of these bands is not well explained by a pure rotor since the moment of inertia (inversely proportional to the slope of Figure 7-2) is not constant. The relative moment of inertia implied by the rotor model for each level in the band is plotted in Figure 7-3. The g.s. and flbands have some similar though nonlinear behavior and the relative moment for the yband 3000 Rotational band spacing - 2S00 '1500 ig.sT 1000 T 5001 0 20 40 J(.J+1) 60 80 100 120 Figure 7-2 Energy levels for selected bands showing deviation from rotational spacing. 141 Relative moment of inertia 5 4.5 4 3.5 3 0.5 0 0 2 1 3 Band member 4 5 6 Figure 7-3 The moment of inertia implied by a pure rotor for selected bands. The ordinate has units of inverse energy. fluctuates as spin increases. Although the rotor model provides a basis for organizing the excited states, the rotational limit is not a good match for '52Gd. 7.1.2 Ground state band The vibrational model can also be applied to the '52Gd structure. The ground state band has spacing near the expected R4 = 2.00 of a vibrator, as shown in Figure 7-4: R _E(4)=219 E(2) 7-1 Some of the measured B(E2) values match the vibrator predictions as well. The lifetimes of five states have been measured by Johnson et al. ;70 most of these are 142 4 4 2 0 '52Gd gs.b. Figure 7-4 Low-lying members of the ground-state band of '52Gd. for transitions among low-lying members of the ground-state band. The absolute B(E2) values calculated from the lifetimes measured by Johnson et al. are shown in Table 7-1. The ratio of some of the observed B(E2) values in Table 7-1 also match the Table 7-1 Lifetimes and absolute B(E2) Transition values, as reported by Johnson et t112 Ji-*Jf (keV) 2; -o; 344.i (j,$) 34.2±I. al. B(E2) (e b2) U.33±CJ.02 2;, 411.1 7.2±0.4 0.64±0.04 6, *4, 471.9 2.5±0.5 0.95±0.19 586.3 7.3±0.6 0.077±0.006 271.1 37±8 0.85+0.19 4 2 2 O*2 143 prediction of 3-7, which further indicates the possible vibrational nature of the 152Gd nucleus. 2) B(E2;2 O) B(E2;4 =1.94. (6-12) However, if '52Gd is a vibrator, then we expect a 2 phonon triplet (Ok, 2, 4) at twice the energy of the first 2 (Figure 3-2). Such a triplet of states is not observed. The presence of EO transitions is an additional argument against a spherical vibrational structure. The form of the EO operator as described by Wood = 0, ±2. Thus E0 transitions between, for example, the 2fl and 2 et al.7 g.s. b.., has would not be observed in a vibrational nucleus. Table 7-2 shows that such forbidden E0 transitions are observed. 7.1.3 Variable moment of inertia model Though the rotational description predicts R4 = 3.33, the rotational prescription can be modified to explain the adjustment in spacing. The Variable Moment of Inertia (VMI) model has some success by describing the nucleus as a "soft" rotor. If the moment of inertia in 3-13 is allowed to grow as the spin of the band increases, the spacing of the levels decreases. A qualitative depiction of the shift is shown in Figure 7-5. Mariscotti et al.7' use a linear approximation of the moment of inertia to achieve a good fit of ground state rotational band spacing across a large range of nuclei. While the VMI model helps explain the ground state quasirotational spacing, it does not explain other band structures observed, such as the band with low energy spins 0, 2, 144 6+ 42A \ 4+ 20A \ 2+ 6A 2+ 0+ 0 0+ Figure 7-5 Change in ground state band spacing due to VMI. The adjustment to ground-state band level spacing is caused by allowing the moment of inertia to vary with spin. and 4 starting at 615 keV. Furthermore, the change in moment of inertia is not consistent for increase of spin between different bands, as seen in Figure 7-3. 7.1.4 Soft rotor The VMI can be extended to explain rotational bands as well as the ground state band. The model can be called a "soft" rotor model. The deformed rotational model described in 3.3.3 can also be described as a soft rotor. Such a combination of quasi-rotational bands built on vibrational band heads can extend across much of the observed pattern of bands seen in '52Gd. The 615 keV level has been described as a /3 145 vibration with rotational levels 930 keV, 1282 keV , etc. (Figure 7-1) built on it. The 1109 keV level can be described as a yvibration with 1434 keV, 1550 keV, etc as rotational states in this band. The two-phonon 0 /3/3 vibration should be at approximately twice the first 0 energy at 1230 keV. The 1048 keV level along with the 1318 keV spin 2 are near enough to this energy to be considered a /3/3 band. The flyvibration is expected near the sum of the /3(615 keV) and y (1109 keV) vibrations, indeed there is an identifiable band starting at 1606 keV. The soft rotor predictions begin to deviate substantially from the observed levels after about 1.7 MeV. Continuing the prescription predicts a 'vibration at 2218 keV. This is quite high in energy to be populated at either of the possible couplings: 0 or 4, so its existence cannot be detected in this experiment. A triple phonon J8/3,8 vibration would be expected at 1845 keV. The 0 at 1475 might be the 0 combination of three phonons, but the energy difference between experiment and model is rapidly growing. The predicted energies from combinations of many vibrational phonons produce energies far from the levels in the experimental data. 7.1.5 Anharmonic vibrator The vibrator predicts the spins observed in some bands such as the /3 band seen in Figure 3-2, but the energy spacings are inconsistent with the predictions of the harmonic vibrator model. The energies can be adjusted by adding additional terms to the vibrator Hamiltonian to produce an anharmonic vibrator. The energy of the 146 vibrational model 3-4 results from the Hamiltonian 3-3. That Hamiltonian contains one of each b and bt, the creation and annihilation operators for vibrational phonons. Adding terms with multiple operators can cause levels to mix and changes the energies. One example is the following Hamiltonian: HVIb a{bb+J+B(b +b) 7-2 Adjusting the parameter B can reproduce some of the observed level spacing. However, this form of the operator allows transitions of AN> 1. In the case of the '52Gd band labeled ,8 this would indicate that the transition from the 2 930 keV level to the 0 ground state is allowed. In the vibrational model, the 930 keV level would be a two-phonon level; the 586 keV transition would be a one-phonon transition while the 930 keV to ground state 0 transition would be a two-phonon change. The relative B(E2) value for the 930 keV transition is two orders of magnitude smaller than the 586 keV transition, indicating that it is basically forbidden, as shown in Figure 7-6. While the adjusted anharmonic vibrator can explain the fi band or other single bands, different bands require different adjustments to fit the model. For example, the 930 keV 2 level of the flband would be a two-phonon vibrator, expected at 1230 keV (Figure 3-2), or twice the one phonon 615 keV level. If the B parameter is adjusted to make the two-phonon level at 930 keV, then what would be the two-phonon bandhead of the yband at 1109 keV is now far outside the model. The band labeled /Jyis also not predicted by the anharmonic vibrator. Other parameters or different models are required to explain other bands or encompass all the band structure simultaneously. 147 R 6' D g930 2+ N=1 I 2+ LN2 344_k. 0+ Figure 7-6 Partial level diagram showing B(E2) values that differ from the anharmonic vibrator. 7.1.6 Interacting boson model (IBM) A second form of the anharmonic vibrator is based on the concept of nucleon pairs with total angular momentum J = 0 (s bosons) or J = 2 (d bosons) dominating low-energy structure. The basis of the Interacting Boson Model (IBM) is an anharmonic vibrator. Assuming the ground state has all can be predicted as the energy Ed s bosons, the energy of a state of all d bosons plus an interaction between boson pairs: c = 6dd + 7-3 . (d2) JO,2,4 The C are proportional to the energy shift of the 0, and dt 2 and 4 levels. The d are creation and annihilation operators for d bosons. The superscript (J) 148 indicates that the d bosons are coupled to produce the proper total angular momentum: 0, 2, or 4. The additional parameters allow the energies to be more closely matched to the level energies determined by experiment. The Hamiltonian 7-3 is a simplified version of the IBM Hamiltonian. This form preserves the AN = 1 rule of the vibrator model. Some higher order terms that can be added mix states with different numbers of bosons and account for interaction between s and d boson pairs. The Hamiltonian 7-3 accounts for all valence particles indiscriminately, some IBM models include terms that account for the difference between neutrons and protons. Several of the models mentioned in 4.6 use the IBM or similar variants. Many IBM calculations accurately predict much of the observed energy spacing. Adam et al.35 achieve and average deviation for 13 predicted level energies of only 53 keV with an IBM calculation. Tagziria et al.53 predict the lowest five levels almost exactly, the match at higher energies is worse. The major benefit to the IBM model is the ability to predict transition strengths. The model as used by Lipas et al.55 is able to predict collective Mi transitions. Several of the experimentally measured 8 values indicate substantial Mi admixture in collective states. For example, the 8= -2.9 of the 2fl* 2 g.s. 586 keV transition indicates approximately 10% Mi admixture. The Lipas et al. model predicts 8 -6.1. Tagziria et al. also predict three Svalues; the match between experiment and calculation may indicate the underlying reasons for the structure. Unfortunately, since the model parameters are generally based on the 149 experimental data, the IBM generally lacks predictive power. The success of the IBM rarely extends far outside the model space, and thus thrther model extensions are required to describe the remaining bands. For the case of '52Gd, Adam et al. conclude that "None of the models explain the data in a completely satisfactory way." 7.2 Multipole transition strengths 7.2.1 Monopole transition intensity As described in 2.1.5, strong monopole transitions can indicate mixing of different shapes between levels. The 1:0 calculated from 2-32 are shown in Table 7-2. Table 7-2 Electric monopole intensities IAE for selected transitions and relevant conversion coefficients. Ey M1 *1O3 cNaK iü 387.8 420.00 110.00 K 10 41.93 3 E2 3 lv tXK 22.31 TEQ ,E0 1K 2.86 0.82 Band Desc -+ 2+ P I_i .1+ 526.9 82.00 9.00 19.15 9.90 3.16 fi 0.44 -p '3+ 586.3 20.20 2.10 14.67 7.66 0.94 0.17 "/3 '3+ -* '3+ 622.8 675.0 10.90 6.00 1.70 1.50 12.59 10.31 6.61 5.48 -0.01 -0.01 0.03 0.03 "ir '3+ '3+ "fir "P '3+ 764.9 5.70 1.30 7.58 4.12 0.07 '3+ -+ 0.07 3.70 1.80 4.75 2.71 0.00 0.01 'I2 -4 '3+ 974.1 5.00 0.60 2.40 4.23 0.12 0.03 1010.6 5.70 1.40 3.87 2.27 0.02 0.01 "ir "17 '3+ -+ '3+ "ir g.s. '3+ '3+ 928.4 g.s. '3+ '3+ - "P 150 Table 7-3 Electric monopole intensities. (Continued) M1* aK Ey a*1O3 1137.6 3.00 0.60 2.93 1261.3 2.20 0.40 1596.9 1.01 1771.4 3 lu aK 2* 1EO 1E0 1K CIK Band Desc. 1.79 0.00 0.01 12 -* 2.30 1.46 0.00 0.01 /Jy -* g.s. 0.23 0.99 3.16 0.00 0.00 'ir -+ g.s. 1.41 0.27 0.88 3.16 0.01 0.00 L20 1778.8 1.60 0.40 0.87 3.16 0.00 0.00 b17 1857.5 0.76 0.28 0.82 3.16 -0.07 0.02 2093.2 1.25 0.24 0.67 3.16 0.02 0.01 2365.1 1.20 0.30 0.50 3.16 0.02 0.01 Wood et square radius al.7 (r2). Z.103 ii L4 ii 2+ 7 -+ -* g.s. - g.s. - describe how E0 transition rates are correlated to the root-mean In that model, the E0 transitions could be caused by mixing of a spherical ground state band with a deformed shape in the fi band. It could be said that the strong monopole transitions in Table 7-2 are between bands with different intrinsic shapes. The observed monopole intensities in these transition nuclei are consistent with a mixing of spherical and deformed shapes, a reflection of the transitional nature of '52Gd. All of the measured monopole strengths above 1 MeV are not significantly different from zero. The decline in the probability of internal conversion relative to y emission with increase in energy is one reason. Furthermore, the high-energy states have less distinct shapes so that changing the shape without changing the angular momentum becomes less probable. 151 7.2.2 Relative B(E2) values in positive parity bands The vibrational and rotational models make strong predictions about the expected relative B(E2) values. The transitional nature of 52Gd results in quasirotational bands that do not always follow these predictions well. However, selected relative B(E2) values support much of the band structure and help clarify the assignments that have been made. Figure 7-7 and Figure 7-8 show some relative B(E2) values relevant to the band structure. The values are calculated as described in 2.1.2 and are normalized out of a given level. Since decay to the ground state band requires the annihilation of only one phonon, decays to the g.s. band from one-phonon bands are relatively strong. Decays into other bands require the simultaneous annihilation and creation of vibrational phonons; these dual step processes are hindered. Decays within the band should generally be strongest, since the change of rotation involves the whole nucleus. However, these quasirotational bands do not always follow these prescriptions. In the yband, the largest B(E2) values for the 2 and 3 states feed into the ground state rotational band. Electric quadrupole transitions within the band are strongest from the 4 state and the second strongest for the 325 keV yray from the 3 level. The 116 keV difference between the 4 and 3 levels of the yband is probably suppressed due to the E5 energy dependence for E2 transitions. The observation of even a weak 116 keV tray would result in a large from the yband to the 2 B(E2). E2 strengths for transitions and O members of the flband are generally smaller, though 152 not weak. The wavefunctions that describe these bands are probably not as pure as the band designation implies; mixing between bands is likely the cause of these enhanced interband transitions. A similar pattern of enhanced transition strength to the g.s. band and strong inter-band transitions is seen in the fi band. None of the measured values from this experiment are high enough to show B(E2) values for transitions into the yband from r I 4 ±_____ 1915 -1860 -1605 -1550 2 -f - 1434 - 1318 4- 1282 1226 2 -1109 -1047 c4N -930 -755 -- -615 -344 -0 0 152 Gd g.s.b y-band f3-band 13y-band Figure 7-7 Band structure diagram showing B(E2) values. The values from a given level are normalized to highlight particular features of the structure. 153 the /1 band, but it is expected that they are somewhat restricted in the manner described above for y* /ltransitions. In this band, the B(E2) values to the g.s. are about equal to the intraband B(E2) values. The more weakly populated and higher energy bands have fewer calculable intraband B(E2) values. The i band shown in Figure 7-8 has a strong preference to decay by intraband transitions and then decays strongly into the 'band. There are not --1941 2 1860 1771 1692 '7- ___f_ 1550 - -1475 0 1318 1282 1226 -1109 -1047 II- 930 - 755 -615 . j-band i-band iy-baacl Figure 7-8 Selected B(E2) values for additional bands in '52Gd. 0 154 enough measured B(E2) values for thej band to make a defmite judgment about feeding preferences. The B(E2) values for the iyband are shown only to indicate the possible relationships with other bands. Since the 2 state at 1941 is only a suggested band head and has no other band members, so no mtraband transitions are available. 7.3 Other bands and excited states 73.1 Octupole states Two negative parity bands, seen in Figure 7-9, can be established from the observed levels. In this study, the spin parity assignments were confirmed for the 3, 1, and 5 levels in the K = 0 band, and the 2, 3 and tentative (4) in the K = 1 band. The angular correlation data for transitions from the 1807 keV level agree with 4, but none of the evidence is strong enough to make a defmite assignment. The inverted order of the 3 and 1 members of the K = 0 band is thought to be due to mixing with other negative parity states33. The Coriolis force distortion in a rotational band can mix odd states with iK = 1. The mixed 3 states are pushed apart in energy leading to reversed spin order in the K = 0 band but normal ordering in the K = 1 band. 7.3.2 Promoted pair basis states It has been suggested69' 72 that some of the observed levels can be explained in terms of proton pair promotion across the subshell gap at Z = 64 (see section 3.1). 155 11 2814 (6 9 2331 7 1880 2713 ) (4 -'---_-----1807 3 - _ -l692 - -/----'- 1644 1 1471 1314 3 1123 K=l 0 keV 152 Gdg.s Figure 7-9 Negative parity bands in '52Gd. The pair excitation energy for this gap is roughly 1 MeV. The 615 keV level could be explained as the result of promoting a proton pair across the subshell gap. In this picture of the band structure, the 1109 keV and 1047 keV levels are one-phonon y - and fl-vibrations as in the soft rotor. Soft rotor states similar the first two can be built upon the pair excitation at 615 keV. If the 615 keV is called g', then the 1475 keV level could be considered a fi' excitation and the 1606 a bandhead. Further systematic investigation of this pattern is necessary to assess its validity. 7.3.3 Shell model excitations Above approximately 1.8 MeV, the level density becomes increasingly large, 156 and the models presented so far fail to accurately predict spins and energies. At this energy, it becomes possible to separate a pair of protons or neutrons and excite one of them to a new subshell. Empirically, the energy required for such an excitation is near 2 MeV. The possible configurations are large in number and give rise to a multitude of possible states. For example, if a valence proton is promoted to 2d312, the angular momentum of the pair can couple with the remaining 2d512 hole to produce excitations with integer spin from 1 to 4. The multitude of2 levels seen in '52Gd above 2 MeV is an indication of broken pair states. 7.4 Band structure systematics Patterns of excites states observed in many of the isotones with 88 neutrons h1112 S112 3(2 d312 Z=64 d512 _ 5/2 Figure 7-10 Example of a single nucleon excitation across the Z = 64 subshell gap. The resulting d512 hole can couple to the d312 excited particle to produce spin 1 to 4. 157 show much similarity. Figure 4-2 shows a comparison of the ground-state andy' bands of several N = 88 isotones. Similarities can also be seen in other bands in several of these nuclei. The flbands of even proton number isotopes for Z = 60 through Z = 66 are shown in Figure 7-11. The increase in deformation as protons are added decreases the y-band energies from left to right in the figure, but the energy spacing is very consistent. A comparison of the ybands for the same isotones is shown in Figure 7-12. The same general decrease in the band member energies is seen as the number of protons increases. 10 8 8 2726 6 2149 I 0 2300 1602 4 1227 2139 8-'- 2163 6 1668 6 1658 1822 1747 4 6 S" 1448 'i 2 1171 0 917_ 1282 -_± 1252 1045 4 765 930 ._2 905 0 661 '48Nd f3'-.p±iLi4o 615 Sin '52Gd /3 2 '54Dy /3 344 0- 0 152 Gd g.s. Figure 7-11 Comparison offlquasirotational bands for some N= 88 isotones. The 152Gd ground-state band has been included for scale. 158 10 2304 72 183 6 2099 6 ') 2107 5 2020 ) '.' 8 6 5 1990 1862(- 1748 1227 4 1683 4+1643 3 1512 3 2 148 + ) 1886 5' 1740 1504 1550 31434 4i443 3+ 1334 1248 Nd y 1194 150 Sm y152 Gd y 1027 Dyy 4+ 755 2 344 0- 0 ' Gd g.s Figure 7-12 Comparison of ybands for some N = 88 isotones. The '52Gd ground-state band has been included for scale. The bands labeled as "i" are shown for '50Sm '52Gd, and '54Dy in Figure 7-13. The match here is less impressive, though still readily apparent. Mixing with other states as the energy increases is the likely case of the energy differences of excited states in the i bands. 7.5 Conclusions 7.5.1 Summary The improved ability of the 8it spectrometer and other newer multi-detector 159 10 2300 S 1747 2' 1417 - 6 1227 0 15Oc 7c 2 1255 mi 2 \o 2 1390 0 1058 1318,' 1048 "2Gdi Dyi 344 0 152 Gdg.s. Figure 7-13 Comparison of the "i" rotational bands in some N= 88 isotones. The 152Gd ground-state band has been included for scale. arrays to record high-quality coincidence data provides good reason for repeating and the ability to improve upon previous work. The linkage of excited states and the strength of the transitions that connect those states have been clarified beyond presently published data in many cases. 54 new levels are postulated and 266 new transitions have been identified as produced by the '52Gd. Angular correlation of the radiations from more than 250 different cascades has provided spin and parity assignments for many of these levels. Mixing ratios for 144 transitions have been reported. This new information serves as a basis for further model development. The low-energy excited states of '52Gd can be organized into related bands to highlight possible underlying structures. These bands can be described by various models with a range of success. While no model sufficiently explains all bands, the 160 soft-rotor model described the widest range of structures in a qualitative manner. Improvements on the IBM and other quantitative models have been able to describe the some of the transitional behavior of the N = 88 region. The similarity of band structure seen in the N = 88 isotones even within a region of rapid shape change suggests the possibility of a relatively uncomplicated model description that encompasses several nuclei in this region. Newly discovered excited states in 152Gd that are analogous to those in '50Sm, support the development of a common structure description including and extending beyond these nuclei. 7.5.2 Further work Although minor refmements might be made in the level scheme and the spectroscopy, the level energies and transitions listed in this work are complete to an uncertainty that is beyond what is needed to compare the data to current models. Further study of tray energies and level relationships is of limited value. Lifetime measurements of more excited states would be helpful to compare absolute B(E2) values. However, due to the difficulty in obtaining these measurements, coulomb excitation, while still hindered by the complexity of the level scheme is preferred for further measurement of transition strengths. The systematic patterns found in neighboring nuclei may be the foundation of a new type of band description. The 148Nd and '54Dy spectroscopy should be investigated with the higher power of a detector such as the 8it to look for new states and bands similar to the "i" and '' bands in '52Gd. 161 8. Appendix 162 Appendix 1 Energy sorted tray list. Energies are in keV, LI is the initial level, LF is the fmal level populated by a transition. The intensities are normalized so that the 344 keV transition has intensity 1000. Ey Abs I L1 117.2 1.56 ± 0.09 1048.1 158.4 0.59 ± 0.04 1282.4 160.4 0.31 ± 0.03 1475.2 169.5 0.48 ± 0.03 1862.2 175.2 0.78 ± 0.05 930.8 178.6 0.22 ± 0.05 1109.4 195.1 7.99 ± 0.43 1318.6 208.9 0.65 ± 0.05 1318.6 J" Lf J'f 930.8 2+ 1123.4 3- 0+ 4+ 0+ 2+ 2+ 2+ 2+ 2+ 1123.4 1109.4 1314.7 1- 1692.5 3+ 4+ 2+ 755.5 930.8 211.6 0.12 ± 0.03 1643.9 2- 1434.1 218.5 0.29 ± 0.02 1862.2 248.8 1.43 ± 0.09 1941.5 1643.9 1692.5 270.3 9.79 ± 6.87 1318.6 2+ 2+ 2+ 271.2 128.76 ± 6.87 615.5 296.1 <.01 1771.7 297.8 0.13 ± 0.01 1941.5 311.7 0.19 ± 0.01 1862.2 315.2 13.64 ± 0.69 930.8 324.7 0.64 ± 0.05 1434.1 335.6 1.05 ± 0.17 337.6 0+ 2+ 2+ 3- 2+ 3+ 2- 1475.2 3+ 0+ 2+ 0+ 1048.1 344.3 1643.9 2- 1550.2 1941.5 2+ 2+ 3+ 2+ 1605.8 4+ 0+ 2+ 2+ 0.31 ± 0.05 1808.0 (4-) 1470.7 5(-) 344.3 1000.00 ± 0.00 344.3 0.0 351.7 4.41 ± 0.22 1282.4 353.7 0.40 ± 0.02 1109.4 2+ 4+ 2+ 367.8 5.66 ± 0.30 1123.4 3- 755.5 387.7 7.14 ± 0.36 1318.6 930.8 391.1 0.41 ± 0.03 407.0 0.75 ± 0.04 1941.5 2247.0 411.2 63.86 ± 3.20 755.5 428.0 0.38 ± 0.02 1862.2 0+ 2+ 4+ 4+ 2+ 4+ 3+ 2+ 3+ 0+ 2+ 2265.5 1314.7 755.5 1123.4 2(+/-) 2+ 615.5 1109.4 930.8 755.5 441.0 0.64 ± 0.05 1550.2 454.7 0.03 ± 0.02 2719.6 456.8 0.83 ± 0.07 1771.7 471.7 0.31 ± 0.03 1227.1 482.5 0.98 ± 0.05 1605.8 2+ 2+ 2+ 4+ 2+ 0+ 4+ 2+ 2+ 6+ 2+ 490.2 0.29 ± 0.03 1808.0 (4-) 1318.6 490.8 1.31 ± 0.10 2247.0 2+ 1757.1 1- 492.2 0.11 ± 0.01 2300.0 2- 1808.0 (4-) 494.0 2.51 ± 0.13 1109.4 2.51 ± 0.15 1605.8 1109.4 503.6 1.33 ± 0.07 1434.1 2+ 2+ 3+ 615.5 496.4 930.8 0+ 2+ 2+ 520.4 1.27 ± 0.07 1643.9 2- 1123.4 3- 432.6 E0 1048.1 1550.2 1839.9 344.3 1434.1 615.5 1109.4 1- 4+ 3- 163 Appendix 1 Energy Sorted tray list. (Continued) Ey Abs I L J1 527.0 4.18 ± 0.22 1282.4 4+ 755.5 534.4 0.92 ± 0.06 1643.9 2- 1109.4 544.0 3.04 ± 0.17 1862.2 1318.6 547.4 0.83 ± 0.07 1862.2 557.7 0.49 ± 0.03 1839.9 557.9 1.50 ± 0.08 1605.8 563.2 1.02 ± 0.06 1318.6 566.3 0.14 ± 0.08 2247.0 2+ 2+ 3+ 2+ 2+ 2+ 577.7 0.61 ± 0.04 2011.8 2,3+ 1434.1 579.9 0.65 ± 0.04 1862.2 1282.4 586.7 147.00 ± 7.35 595.8 0.10 ± 0.06 2729.3 2+ 2+ 2+ 597.8 0.14 ± 0.02 1915.5 930.8 J 4+ 2+ 2+ 1314.7 1- 1282.4 1605.8 4+ 0+ 4+ 0+ 3+ 4+ 2+ 2+ 2+ 0+ 2+ 4+ 6+ 2+ 2+ 1123.4 3- 1048.1 755.5 1681.1 344.3 2133.6 623.0 14.88 ± 0.77 1941.5 633.5 0.11 ± 0.01 1915.5 633.6 0.03 ± 0.01 1860.8 634.0 0.03 ± 0.01 2880.9 641.5 0.95 ± 0.10 648.5 1.99 ± 0.11 2247.0 1771.7 3+ 0+ 2+ 3+ 5+ 2+ 2+ 2+ 656.4 0.62 ± 0.04 2300.0 2- 1643.9 2- 659.2 0.37 ± 0.02 1941.5 1282.4 662.7 0.22 ± 0.03 1771.7 675.2 9.65 ± 0.49 1605.8 678.8 4.13 ± 0.22 1434.1 2+ 2+ 2+ 3+ 4+ 2+ 2+ 4+ 681.6 <.03 ± 0.01 3012.1 2+,3,4+ 684.3 0.36 ± 0.02 1808.0 (4-) 693.6 0.56 ± 0.04 2011.8 2,3+ 2330.7 1123.4 1318.6 697.2 0.27 ± 0.03 2011.8 2,3+ 698.0 0.11 ± 0.01 2709.7 2+ 615.5 E0 615.5 1318.6 0.0 1318.6 1282.4 1227.1 2247.0 1109.4 930.8 755.5 1314.7 2011.8 615.5 699.6 1.50 ± 0.08 1314.7 1- 703.3 14.71 ± 1.26 1318.6 703.9 25.74 ± 2.21 2+ 0+ 2+ 1692.5 930.8 3,4,5 3- 2+ 1- 2,3+ 709.5 0.78 ± 0.05 2401.8 713.1 2.22 ± 0.12 1643.9 2- 715.3 0.98 ± 0.06 1470.7 5(-) 755.5 0+ 0+ 2+ 3+ 2+ 4+ 721.8 0.06 ± 0.01 2529.6 3(+) 1808.0 (4-) 723.9 0.47 ± 0.04 1771.7 2+ 1048.1 730.8 0.76 ± 0.06 1839.9 1109.4 0+ 2+ 738.9 4.32 ± 0.23 1862.2 747.4 0.12 ± 0.07 2880.9 750.5 0.40 ± 0.03 1681.1 753.0 0.41 ± 0.04 1862.2 3+ 2+ 2+ 0+ 2+ 1048.1 615.5 344.3 1123.4 3- 2133.6 2+ 2+ 2+ 930.8 1109.4 164 Appendix 1 Energy Sorted tray list. (Continued) Ey Abs I 756.8 0.16 ± 0.09 2437.8 762.0 0.21 ± 0.02 1692.5 765.2 47.84 ± 2.40 1109.4 768.1 0.38 ± 0.04 779.1 L Jf 1681.1 0+ 2+ 2+ 2524.1 2+ 3+ 2+ 2+ 1757.1 1- 90.66 ± 4.61 1123.4 3- 344.3 2+ 788.3 0.74 ± 0.06 2103.0 -- 1314.7 1- 792.6 0.51 ± 0.03 1915.5 1123.4 3- 794.9 3.10 ± 0.17 1550.2 755.5 4+ 804.5 0.24 ± 0.02 2719.6 1915.5 806.6 0.40 ± 0.04 1915.5 813.0 3.58 ± 0.21 2247.0 813.9 0.42 ± 0.04 2729.3 814.3 0.65 ± 0.04 1862.2 1048.1 3+ 2+ 3+ 3+ 0+ 818.1 1.35 ± 0.08 1941.5 1123.4 3- 818.9 0.75 ± 0.07 2133.6 1314.7 1- 830.0 0.04 ± 0.03 2999.8 832.3 1.85 ± 0.12 1941.5 930.8 344.3 834.2 0.40 ± 0.03 2749.2 3+ 4+ 2+ 3+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 3+ 837.2 0.32 ± 0.03 2529.6 3(+) 1692.5 837.4 0.09 ± 0.05 3006.5 (3-) 2169.8 2- 839.2 0.05 ± 0.01 2121.1 1282.4 841.2 0.69 ± 0.04 1771.7 850.4 0.33 ± 0.02 1605.8 4+ 2+ 2+ 4+ 2+ 4+ 855.3 0.71 ± 0.07 2169.8 2- 1314.7 1- 857.5 1.00 ± 0.08 2773.1 2+,3 1915.5 1109.4 1434.1 1915.5 2169.8 2- 1109.4 2+ 3+ 3+ 1915.5 930.8 755.5 857.9 0.72 ± 0.08 2719.6 2+ 1862.2 865.8 0.75 ± 0.05 2300.0 2- 1434.1 3+ 2+ 3+ 869.1 0.16 ± 0.02 2+ 2011.8 2,3+ 877.8 0.32 ± 0.02 (4-) 930.8 887.5 0.82 ± 0.09 2880.9 1808.0 2749.2 3+ 1862.2 893.6 12.84 ± 0.66 1941.5 2+ 1048.1 902.7 2.87 ± 0.18 2011.8 2,3+ 1109.4 909.2 2.50 ± 0.13 1839.9 930.8 912.7 0.06 ± 0.02 1668.2 914.6 1.07 ± 0.07 2558.1 928.6 5.46 ± 0.29 2247.0 930.2 23.36 ± 0.47 930.8 931.5 1.68 ± 0.10 1862.2 932.1 3.50 ± 0.24 2247.0 937.3 2.96 ± 0.16 1692.5 3+ 6+ 2+ 2+ 2+ 2+ 2+ 3+ 2+ 2+ 0+ 2+ 2+ 4+ 940.3 0.56 ± 0.05 2258.2 -- 952.5 0.70 ± 0.06 2265.5 2(+I-) 953.6 0.77 ± 0.06 2709.7 2+ 965.6 1.18 ± 0.09 2880.9 2+ 755.5 1643.9 2- 1318.6 2+ 0+ 2+ 0.0 930.8 1314.7 1- 755.5 1318.6 4+ 2+ 1314.7 1- 1757.1 1- 1915.5 3+ 165 Appendix 1 Energy Sorted ray list. (Continued) E' Abs I L J'j Jf 970.5 13.29 ± 0.68 1314.7 1- 344.3 974.3 52.15 ± 2.63 1318.6 2+ 344.3 2+ 2+ 3+ 4+ 975.1 0.75 ± 0.06 2667.7 l+,2+ 1692.5 979.6 1.22 ± 0.06 2529.6 3(+) 1550.2 985.3 1.07 ± 0.09 2300.0 2- 1314.7 1- 990.4 13.50 ± 0.69 1605.8 2+ 615.5 1605.8 0+ 2+ 2+ 3+ 4+ 3+ 993.3 0.91 ± 0.10 2599.0 (2+) 1010.8 6.77 ± 0.35 1941.5 1013.0 0.49 ± 0.04 2928.1 1016.1 0.98 ± 0.06 1771.7 1017.2 0.85 ± 0.06 2709.7 2+ 2+ 2+ 2+ 930.8 1915.5 755.5 1692.5 1021.6 0.64 ± 0.04 3309.7 2+,3,4+ 2287.8 -- 1027.3 0.18 ± 0.02 2719.6 2+ 1692.5 3+ 1029.4 0.24 ± 0.02 2500.1 3-,4,5 1470.7 5(-) 1031.3 0.37 ± 0.03 1962.1 -- 930.8 1036.9 2.04 ± 0.13 2729.3 1692.5 1048.1 2+ 0+ 2964.1 3(+) 1915.5 755.5 2+ 3+ 0+ 3+ 4+ 3+ 1048.1 1048.7 E0 0.51 ± 0.05 0.0 1052.4 1.99 ± 0.11 1808.0 (4-) 1057.0 0.42 ± 0.03 2749.2 0.13 ± 0.01 2709.7 3+ 2+ 1692.5 1066.3 1643.9 2- 1069.4 1069.6 0.53 ± 0.04 2503.6 2+,3,4+ 1434.1 3+ 0.35 ± 0.03 2193.3 -- 1123.4 3- 1072.7 0.10 ± 0.01 2387.3 1-,2-3- 1314.7 1- 1076.2 0.58 ± 0.04 2719.6 2+ 1643.9 2- 1081.4 0.20 ± 0.02 2011.8 2,3+ 930.8 1083.8 0.16 ± 0.02 2401.8 2+ 1318.6 1084.1 0.70 ± 0.05 0.82 ± 0.05 2.12 ± 0.14 1643.9 2- 1086.9 2.39 ± 0.21 2401.8 1314.7 1- 1089.8 15.73 ± 0.88 1434.1 3+ 2+ 2+ 3+ 1109.4 755.5 1085.9 2193.3 1839.9 2729.3 -- 1084.3 2+ 2+ 2+ 4+ 344.3 1090.9 0.33 ± 0.03 3006.5 (3-) 1915.5 1109.4 2+ 3+ 2+ 4+ 0+ 3+ 1092.7 0.77 ± 0.07 1106.6 5.66 ± 0.30 2201.8 1862.2 1109.3 43.16 ± 2.18 1109.4 2+ 2+ 2+ 1117.3 0.46 ± 0.03 2551.5 -- 1434.1 1123.5 1.24 ± 0.08 2247.0 2+ 1123.4 3- 1126.9 0.39 ± 0.03 3042.3 (2+) 1915.5 3+ 1128.9 0.70 ± 0.06 2773.1 2+,3 1643.9 2- 1131 .0 2.39 ± 0.14 1475.2 344.3 1137.9 13.77 ± 0.85 2247.0 0+ 2+ 1109.4 2+ 2+ 1142.2 0.55 ± 0.04 2265.5 2(+I-) 1123.4 3- 1149.1 0.80 ± 0.06 2258.2 1109.4 2+ 755.5 0.0 166 Appendix 1 Energy Sorted tray list. (Continued) E'y 1155.5 1159.9 1164.1 1165.0 1168.3 1171.9 1176.5 1185.9 1188.2 Abs I 0.24 ± 0.02 4.40 ± 0.23 0.19 ± 0.03 0.20 ± 0.02 0.62 ± 0.19 0.95 ± 0.05 0.25 ± 0.02 3.60 ± 0.19 0.60 ± 0.05 1190.5 6.88 ± 0.40 1191.7 1199.4 1201.9 1203.0 1203,9 1205.5 0.16 ± 0.02 0.15 ± 0.02 1209.1 1218.2 1219.4 4.87 ± 0.32 1222.0 1235.5 1237.3 1246.7 1247.2 1253.1 1257.4 1261.4 1262.5 1263.8 1271.6 1275.2 1275.7 1278.2 1284.5 1289.3 1299.2 1307.8 1314.5 1314.7 1316.2 1318.6 1325.9 1327.3 0.36 ± 0.08 0.54 ± 0.04 0.60 ± 0.05 1.79 ± 0.11 0.27 ± 0.03 0.13 ± 0.02 0.32 0.77 0.26 0.38 2.24 0.35 0.53 15.54 0.39 1.35 0.23 1.27 0.32 0.53 1.34 0.33 33.84 ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± 0.03 0.06 0.02 0.03 0.14 0.03 0.04 0.79 0.03 0.08 0.02 0.13 0.03 0.04 0.09 0.05 1.69 0.03 ± 0.01 1.27 ± 0.08 22.66 ± 1.13 4.41 ± 0.23 4.86 ± 0.39 14.14 ± 0.72 0.78 ± 0.08 L1 2437.8 1915.5 3080.3 2599.0 3009.4 2928.1 2300.0 1941.5 2880.9 2300.0 2882.9 3006.5 2325.8 2133.6 2327.6 1550.2 2524.1 2327.6 1975.8 2540.3 2928.1 2880.9 1862.2 2529.6 3009.4 2691.8 1605.8 2193.3 2387.3 2201.8 2880.9 2709.7 2401.8 2928.1 2604.4 1643.9 3066.5 2437.8 1314.7 2247.0 1318.6 1941.5 2642.0 J" L 1282.4 755.5 2+,3,4+ 1915.5 (2+) 1434.1 (2+) 1839.9 2+ 1757.1 21123.4 2+ 755.5 2+ 1692.5 21109.4 2+ 1692.5 (3-) 1808.0 I 1123.4 2+ 930.8 2,3+ 1123.4 4+ 344.3 2+ 1314.7 2,3+ 1109.4 2+ 755.5 3+ 1318.6 2+ 1692.5 2+ 1643.9 2+ 615.5 3(+) 1282.4 (2+) 1757.1 1+,2+ 1434.1 2+ 344.3 -930.8 1-,2-3- 1123.4 2+ 930.8 2+ 1605.8 2+ 1434.1 2+ 1123.4 2+ 1643.9 2(-) 1314.7 344.3 22,3 1757.1 2+ 1123.4 10.0 2+ 930.8 2+ 0.0 2+ 615.5 2,31314.7 2+ 3+ J'tf 4+ 4+ 3+ 3+ 3+ 1- 3- 4+ 3+ 2+ 3+ (4-) 32+ 32+ 1- 2+ 4+ 2+ 3+ 20+ 4+ 1- 3+ 2+ 2+ 32+ 2+ 3+ 321- 2+ 130+ 2+ 0+ 0+ 1- 167 Appendix I Energy Sorted ray list. (Continued) Ey Abs I L 'it 1331.2 1336.8 1338.4 1344.0 0.07 ± 0.01 2.27 ± 0.12 0.34 ± 0.03 0.32 ± 0.03 0.11 ± 0.01 15.33 ± 0.77 0.79 ± 0.08 0.58 ± 0.03 0.07 ± 0.08 0.76 ± 0.06 1.64 ± 0.10 2.31 ± 0.13 1.22 ± 0.08 0.16 ± 0.01 0.75 ± 0.09 0.15 ± 0.05 1.95 ± 0.12 3139.8 2+ 0+ 2+,3 1-,2 1347.1 1348.2 1352.9 1360.3 1364.1 1364.2 1365.6 1369.1 1372.0 1378.1 1394.1 1395.4 1400.6 1400.7 1406.4 1410.8 1412.9 1414.3 1417.5 1421.1 1424.6 1427.0 1430.9 1434.9 1437.1 1442.1 1446.4 1446.7 1454.2 1457.6 1470.9 1481.2 1484.5 1486.3 1489.4 1491.5 1495.4 1502.9 1507.0 3.31 ± 0.19 1.78 ± 0.10 4.39 0.24 7.11 ± 0.36 0.64 ± 0.06 0.38 ± 0.04 0.88 ± 0.06 0.19 ± 0.03 1.78 ± 0.11 1.46 ± 0.09 0.43 ± 0.04 0.78 ± 0.09 1.58 ± 0.12 1.05 ± 0.06 3.48 ± 0.20 0.46 ± 0.03 0.08 ± 0.04 0.23 ± 0.02 1.13 ± 0.07 0.10 ± 0.01 0.27 ± 0.02 1.10 ± 0.09 0.38 ± 0.03 1.72 ± 0.10 0.45 ± 0.03 0.84 ± 0.06 ± 1681.1 2773.1 3285.2 3153.2 1692.5 2667.7 1975.8 3009.4 2914.2 2121.1 2300.0 2495.2 2133.6 2999.8 2325.8 L Jf 1808.0 344.3 1434.1 1941.5 1808.0 (4-) 2+ 3+ 2+ (4-) 2+,3,4+ 3+ 344.3 1+,2+ 1314.7 2+ 615.5 (2+) 1643.9 2+ 1550.2 4+ 755.5 2930.8 1-,2 1123.4 2+ 755.5 2+ 1605.8 I 930.8 2524.1 2719.6 2+ 1123.4 1318.6 2529.6 2729.3 3(+) 2+ 1757.1 2964.1 2540.3 2544.6 3340.8 1771.7 2749.2 2558.1 3042.3 3(+) 3+ (2+) (2+) 2+ 3+ 2+ (2+) 2551.5 2201.8 2880.9 2773.1 2387.3 2401.8 2604.4 3400.9 2919.9 2599.0 2247.0 1839.9 2258.2 2437.8 2+ 1- -2+ 2+ 2+,3 1-,2-32+ 2(-) 2+,3 2,3(2+) 2+ 3+ 2+ 1123.4 1318.6 344.3 1550.2 1123.4 1123.4 1915.5 344.3 1318.6 1123.4 1605.8 1109.4 755.5 1434.1 1318.6 930.8 930.8 1123.4 1915.5 1434.1 1109.4 755.5 344.3 755.5 930.8 2+ 1- 0+ 24+ 4+ 2+ 34+ 2+ 2+ 32+ 32+ 2+ 4+ 333+ 2+ 2+ 3- 2 2+ 4+ 3+ 2+ 2+ 2+ 33+ 3+ 2+ 4+ 2+ 4+ 2+ 168 Appendix 1 Energy Sorted tray list. (Continued) Ey 1517.8 1518.2 1518.6 1521.2 1528.9 1530.3 1532.4 1536.0 1544.3 1544.3 1548.0 1554.8 1562.5 1564.7 1566.2 1570.8 1571.1 1575.2 1582.1 1586.3 1593.2 1596.5 1596.9 1599.0 1605.7 1605.8 1606.0 1609.1 1613.3 1613.5 1620.7 1631.5 1631.5 1633.5 1640.1 1642.4 1645.2 1646.1 1646.3 1646.5 1663.4 1667.5 Abs I 7.78 ± 0.43 0.37 ± 0.02 2.03 ± 0.11 0.36 ± 0.04 0.12 ± 0.02 0.14 ± 0.02 0.39 ± 0.03 0.28 ± 0.02 0.18 ± 0.02 0.60 ± 0.04 0.56 ± 0.06 0.09 ± 0.01 1.06 ± 0.07 0.31 ± 0.03 1.60 ± 0.12 0.24 ± 0.02 2.67 ± 0.14 1.05 ± 0.06 1.09 ± 0.10 16.81 ± 0.89 1.38 ± 0.09 3.28 ± 0.18 6.30 ± 0.35 4.30 ± 0.24 0.23 ± 0.04 3.31 ± 0.17 2.69 ± 0.15 0.10 ± 0.02 0.46 ± 0.03 0.35 ± 0.03 0.24 ± 0.02 2.73 ± 0.14 1.13 ± 0.06 0.40 ± 0.05 0.94 ± 0.08 0.20 ± 0.02 0.31 ± 0.04 0.62 ± 0.05 0.39 ± 0.03 0.14 ± 0.02 0.49 ± 0.07 11.24 ± 0.60 L1 1862.2 2133.6 2642.0 3212.9 3285.2 2964.1 2287.8 2291.5 3236.5 2667.7 2862.6 2169.8 2880.9 2495.2 2880.9 2325.8 1915.5 2330.7 2691.8 2709.7 2524.1 2719.6 1941.5 2529.6 2919.9 1605.8 2729.3 2540.3 2544.6 J 2+ 2+ 2,31+,2+ 1-,2 3(+) --- 2+ 1+,2+ 2,322+ 1-,2 2 I 3+ 3,4,5 1+,2+ 2+ 2 2+ 2+ 3(+) 2,32+ 2+ 3+ (2+) 3047.1 1+,2,3- 2551.5 2247.0 1975.8 2742.4 2749.2 3335.3 3400.9 2964.1 3080.3 2401.8 -2+ 2+ -3+ 2773.1 2011.8 2+,3,4+ 2+,3 3(+) 2+,3,4+ 2+ 2+,3 2,3+ L Jf 344.3 615.5 2+ 0+ 1123.4 3- 1692.5 1757.1 1434.1 755.5 755.5 1692.5 1123.4 1314.7 615.5 1318.6 930.8 1314.7 755.5 344.3 755.5 1109.4 1123.4 930.8 1123.4 344.3 930.8 1314.7 0.0 1123.4 930.8 930.8 1434.1 930.8 615.5 344.3 1109.4 1109.4 1692.5 1757.1 1318.6 1434.1 755.5 1109.4 344.3 3+ 13+ 4+ 4+ 3+ 31- 0+ 2+ 2+ 1- 4+ 2+ 4+ 2+ 32+ 32+ 2+ 1- 0+ 32+ 2+ 3+ 2+ 0+ 2+ 2+ 2+ 3+ 1- 2+ 3+ 4+ 2+ 2+ 169 Appendix 1 Energy Sorted tray list. (Continued) Ey Abs I L1 J1 1668.1 1681.6 1682.3 1684.8 1690.2 0.33 ± 0.03 0.48 ± 0.04 0.20 ± 0.02 0.27 ± 0.05 0.44 ± 0.07 0.51 ± 0.06 0.31 ± 0.06 0.30 ± 0.03 1.25 ± 0.16 0.15 ± 0.01 0.45 ± 0.07 0.80 ± 0.06 1.58 ± 0.09 0.12 ± 0.01 2599.0 2729.3 2964.1 2999.8 3006.5 3009.4 3009.4 (2+) 2+ 3(+) 2+ (3-) (2+) (2+) 2,3- 1690.6 1694.5 1711.2 1727.4 1729.7 1732.3 1736.9 1739.5 1748.4 1757.5 1757.5 1758.2 1761.7 1769.3 1771.5 1772.1 1779.0 1784.7 1785.2 1786.8 1789.1 1789.3 1790.7 1792.5 1797.0 1798.5 1802.5 1805.2 1807.1 1809.5 1810.5 1812.6 1818.7 1821.5 1825.4 1836.0 1841.0 1841.8 1845.2 11.21 ± 0.61 0.21 ± 0.03 0.27 ± 0.03 0.71 ± 0.07 0.10 ± 0.01 5.34 ± 0.33 0.30 ± 0.24 1.56 ± 0.09 0.79 ± 0.05 0.20 ± 0.02 0.21 ± 0.02 1.31 ± 0.08 7.24 ± 0.37 0.18 ± 0.02 1.17 ± 0.08 1.22 ± 0.07 1.79 ± 0.10 1.15 ± 0.07 0.09 ± 0.01 0.11 ± 0.01 1.28 ± 0.07 0.38 ± 0.04 0.16 ± 0.02 0.90 ± 0.07 0.09 ± 0.01 2.15 ± 0.12 0.00 ± 0.00 0.97 ± 0.06 0.56 ± 0.05 0.22 ± 0.04 2642.0 3042.3 2345.2 3047.1 2667.7 2862.6 2503.6 2880.9 2687.1 J1tf 930.8 1048.1 1282.4 1314.7 1314.7 1318.6 1314.7 930.8 2+ 0+ 4+ 11- 2+ 12+ (2) 1- 1,2+ 1+,2,3- 0+ 1314.7 615.5 1314.7 1+,2 930.8 2,31123.4 2+,3,4+ 755.5 2+ 1123.4 1,2+ 930.8 3400.9 2+,3 3080.3 2524.1 2880.9 3205.8 2709.7 2540.3 3335.3 2401.8 2719.6 2133.6 2544.6 2901.9 2919.9 2729.3 2558.1 2853.3 3499.6 2932.6 2919.9 2742.4 2+,3,4+ 1318.6 755.5 1109.4 1434.1 930.8 755.5 2+,3,4+ 1550.2 2+ 615.5 2+ 930.8 2+ 344.3 (2+) 755.5 -1109.4 2,31123.4 2+ 930.8 2+ 755.5 1,2+ 1048.1 2+,31692.5 2+ 1123.4 2,31109.4 930.8 2928.1 2437.8 2169.8 2946.7 2964.1 2773.1 2776.4 2+ 2+ 2-3(+) 2+,3 2+,3,4+ 1643.9 2+ 2+ 2+ 2+ 3+ 1109.4 615.5 344.3 1109.4 1123.4 930.8 930.8 1- 2+ 34+ 32+ 22+ 4+ 2+ 3+ 2+ 4 4+ 0+ 2+ 2+ 4+ 2+ 32+ 4+ 0+ 3 32+ 2+ 2+ 0+ 2+ 2+ 32+ 2+ 170 Appendix 1 Energy Sorted tray list. (Continued) Ey 1857.5 1862.3 1870.9 1875.1 1876.4 1886.4 1890.4 1894.3 1896.9 1897.1 1901.9 1902.6 1908.4 1913.2 1916.1 1918.0 1921.1 1928.9 1932.2 1933.2 1941.3 1950.1 1951.5 1954.0 1955.8 1956.8 1965.5 1970.4 1970.8 1974.0 1975.8 1983.5 1993.8 1996.0 2004.1 2012.2 2015.3 2018.1 2021.4 2021.9 2033.9 2043.1 2043.8 Absi L1 2.79 ± 0.15 6.83 ± 0.39 0.21 ± 0.02 0.25 ± 0.04 0.23 ± 0.02 0.65 ± 0.05 0.40 ± 0.05 0.38 ± 0.03 0.25 ± 0.04 0.41 ± 0.06 0.49 ± 0.06 28.27 ± 1.43 0.26 ± 0.02 0.98 ± 0.06 0.31 ± 0.04 0.40 ± 0.05 6.68 ± 0.34 0.24 ± 0.02 0.09 ± 0.02 0.62 ± 0.07 11.60 ± 0.58 0.20 ± 0.03 0.21 ± 0.03 0.14 ± 0.03 5.00 ± 0.27 0.23 ± 0.02 0.27 ± 0.03 0.73 ± 0.08 0.13 ± 0.02 0.07 ± 0.01 1.13 ± 0.06 1.46 ± 0.09 1.75 ± 0.10 0.08 ± 0.01 0.13 ± 0.03 0.35 ± 0.11 0.30 ± 0.02 0.46 ± 0.04 0.14 ± 0.03 0.09 ± 0.01 2.59 ± 0.15 1.15 ± 0.07 0.41 ± 0.05 2201.8 1862.2 2+ 2+ 3153.2 2+,3,4+ 3189.7 2999.8 3009.4 2999.8 3212.9 3212.9 3006.5 2+ (2+) 2+ 1+,2+ 1+,2+ (3-) 3012.1 2247.0 2524.1 2+,3,4+ 2258.2 3025.3 3233.0 2265.5 2544.6 2862.6 3042.3 1941.5 2880.9 3265.5 2882.9 2300.0 3080.3 3088.3 3285.2 2901.9 2729.3 1975.8 2327.6 2749.2 -2+,3,4+ 2928.1 2347.8 3325.2 2946.7 2773.1 2776.4 3340.8 2964.1 2387.3 3153.2 2+ 2+ 2+32(+I-) (2+) 2,3(2+) 2+ 2+ 1-,2,32+ 22+,3,4+ (2+) 1-,2 -2+ 2+ 2,3+ 3+ 2+ 1,2+ 2+ -2+,3 2+,3,4+ (2+) 3(+) 1-,2-32+,3,4+ L Jf 344.3 0.0 1282.4 1314.7 1123.4 1123.4 1109.4 1318.6 1314.7 1109.4 1109.4 344.3 615.5 344.3 1109.4 1314.7 344.3 615.5 930.8 1109.4 0.0 930.8 1314.7 930.8 344.3 1123.4 1123.4 1314.7 930.8 755.5 0.0 344.3 755.5 930.8 344.3 1314.7 930.8 755.5 755.5 1318.6 930.8 344.3 1109.4 2+ 0+ 4+ 1- 332+ 2+ 1- 2+ 2+ 2+ 0+ 2+ 2+ 1- 2+ 0+ 2+ 2+ 0+ 2+ 1- 2+ 2+ 331- 2+ 4+ 0+ 2+ 4+ 2+ 2 1- 2+ 4+ 4+ 2+ 2+ 2+ 2+ 171 Appendix 1 Energy Sorted tray list. (Continued) Ey 2044.2 2050.9 2051.9 2058.2 2059.2 2069.1 2075.5 2076.0 2078.8 2086.5 2092.7 2093.5 2094.0 2102.8 2104.1 2108.4 2111.7 2113.6 2118.6 2127.3 2128.2 2128.7 2140.3 2150.2 2150.9 2158.8 2161.7 2168.6 2168.9 2172.1 2176.0 2177.0 2180.0 2181.7 2181.9 2184.8 2185.0 2190.9 2195.9 2201.4 2201.8 2208.5 2209.1 Abs) 0.34 ± 0.07 0.37 ± 0.03 0.13 ± 0.01 0.23 ± 0.03 0.10 ± 0.01 1.58 ± 0.09 0.57 ± 0.08 0.74 ± 0.05 1.40 ± 0.10 0.42 ± 0.05 0.15 ± 0.02 1.90 ± 0.10 1.34 ± 0.09 0.31 ± 0.04 0.47 ± 0.03 0.20 ± 0.02 0.25 ± 0.05 1.51 ± 0.10 0.90 ± 0.06 0.14 ± 0.02 0.32 ± 0.04 0.30 ± 0.02 0.15 ± 0.02 0.34 ± 0.03 3.95 ± 0.23 1.34 ± 0.08 0.57 ± 0.04 0.59 ± 0.04 0.54 ± 0.06 0.59 ± 0.04 0.28 ± 0.04 0.45 ± 0.03 1.15 ± 0.18 0.28 ± 0.03 0.29 ± 0.03 0.29 ± 0.04 4.07 ± 0.25 0.42 ± 0.04 1.36 ± 0.12 0.22 ± 0.01 0.22 ± 0.02 0.30 ± 0.03 0.22 ± 0.02 L1 3359.3 2981.5 2667.7 2401.8 3182.5 2999.8 3006.5 2691.8 3009.4 2430.7 3139.8 2437.8 2709.7 3212.9 2719.6 3233.0 3042.3 2729.3 2734.3 3250.9 3236.5 2882.9 3265.5 3080.3 2495.2 2914.2 3285.2 3098.9 2513.3 2928.1 3285.2 2932.6 2524.1 3112.5 3305.3 3499.6 2529.6 3314.7 2540.3 2201.8 3132.4 3139.8 2964.1 L Jf 1314.7 1- 2+,3,4+ 930.8 1+,2+ 615.5 2+ 344.3 2+,3,4+ 1123.4 2+ 930.8 (3-) 930.8 1+,2+ 615.5 (2+) 930.8 2+ 0+ 2+ 32+ 2+ 0+ 2+ 1-,2,3- -- 344.3 2+ 2+ 2+ 1048.1 2+ 0+ 344.3 615.5 1109.4 2+ 0+ 2+ 2+ 2+,3(2+) 615.5 1123.4 2+ 1+ 615.5 0+ 32+ 0+ 615.5 1123.4 0+ 3- 1,2+ 2+,3,4+ 930.8 1109.4 2+ 755.5 1-,2,3- 1123.4 2+,3,4+ 930.8 1-,2 344.3 2+ 755.5 1-,2 1123.4 2+,3+ 930.8 4+ 3- 344.3 2+ 2+ 2+ 2+ 2+ 4+ 32+ 1,2+ 2+ 1-,2 755.5 4+ 1109.4 2+ 2+ 2+ 1.2+ 755.5 344.3 930.8 4+ 2+ 2+ 3- -- 1123.4 2+,3- 1314.7 1- 3(+) -3+ 2+ -- 344.3 1123.4 2+ 32+ 0+ 2+ 2+ 4+ 2+ 3(+) 344.3 0.0 930.8 930.8 755.5 172 Appendix 1 Energy Sorted tray list. (Continued) Ey Abs I L. L Jf 2211.7 0.21 ± 0.03 3335.3 2+,3,4+ 1123.4 3- 2213.2 0.17 ± 0.02 3143.8 2+, 3,4+ 930.8 2+ 3- 2217.4 0.93 ± 0.06 3340.8 (2+) 1123.4 2220.9 0.21 ± 0.03 3534.9 2+ 1314.7 1- 2223.4 0.10 ± 0.01 3153.2 2+,3,4+ 2225.9 2233.4 0.35 ± 0.02 2981.5 2+,3,4+ 930.8 755.5 0.09 ± 0.01 3164.8 2236.1 0.21 ± 0.02 2580.4 -- 344.3 2+ 4+ 2+ 2+ 2236.2 0.16 ± 0.02 3359.3 1-,2,3- 1123.4 3- 2246.4 0.33 ± 0.03 2247.0 2+ 0.0 0+ 4+ 2+ 2+ 4+ 2+ 2+ 930.8 2251.2 1.22 ± 0.09 3006.5 (3-) 755.5 2251.6 0.12 ± 0.02 3182.5 2+,3,4+ 930.8 2254.7 1.78 ± 0.14 2599.0 (2+) 344.3 2256.6 0.28 ± 0.02 3012.1 2+,3,4+ 755.5 2259.6 2259.9 0.18 ± 0.03 3189.7 1.15 ± 0.08 2604.4 2(-) 344.3 2262.4 0.25 ± 0.03 3386.4 2+2,4+ 2265.1 1.21 ± 0.08 2880.9 2+ 1123.4 615.5 2270.0 2275.4 0.09 ± 0.01 3025.3 2+,3,4+ 0.20 ± 0.03 3205.8 2+ 755.5 930.8 2276.7 0.35 ± 0.03 3400.9 2+,3 1123.4 3- 2281.3 0.29 ± 0.04 3212.9 1+,2+ 930.8 2298.8 0.26 ± 0.02 2914.2 0.58 ± 0.07 3236.5 2+ 2+ 615.5 2306.0 2306.5 0.04 ± 0.01 2923.8 1,2+ 2311.5 2313.0 0.33 ± 0.03 3066.5 2+,3 0.03 ± 0.01 2928.1 2317.5 0.17 ± 0.02 2932.6 2+ 2+ 2320.1 0.07 ± 0.02 3250.9 2+,3,4+ 930.8 2324.4 2327.2 0.32 ± 0.03 24,3,4+ 0.06 ± 0.01 3080.3 3450.0 24,3,4 755.5 1123.4 2+ 0+ 2+ 0+ 4+ 0+ 0+ 2+ 4+ 2334.0 0.10 ± 0.01 3088.3 (2+) 755.5 2335.0 0.14 ± 0.02 3265.5 1-,2,3- 930.8 2342.5 2.28 ± 0.12 2687.1 1,2+ 344.3 2347.7 0.86 ± 0.05 2347.8 1,2+ 0.0 2348.5 2350.0 0.74 ± 0.05 2691.8 1,2+ 344.3 0.20 ± 0.02 3106.6 2+ 755.5 2354.3 0.38 ± 0.05 3285.2 1-,2 930.8 2360.3 0.29 ± 0.03 3484.1 2+,3,4+ 1123.4 3- 2365.1 7.44 ± 0.39 2709.7 2+ 344.3 2367.5 0.09 ± 0.01 3122.6 2+,3,4+ 755.5 2375.2 14.32 ± 0.75 2719.6 2+ 344.3 2+ 4+ 2+ 2376.3 0.39 ± 0.04 3499.6 2+,3- 1123.4 3- 930.8 930.8 615.5 755.5 615.5 615.5 3- 0+ 4+ 2+ 3- 4+ 2+ 2+ 0+ 2+ 4+ 2+ 173 Appendix 1 Energy Sorted ray list. (Continued) Ey 2378.7 2382.4 2384.3 2388.8 2397.2 2397.8 2404.8 2405.0 2411.9 2420.1 2426.0 2426.9 2428.5 2429.9 2436.3 2440.9 2449.9 2462.7 2471.9 2479.0 2482.2 2488.8 2495.4 2495.7 2497.0 2513.8 2518.2 2524.4 2525.1 2536.3 2551.1 2554.9 2557.7 2569.9 2570.8 2572.2 2575.1 2579.5 2583.9 2585.2 2588.2 2596.9 2598.9 Abs I 0.05 ± 0.02 0.36 ± 0.04 2.15 ± 0.12 0.32 ± 0.03 0.32 ± 0.03 1.42 ± 0.09 23.38 ± 1.22 0.22 ± 0.04 0.27 ± 0.03 0.25 ± 0.05 0.22 ± 0.04 0.19 ± 0.02 0.19 ± 0.03 0.64 ± 0.11 0.14 ± 0.02 0.11 ± 0.02 0.14 ± 0.02 0.16 ± 0.03 0.10 ± 0.01 0.26 ± 0.04 0.15 ± 0.03 1.02 ± 0.09 0.50 ± 0.05 0.82 ± 0.04 0.34 ± 0.05 0.08 ± 0.02 4.25 ± 0.27 1.77 ± 0.09 0.48 ± 0.08 5.18 ± 0.31 1.13 ± 0.10 0.23 ± 0.03 0.53 ± 0.03 6.63 ± 0.35 0.09 0.30 ± 0.01 ± 0.03 1.26 ± 0.11 1.31 ± 0.13 2.80 ± 0.21 0.55 ± 0.04 6.62 ± 0.34 0.33 ± 0.05 0.42 ± 0.03 L1 3134.6 3139.8 2729.3 3143.8 3153.2 2742.4 2749.2 3335.3 3534.9 3350.9 3534.9 3182.5 3359.3 2773.1 3367.3 3551.2 3205.8 3572.9 3226.3 3233.0 3236.5 2833.1 3250.9 2495.2 3112.5 2513.3 2862.6 2524.1 3139.8 2880.9 2895.4 3309.7 2558.1 2914.2 3325.2 3502.6 2919.9 2923.8 2928.1 3340.8 2932.6 3212.9 2599.0 J' L 2+ 2+ 2+ 755.5 755.5 344.3 755.5 755.5 344.3 344.3 930.8 1123.4 930.8 1109.4 755.5 930.8 344.3 930.8 1109.4 755.5 1109.4 755.5 755.5 755.5 344.3 755.5 0.0 615.5 0.0 344.3 0.0 615.5 344.3 344.3 755.5 0.0 344.3 755.5 930.8 344.3 344.3 344.3 755.5 344.3 615.5 0.0 2+, 3,4+ 2+,3,4+ -3+ 2+,3,4+ 2+ -2+ 2+,3,4+ 1-,2,32+,3 -- 2+,3,4+ 2+ -- 2+,3,4+ 2+,32+ 1,2+ 2+,3,4+ 1-,2 1.2+ 1,2+ 2,32+ 2+ 2+ -- 2+,3,4 2+ 2+ 2+ -- 2,31,2+ 2+ (2+) 2+ 1+,2+ (2+) Jf 4+ 4+ 2+ 4+ 4+ 2+ 2+ 2+ 32+ 2+ 4+ 2+ 2+ 2+ 2+ 4+ 2+ 4+ 4+ 4+ 2+ 4+ 0+ 0+ 0+ 2+ 0+ 0+ 2+ 2+ 4+ 0+ 2+ 4+ 2+ 2+ 2+ 2+ 4+ 2+ 0+ 0+ 174 Appendix 1 Energy Sorted ray list. (Continued) E1 Abs I J1 L1 2602.5 3.20 ± 0.19 2946.7 -- 344.3 2603.8 0.19 ± 0.03 3534.9 2+ 930.8 2608.0 0.09 ± 0.02 3539.0 -- 930.8 2619.1 4.68 ± 0.24 2964.1 3(+) 344.3 2619.3 2629.7 0.06 ± 0.01 3551.2 2+,3,4+ 930.8 2+ 2+ 2+ 2+ 2+ 0.15 ± 0.01 3386.4 2+,2,4+ 755.5 4+ 2635.9 2637.2 0.06 ± 0.01 3567.8 2+,3,4+ 930.8 0.45 ± 0.04 2981.5 2+,3,4+ 344.3 2644.5 0.38 ± 0.03 3400.9 2+,3 755.5 2655.0 0.17 ± 0.01 3269.9 1,2+ 615.5 2655.1 2.33 ± 0.20 2999.8 2+ 344.3 2662.3 3.04 ± 0.39 3006.5 (3-) 344.3 2665.0 2.88 ± 0.62 3009.4 (2+) 344.3 2668.0 2.34 ± 0.29 3012.1 2+,3,4+ 344.3 2681.0 1.68 ± 0.19 3025.3 2+,3,4+ 344.3 755.5 2+ 2+ 4+ 0+ 2+ 2+ 2+ 2+ 2+ 4+ 0+ 4+ 2+ 2+ 0+ 0+ 0+ 2+ 4+ 0+ 0+ 2+ 2+ 4+ 4+ 2+ 2+ 2+ 2+ 4+ 2+ 2+ 4+ 2+ 2+ 4+ L1 2684.1 0.05 ± 0.01 3439.2 2+,3,4+ 2687.9 0.65 ± 0.03 2687.1 1,2+ 0.0 2694.3 0.12 ± 0.01 3450.0 2+,3,4 755.5 2697.8 2702.8 3.80 ± 0.29 1.46 ± 0.11 3042.3 (2+) 3047.1 1+,2,3- 344.3 344.3 2709.9 3.21 ± 0.16 2709.7 2710.7 0.20 ± 0.02 3325.2 615.5 2719.9 5.33 ± 0.27 2719.6 2+ 2+ 2+ 2722.2 2.80 ± 0.22 3066.5 2+,3 344.3 0.0 0.0 2728.9 0.13 ± 0.02 3484.1 2+,3,4+ 755.5 2728.9 0.29 ± 0.02 2729.3 2+ 0.0 2734.4 1.42 ± 0.07 2734.3 1+ 0.0 2740.8 2743.9 0.26 ± 0.11 3085.3 1,2+ 344.3 1.52 ± 0.21 344.3 0.23 ± 0.02 3088.3 3499.6 (2+) 2744.1 2+,3- 755.5 2751.7 0.16 ± 0.02 3508.9 (2+) 755.5 2754.5 1.97 ± 0.24 3098.9 2+,3+ 344.3 2768.3 0.58 ± 0.07 3112.5 1.2+ 344.3 2772.5 2778.2 0.12 ± 0.03 3703.4 -- 930.8 0.51 ± 0.06 3122.6 2+,3,4+ 344.3 2779.8 0.05 ± 0.01 3534.9 2+ 755.5 2787.9 0.46 ± 0.06 3132.4 -- 344.3 2795.5 1.47 ± 0.19 3139.8 2+ 344.3 2796.7 0.17 ± 0.01 3551.2 2+,3,4+ 755.5 2799.2 0.70 ± 0.15 3143.8 2+, 3,4+ 344.3 2808.8 0.89 ± 0.11 3153.2 2+,3,4+ 344.3 2811.9 0.07 ± 0.01 3567.8 2+,3,4+ 755.5 J'tf 175 Appendix 1 Energy Sorted ray list. (Continued) E'y Abs I L J'1 Lf 2820.6 2833.5 2838.2 0.49 ± 0.06 -- 344.3 0.13 ± 0.01 3164.8 2833.1 1,2+ 0.0 0.45 ± 0.06 3182.5 2+,3,4+ 344.3 2844.6 0.16 ± 0.03 3189.7 -- 344.3 2861.1 1.09 ± 0.07 3205.8 2+ 344.3 2869.3 0.74 ± 0.05 3212.9 1+,2+ 344.3 2882.0 2882.5 0.89 ± 0.08 3226.3 2+,3,4+ 344.3 1.90 ± 0.10 2882.9 2+ 0.0 2888.8 0.56 ± 0.06 3233.0 2+,3- 344.3 2892.7 2906.7 2915.1 0.86 ± 0.08 3236.5 2+ 344.3 0.86 ± 0.06 3250.9 2+,3,4+ 344.3 0.25 ± 0.01 2914.2 2+ 0.0 2921.6 0.25 ± 0.03 3265.5 1-,2,3- 344.3 2927.6 2940.9 0.72 ± 0.04 2928.1 2+ 0.0 2.94 ± 0.19 3285.2 1-,2 344.3 2961.0 0.65 ± 0.08 3305.3 -- 344.3 2965.7 2971.2 0.31 ± 0.06 3309.7 2+,3,4+ 344.3 0.22 ± 0.05 3314.7 -- 344.3 2980.5 2995.2 1.35 ± 0.24 3325.2 2+ 344.3 1.62 ± 0.15 3340.8 (2+) 344.3 3001.2 0.40 ± 0.03 2999.8 2+ 0.0 3008.4 3015.3 0.15 ± 0.01 3009.4 (2+) 0.0 0.51 ± 0.05 3359.3 1-,2,3- 344.3 3023.1 0.72 ± 0.13 3367.3 -- 344.3 3042.5 0.84 ± 0.07 3386.4 2+,2,4+ 344.3 3056.6 0.92 ± 0.09 3400.9 2+,3 344.3 3068.7 3085.7 0.44 ± 0.05 3413.1 1,2+ 344.3 0.22 ± 0.04 3085.3 1,2+ 0.0 3088.5 0.09 ± 0.03 3088.3 (2+) 0.0 3094.8 0.27 ± 0.02 3439.2 2+,3,4+ 344.3 3107.1 0.46 ± 0.03 3106.6 3134.9 0.09 ± 0.01 3134.6 2+ 2+ 0.0 3139.9 0.52 ± 0.10 3484.1 2+,3,4+ 344.3 3140.6 3158.3 0.38 ± 0.02 3139.8 2+ 0.0 1.85 ± 0.35 3502.6 -- 344.3 3164.7 3.62 ± 0.61 3508.9 (2+) 344.3 3174.5 1.14 ± 0.19 3518.8 3190.0 0.58 ± 0.12 3534.9 3194.9 0.12 ± 0.05 3539.0 3206.2 0.57 ± 0.03 3205.8 2+ 0.0 3223.6 1.02 ± 0.19 3567.8 2+,3,4i- 344.3 3228.8 0.66 ± 0.13 3572.9 -- 344.3 0.0 344.3 2+ 344.3 344.3 Jf 2+ 0+ 2+ 2+ 2+ 2+ 2+ 0+ 2+ 2+ 2+ 0+ 2+ 0+ 2+ 2+ 2+ 2+ 2+ 2+ 0+ 0+ 2+ 2+ 2+ 2+ 2+ 0+ 0+ 2+ 0+ 0+ 2+ 0+ 2+ 2+ 2+ 2+ 2+ 0+ 2+ 2+ 176 Appendix 1 Energy Sorted Ey Abs I ray list. (Continued) L, J Lf Jf 0.94 ± 0.10 3236.5 2+ 0.0 3245.1 0.09 ± 0.03 3589.4 -- 344.3 3251.8 0.12 ± 0.03 3596.1 -- 344.3 3269.6 0.23 ± 0.02 3269.9 1,2+ 0.0 3276.6 3283.9 3311.5 0.32 ± 0.06 3620.9 -- 344.3 0.23 ± 0.05 3628.1 - 344.3 0.04 ± 0.01 3655.7 -- 344.3 3324.9 0.64 ± 0.04 3325.2 2+ 0.0 3329.0 0.18 ± 0.01 3329.0 1,2+ 0.0 3338.4 0.07 ± 0.01 3340.8 (2+) 0.0 3365.1 0.10 ± 0.02 3709.4 -- 344.3 3381.2 0.07 ± 0.00 3381.2 1,2+ 0.0 3413.4 0.10 ± 0.01 3413.1 1,2+ 0.0 3535.9 3574.6 0.02 ± 0.00 3534.9 2+ 0.0 0.06 ± 0.01 3574.6 1,2+ 0.0 0+ 2+ 2+ 0+ 2+ 2+ 2+ 0+ 0+ 0+ 2+ 0+ 0+ 0+ 0+ 3235.3 177 9. References R.M. Steffen and K. Alder in The Electromagnetic Interaction in Nuclear Spectroscopy, edited by W.D. Hamilton (Amsterdam, Holland: North-Holland Publishing Company, 1975, Ch. 1) 2 K.S.Krane and R.M. Steffen, Phys. Rev. C 2, 724 (1971) K.E.G. Löbner, The Electromagnetic Interaction in Nuclear Spectroscopy edited by W.D. 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