Atomic radiations in nuclear decay
Development of a new code to
incorporate atomic data into ENSDF
T. Kibèdi, B.Q. Lee, A.E. Stuchbery, K.A. Robinson (ANU)
F.G. Kondev (ANL)
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Outline
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Motivation
Radiative and Non-radiative atomic transitions in nuclear decay
Nuclear and atomic data
Existing programs to evaluate atomic radiations
New model based on Monte Carlo approach
Future directions
Background
Kálmán Robertson (ANU) Honours project (2010)
Boon Quan Lee (ANU) Honours project (2012)
2012Le09 Lee et al.,
“Atomic Radiations in the Decay of Medical Radioisotopes: A Physics Perspective”
Comp. Math. Meth. in Medicine, v2012, Article ID 651475, doi:10.1155/2012/651475
2011 NSDD meeting (IAEA)
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Medical applications - Auger electrons
Regaud and Lacassagne (1927)
“The ideal agent for cancer therapy would
consist of heavy elements capable of emitting
radiations of molecular dimensions, which
could be administered to the organism and
selectively fixed in the protoplasm of cells
one seeks to destroy.”
Claudius Regaud
(1870-1940)
Antoine Lacassagne
(1884-1971)
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Medical applications - Auger electrons
Regaud and Lacassagne (1927)
“The ideal agent for cancer therapy would
consist of heavy elements capable of emitting
radiations of molecular dimensions, which
could be administered to the organism and
selectively fixed in the protoplasm of cells
one seeks to destroy.”
Claudius Regaud
(1870-1940)
Antoine Lacassagne
(1884-1971)
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
Targeted tumor therapy
(Courtesy of Thomas Tunningley, ANU).
20th NSDD, Kuwait, 27 – 31 January 2013
Medical applications - Auger electrons
Regaud and Lacassagne (1927)
“The ideal agent for cancer therapy would
consist of heavy elements capable of emitting
radiations of molecular dimensions, which
could be administered to the organism and
selectively fixed in the protoplasm of cells
one seeks to destroy.”
Targeted tumor therapy
Biological effect:
Linear energy transfer LET, keV/mm
electrons
(Courtesy of Thomas Tunningley, ANU).
Kassis, Int. J. of Rad. Biol, 80 (2004) 789
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Medical applications - Auger electrons
Regaud and Lacassagne (1927)
“The ideal agent for cancer therapy would
consist of heavy elements capable of emitting
radiations of molecular dimensions, which
could be administered to the organism and
selectively fixed in the protoplasm of cells
one seeks to destroy.”
Targeted tumor therapy
2011 August, INDC International Nuclear
Data Committee
Technical Meeting on Intermediate-term Nuclear
Data Needs for Medical Applications: Cross
Sections and Decay Data
Ed. by A.L. Nichols, et al., NDC(NDS)-0596
Auger emitters: 67Ga , 71Ge, 77Br,
99mTc, 103Pd, 111In, 123I, 125I, 140Nd,
178Ta, 193Pt, 195mPt, 197Hg
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
(Courtesy of Thomas Tunningley, ANU).
20th NSDD, Kuwait, 27 – 31 January 2013
Atomic radiations - Basic concept
X-ray emission
M
3D M5
4
M3
3P
M2
3S M1
2P
2S
L3
L2
L1
Initial vacancy
1S
K
EX Ka 2  EK  EL2
Ka2 X-ray
1 secondary vacancy
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Atomic radiations - Basic concept
X-ray emission
Auger-electron
M
3D M5
4
M3
3P
M2
3S M1
M5
M4
M3
M2
M1
L3
L2
L1
L3
L2
L1
2P
2S
Initial vacancy
1S
K
Initial vacancy
K
EX Ka 2  EK  EL2
Ka2 X-ray
1 secondary vacancy
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
EK L2 L3  EK  EL2  ELL32
K L2 L3 Auger-electron
2 new secondary vacancies
20th NSDD, Kuwait, 27 – 31 January 2013
Atomic radiations - Basic concept
X-ray emission
Coster-Kronig electron
M
3D M5
4
M3
3P
M2
3S M1
M5
M4
M3
M2
M1
L3
L2
L1
L3
L2
L1
2P
2S
Initial vacancy
Initial vacancy
1S
K
K
EX Ka 2  EK  EL2
Ka2 X-ray
1 secondary vacancy
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
EL1L2 M1  EL1  EL2  EML21
L1 L2 M1 Coster-Kronig transition
2 new secondary vacancies
20th NSDD, Kuwait, 27 – 31 January 2013
Atomic relaxation and vacancy transfer
Vacancy cascade in Xe
O1,2,3
N4,5
N2,3
N1
M4,5
M3
M2
M1
A
A
A
A
A
KC
A
A
A
A
A
A
A
A
L3
L2
L1
 Full relaxation of an initial inner shell
vacancy creates vacancy cascade
involving X-ray (Radiative) and Auger as
well as Coster-Kronig (Non-Radiative)
transitions
 Many possible cascades for a single
initial vacancy
 Typical relaxation time ~10-15 seconds
 Many vacancy cascades following a
single ionisation event!
X
Initial vacancy
K
M.O. Krause, J. Phys. Colloques, 32 (1971) C4-67
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Atomic radiations - Basic concept
Vacancy cascade in Xe
O1,2,3
N4,5
N2,3
N1
M4,5
M3
M2
M1
A
A
A
A
A
KC
A
A
A
A
A
A
A
A
Vacancies on the inner-shell can be
produced by
 electron impact
 photo ionization
 ion-atom collision
 internal conversion
 electron capture
 secondary processes accompanying
b-decay or electron capture
L3
L2
L1
X
K
M.O. Krause, J. Phys. Colloques, 32 (1971) C4-67
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Motivation
 X-ray and Auger electron spectrum is an integral part of the radiations
emitted in nuclear decay
 Atomic radiations are important for applications of radioisotopes
(medical physics, nuclear astrophysics, nuclear engineering)
 ENSDF: atomic radiations are not included
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Atomic transition energies and rates
Basic formulas
For a single initial vacancy on the K-shell following nuclear decay
Number of primary
vacancies
Internal conversion
aK
nK  P 
1  aT
Electron capture
nK  P  PK
X-ray emission
Auger-electron
in an ion
Energy
EX KY  EK  EY
EKXY  EK  EX  EYX
Intensity
I X KY  nK  K
I KXY  nK  aK
for L1 shell I X
L1Y
 nL1  L1
K  aK  1
I L1XY  nK  (aL1  f L1L 2  f L1L3 )
L1  aL1  f L1L 2  f L1L3  1
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Existing calculations
Physical approach
RADAR
DDEP
Eckerman &
Endo
(2007)
Howell
(1992)
Stepanek
(2000)
Pomplun
(2012)
ENSDF
DDEP
ENSDF
ENSDF
ENSDF
ICRP38
HsIcc
RpIcc/BrIcc
RpIcc,
1978 Band
RpIcc
2000 Stepanek
HsIcc,
1971 Dragoun,
1976 Band
Electron Capture
Ratios
1971 Gove &
Martin
1995 Schönfeld
1977 Bambynek
1971 Gove &
Martin,
1970Martin
1971 Gove &
Martin,
1970Martin
1971 Gove &
Martin
Atomic transition
rates
1972 Bambynek,
RADLST
1974 Scofield,
1995 Schönfeld
& Janßen,
2006 Be et al.,
EMISSION
1991 Perkins,
EDISTR04
1979 Chen,
1972/1975
McGuire,
1983 Kassis, 1974
Scofield, 1974
Manson & Kenedy
1991 Perkins
1979 Chen,
1972/1975
McGuire, 1970
Storm & Israel,
1979 Krause
Atomic transition
energies
1970 Bearden &
Burr, Neutral
atom
1977 Larkins,
Semi-empirical
1991 Perkins,
Neutral atom
Z/Z+1 (Auger),
Neutral atom (Xray)
Dirack-Fock
calculation
1991 Desclaux,
Dirack-Fock
calculation
Deterministic
Deterministic
Deterministic
(+++)
Monte Carlo
with charge
neutralization
Monte Carlo
Monte Carlo
Nuclear decay
data
Conversion
coefficients
Vacancy
propagation
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Existing calculations
Auger electron yield per nuclear decay
99mTc
111In
(6.007 h)
(2.805 d)
RADAR
DDEP
Eckerman &
Endo
(2007)
Howell
(1992)
0.122
0.13
4.363
4.0
1.136
1.16
7.215
14.7
123I
(13.22 h)
1.064
1.08
13.71
14.9
125I
(59.4 d)
1.77
1.78
23.0
24.9
0.773
0.614
20.9
36.9
Deterministic
Deterministic
Deterministic
(+++)
Monte Carlo
with charge
neutralization
201Tl
(3.04 d)
Vacancy
propagation
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
Stepanek
(2000)
Pomplun
(2012)
2.5
6.05
6.4
15.3
12.2
Monte Carlo
Monte Carlo
20th NSDD, Kuwait, 27 – 31 January 2013
Existing programs
Common problems / limitations
 In some cases neutral atom binding energies are used for atoms with
vacancies; i.e. for ions
 Single initial vacancy is considered. Secondary vacancies are ignored
 Atomic radiations only from primary vacancies on the K and L shell
 Limited information on sub-shell rates
 Auger electrons below ~1 keV are often omitted
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
BrIccEmis – Monte Carlo approach for
vacancy creation and propagation
 Initial state: neutral isolated atom
 Nuclear structure data: from ENSDF
 Electron capture (EC) rates: Schönfeld (1998Sc28)
 Internal conversion coefficients (ICC): BrIcc (2008Ki07)
 Auger and X-ray transition rates: EADL (1991 Perkins)
Calculated for single vacancies!
 Auger and X-ray transition energies: RAINE (2002Ba85)
Calculated for actual electronic configuration!
 Vacancy creation and relaxation from EC and IC: treated independently
 Ab initio treatment of the vacancy propagation:
 Transition energies and rates evaluated on the spot
 Propagation terminated once the vacancy reached the valence shell
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
BrIccEmis
 Reads the ENSDF file, evaluates absolute decay intensities of EC,
GAMMA, CE and PAIR transitions
 Simulates a large number events: 100k-10M radioactive decays
followed by atomic relaxation
 Electron configurations and binding energies stored in memory (and
saved on disk). New configurations only calculated if needed!
(55Fe: 15 k, 201Tl: 1300k)
 Emitted atomic radiations stored on disk (~Gb files)
 Separate files for X-rays and Auger electrons
 Smaller programs to sort/project energy spectra, produce detailed
reports
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
111In
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
EC – vacancy propagation
20th NSDD, Kuwait, 27 – 31 January 2013
99mTc
atomic radiations
below L-shell BE
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
99mTc
atomic radiations – X-rays
DDEP
BrIccEmis
Ka1
18.3672
4.21E-2
18.421
4.05E-2
Ka2
18.251
2.22E-2
18.302
2.13E-2
Kb
20.677
1.30E-2
20.729
1.18E-2
L
[2.134:3.002]
4.82E-3
2.466
4.72E-3
M
0.263
7.83E-4
N
0.047
8.73E-1
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
99mTc
Auger electrons
BrIccEmis:
 10 M simulated decay events
 455 type of Auger transitions
 1981Ge05: measured Auger electrons
in 1500-2300 eV only
Low energy Auger electrons
2012Le09 Lee et al., Comp. Math. Meth. in Medicine, v2012, Art. ID 651475
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
B.Q. Lee, Honours Thesis, ANU 2012
20th NSDD, Kuwait, 27 – 31 January 2013
99mTc
atomic radiations – Auger
electrons
DDEP
BrIccEmis
KLL
[14.86:15.58]
1.49E-2
15.37
1.48E-2
KLX
[17.43:18.33]
2.79E-3
17.85
5.58E-3
KXY
[19.93:21.00]
2.8E-4
20.27
5.07E-4
2.15E-2
16.15
2.08E-2
K-total
CK LLM
2.08E-2
0.054
CK LLX
0.144
9.48E-3
LMM
2.016
9.02E-2
LMX
2.328
1.41E-2
LXY
2.654
6.07E-4
L-total
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
[1.6:2.9]
1.089E-1
1.765
1.24E-1
20th NSDD, Kuwait, 27 – 31 January 2013
99mTc
atomic radiations – Auger
electrons
DDEP
BrIccEmis
CK MMX
0.104
7.10E-1
MXY
0.170
1.10E+0
Super CK NNN
0.014
5.36E-1
CK NNX
Total yield Auger
electron per nuclear
decay
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
~95%
below 500 eV
0.13
0.012
8.45E-1
3.37
20th NSDD, Kuwait, 27 – 31 January 2013
131mXe
IT – charge state at the end of
atomic relaxation
 Only a handful of measurements
exist for ionization by nuclear decay

131mXe:
F. Pleasonton, A.H. Snell,
Proc. Royal Soc. (London) 241 (1957) 141

37Ar:
A.H. Snell, F. Pleasonton,
Phys. Rev. 100 (1955) 1396
 Good tool to asses the
completeness of the vacancy
propagation
 BrIccEmis: mean value is lower by
~0.7-1.0 charge
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
111In
– experiment vs calculation
E.A. Yakushev, et al., Applied Radiation and Isotopes 62 (2005) 451
• ESCA; FWHM = 4 eV
• Calculations normalized to the strongest experimental line
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
111In
– experiment vs calculation
A. Kovalik, et al., J. of Electron Spect. and Rel. Phen. 105 (1999) 219
• ESCA; FWHM = 7 eV
• Calculated energies are higher
• KL2L3(1D2) energy (eV):
19319.2(14)
Experiment
Kovalik (1999)
19308.1
Semi-empirical
Larkins
(1979La19)
19381
RAINE
(2002Ba85)
DE≈60 eV!
• Multiplet splitting could not be
reproduced in JJ coupling
scheme
• Similar discrepancies have been
seen in other elements (Z=47,
Kawakami, Phys. Lett A121
(1987) 414)
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Breit and other QED contributions
(2002Ga47)
Z=49 (In)
~60 eV
Alternative solution:
Semi empirical corrections,
like Larkins (1977La19) or
Carlson (1977Ca31) used
Gaston et al. Phys. Rev A66 (2002) 062505
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Summary – Program developments
 BrIccEmis: calculation intensive approach (hours to days)
 RelaxData (under development):
 Nuclear decay event (EC or CE) produces a SINGLE INITIAL
vacancy
 Considering a single atomic vacancy the relaxation process
independent what produced the vacancy
 Compile a database of atomic radiation spectra for
 produced by a single initial vacancy on an atomic shell
 Carry out calculations of all elements and shells
 Example: 55Fe EC, 7 shells for Z=25 and 26, calculated in
couple of hours (1 M each shell)
 Replace EADL fixed rates and binding energies from RAINE
with GRASP2k/RATIP calculations
 BrIccRelax (under development): Evaluate primary vacancy
distribution and construct atomic spectra from the data base (20
seconds for 55Fe EC)
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013
Inclusion of atomic relaxation data into
ENSDF
Comment
Notation: from IUPAC
X-rays
Auger electrons
K-L3
K-L1-L2
L
KLL
• International Union of Pure and Applied
Chemistry
• Based on initial and final atomic levels involved
Group sub-shells to reduce number
of transitions
•
•
Summed decay rates
Use the mean transition energy for the group
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
(for L1-M2, … L3-O4) (for K-L1-L1, … K-L3-L3)
But not for K
Ka1 for K-L3
Ka2 for K-L2
Kb for K-M3&K-M2
KLX (X=M1….,N1….)
KXY (X&Y=M1….,N1….)
20th NSDD, Kuwait, 27 – 31 January 2013
Inclusion of atomic relaxation data into
ENSDF
ENSDF coding: TRANSITION=ENERGY [INTENSITY]
99TC
99TC1
99TC2
99TC3
99TC4
99TC5
99TC6
99TC
R
R
R
R
R
R
R
L
XKA1=23.25 [0.451]$ XKA2=23.06 [0.239]$ XKB=26.26 [0.142]$
XL=3.23 [6.90e-2]$ XM=0.424 [0.254]$XN=0.0477 [1.03]$
AKLL=19.23 [0.107]$ AKLX=22.46 [4.39E-2]$ AKXY=25.64 [4.29E-3]$
ALLM=0.032 [4.82E-2]$ ALLX=0.234 [0.132]$ ALMM=2.58 [0.816]$
ALMX=3.06 [0.188]$ ALXY=3.54 [1.13E-2]$ AMMX=0.098 [0.859]$
AMXY=0.308 [2.12]$ ANNN=0.020 [0.538]$ ANNX=0.017 [0.681]$
ANXY=0.054 [0.206]
0
9/2+ Before daughter GS level record
X-rays
Auger
electrons
 Intensity need to be normalised to GAMMA-rays; same
normalisation is valid for both
 Number of entries on the “R” (RELAXATION) records
can automatically generated according to Z
 Detailed spectra (list or figure) of the X-rays and Auger
electrons can be generated and distributed for the user
Tibor Kibèdi, Dep. of Nuclear Physics, Australian National University
20th NSDD, Kuwait, 27 – 31 January 2013