Nuclear Physics at Rare-Isotope
Facilities in North-America
IUPAP WG.9 Symposium 2-3 July, 2010
Bradley M. Sherrill
Michigan State University
Brad Sherrill WG.9 July 2010, Slide 1
Slid 1
The Science of Rare Isotopes
Properties of nuclei (nuclear structure)
– Develop a predictive model of nuclei and their interactions
– Many-body quantum problem: intellectual overlap to mesoscopic
science, quantum dots, atomic clusters, etc.
Nuclear processes in the universe
– Chemical history of the universe, (explosive) nucleo-synthesis
– Properties of neutron stars,
EOS of asymmetric nuclear matter
Tests of fundamental symmetries
– Effects of symmetry violations are
amplified in certain nuclei
Societal applications and benefits
– Bio-medicine, energy, material
sciences, national security
Brad Sherrill WG.9 July 2010, Slide 2
Slid 2
Nuclei matter
• The atomic nucleus is a significant intellectual challenge with three of
nature’s four forces having a significant role. Can we construct a
comprehensive and predictive model of its properties? How do we
relate that model to QCD? Surprises are still likely.
• The properties of nuclei are relevant to other sciences, e.g.,
neutrinoless double-beta decay the rate is related to nuclear matrix
elements
• Wealth of quantum phenomena of interest to related sciences
– Mesoscopic systems
– Simple patterns in complex systems (Symmetry phases)
– Connections to atomic clusters
– Open quantum system
– Nuclear reactions
– Efimov states
–…
Brad Sherrill WG.9 July 2010, Slide 3
Slid 3
Properties of rare isotopes are essential in
determining NN and NNN potentials
• Neutron rich nuclei were key
in determining the isospin
dependence of 3-body forces
and the development of IL-2R
from UIX
S. Pieper
B.Wiringa,
et al.
• New data on exotic nuclei
continues to lead to
refinements in the
interactions, e.g., strength of
NN and NNN interactions
• EFT developments, LQCD
and even computational
power are providing insight
for ab initio theories, but they
need grounding in data
Brad Sherrill WG.9 July 2010, Slide 4
Slid 4
Application of GFMC technique
to reactions of nuclei
• Resonance states in 5He (n+4He)
Nollett, et al, PRL
2007; motivated
by BBN modeling
Brad Sherrill WG.9 July 2010, Slide 5
Slid 5
Theory Road Map: Comprehensive Model of
Nuclear Structure and Reactions
• Theory Road Map – comprehensive
description of the atomic nucleus
– Ab initio models – study of neutron-rich, light
nuclei helps determine the force to use in
models (measurement of sensitive
properties for N=14, 16 nuclei)
– Configuration-interaction theory; study of
shell and effective interactions (study of key
nuclei such as 54Ca, 60Ca, 122Zr)
– The universal energy density functional
(DFT) – determine parameters (broad view
of mass surface, BE(2)s, BE(4)s, fission
barrier surface, etc.)
– The role of the continuum and reactions
and decays of nuclei (halo studies up to A
~100)
• IMPORTANT: Understand and
select the most sensitive
measurements
Energy density functional
Configuration
interaction
Ab initio
Continuum
Relationship to QCD (LQCD)
Brad Sherrill WG.9 July 2010, Slide 6
Slid 6
The Challenge: Understand the
Chemical History of the Universe
• Understanding the chemical history of the universe and what it tells us
about individual stars, the first stars, galactic evolution
• The abundance of elements tell us about the history of events prior to
stellar formation. How can we extract that information?
Solar system abundances
Lodders (2003)
Brad Sherrill WG.9 July 2010, Slide 7
Slid 7
Forefront of Observational Astronomy:
High Resolution Telescopes
• The measurement of elemental abundances is
at the forefront of astronomy using large
telescopes
Hubble
Space
• Large mirrors enable high resolution
spectroscopic studies in a short time (Hubble,
LBT, Keck, …)
• Surveys have provided large data sets (SDSS,
LAMOS, SkyMap, HERMES, LSST, Gaia, …)
Large Binocular Telescope
• Future missions: JWST - “is specifically
designed for discovering and understanding the
formation of the first stars and galaxies,
measuring the geometry of the Universe and the
distribution of dark matter, investigating the
evolution of galaxies and the production of
elements by stars, and the process of star and
planet formation.”
Brad Sherrill WG.9 July 2010, Slide 8
Slid 8
Search for the ashes of the first
stars
• Less Fe implies
earlier star
formation
• Measured with
high resolving
power telescopes,
Hubble, Keck,
LBT, etc.
• The process that
makes Ba must be
different from the
main process that
makes Fe
• The [Ba/Fe]
pattern is not
understood
Logarithmic ratio of
abundances relative the Sun
Brad Sherrill WG.9 July 2010, Slide 9
Slid 9
There are a number of
nucleosynthesis processes
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Big Bang Nucleosynthesis
pp-chain
CNO cycle
Helium, C, O, Ne, Si burning
s-process
r-process
rp-process
νp – process
p – process
α - process
fission recycling
Cosmic ray spallation
pyconuclear fusion
+ others
Green – rare isotopes are necessary
for accurate modeling of this process
Brad Sherrill WG.9 July 2010, Slide 10
Slid 10
Tests of Nature’s Fundamental
Symmetries
• Angular correlations in β-decay and
search for scalar currents
o
o
Mass scale for new particle comparable
with LHC
6He
and 18Ne at 1012/s
• Electric Dipole Moments
o
225Ac, 223Rn, 229Pa
sensitive than
(30,000 more
I > 1010/s)
199Hg;
• Parity Non-Conservation in atoms
o
γ
e
weak charge in the nucleus (francium
isotopes; 109/s)
• Unitarity of CKM matrix
o
Vud by super allowed Fermi decay
o
Probe the validity of nuclear corrections
Z
212Fr
Brad Sherrill WG.9 July 2010, Slide 11
Slid 11
Rare Isotopes For Society
• Isotopes for medical research
– Examples of isotopes projected to have demand much greater than supply: 47Sc, 62Zn,
64Cu, 67Cu, 68Ge, 149Tb, 153Gd, 168Ho, 177Lu, 188Re, 211At, 212Bi, 213Bi, 223Ra (DOE Isotope
Workshop)
– -emitters 149Tb, 211At: potential treatment of metastatic cancer
– Cancer therapy of hypoxic tumors based on 67Cu possible is a source would be available
• Nuclear power (nuclear data is needed to optimize reactor design)
• Reaction rates important for stockpile stewardship and nuclear power –
related to astrophysics network calculations
– Determination of extremely high neutron fluxes by activation analysis
– Rare isotope samples for (n,g), (n,n’), (n,2n), (n,f) e.g. 88,89Zr
» Same technique important for astrophysics
– More difficult cases studied via surrogate reactions (d,p), (3He, xn) …
• Tracers for Geology (32Si), Condensed Matter (8Li), material studies, …
• Special isotopes for homeland security applications (β-delayed neutron
emitters to calibrate detectors, etc.)
Brad Sherrill WG.9 July 2010, Slide 12
Slid 12
The availability of rare isotopes
over time
Nuclear
Chart in 1966
Less than 1000
known isotopes
about 3000
known isotopes
New territory to be explored
with next-generation RIB
facilities
Brad Sherrill WG.9 July 2010, Slide 13
Slid 13
What New Nuclides Will the Next
Generation Facilities Produce?
• FRIB will produce more
than 1000 NEW
isotopes at useful rates
(4500 available for
study; compared to
1700 now)
• Theory is key to making
the right measurements
• Exciting prospects for
study of nuclei along the
drip line to mass 120
(compared to 24)
• Production of most of
the key nuclei for
astrophysical modeling
• Harvesting of unusual
isotopes for a wide
Rates are available at http://groups.nscl.msu.edu/frib/rates/
range of applications
Brad Sherrill WG.9 July 2010, Slide 14
Slid 14
Rare Isotope Production
Techniques using Accelerators
• Target spallation and fragmentation by light ions (Used by TRIUMF, HRIBF)
Target/Ion Source
Post
Accelerator
Acceleration
• Neutron or photon induced fission (TRIUMF)
Neutrons/Photons
Post
Accelerator
Acceleration
beam
target
• In-flight Separation following projectile fragmentation/fission (Used by FRIB)
beam
Accelerator
Beams used without stopping
Post
Acceleration
Beam
Fragment Separator
target
Gas catcher/ solid catcher + ion source
Brad Sherrill WG.9 July 2010, Slide 15
Slid 15
Rare Isotope Facilities in North
America
• Notre Dame University – in-flight light ions
• Florida State RESOLUTE – in-flight light and mid-mass ions
• Texas A&M Upgrade – ISOL, Gas Catcher, in-flight, accelerated to 50
MeV/u
• ANL CARIBU – Cf fission source, in-flight light and mid-mass ions
• ORNL HRIBF – ISOL production by 40 MeV light ions; fission
fragments
• NSCL – 100 MeV/u in-flight ions
• TRIUMF ISAC I and II, ARIEL – megawatt class photo fission source,
ISOL beams to 8 MeV/u
• FRIB – 400 kW, 200 MeV/u in-flight separation, gas stopping,
reacceleration to 20 MeV/u
Brad Sherrill WG.9 July 2010, Slide 16
Slid 16
RESOLUT: a new
radioactive beam facility at FSU
Solenoid
2
Magnetic
Spectrograph
Solenoid 1
Target Position
RF-Resonator
Magnetic Spectrograph
Mass selection
slits
RF-Resonator
Production
target
Experiment

In-flight production of radioactive beams in inverse kinematics

Combination of Superconducting RF-Resonator with high acceptance
magnetic Spectrograph to create mass spectrometer
Brad Sherrill WG.9 July 2010, Slide 17
Slid 17
Study of light exotic nuclei through resonance reactions at RESOLUT
(G. Rogachev et al.)
Excitation function of elastic
(top) to inelastic p+7Be
scattering (bottom), showing the
presence of additional
resonances in 8B, observed
through
inelastic scattering only
Excitation functions of elastic
(top) to inelastic p+7Be
scattering (bottom) at various
angles, R-matrix fit fit with
additional resonances included.
Brad Sherrill WG.9 July 2010, Slide 18
T-REX
[TAMU Reaccelerated Exotics]
Brad Sherrill WG.9 July 2010, Slide 19
Slid 19
Science accessible with the TAMU upgrade
• Nuclear Astrophysics – indirect techniques
• Nuclear Structure – transfer reactions, g spectroscopy, …
• Fundamental Interactions – trapping expts.
• Dynamics and Thermodynamics – N/Z degrees of freedom
Brad Sherrill WG.9 July 2010, Slide 20
Slid 20
Projected Beam Intensities from LIG after K500
(p,n)
Max. Energy
Intensity
Product
MeV/A
particles/s
27Si
57
6 x 103
50Mn
45
2 x 104
54Co
45
6 x 103
64Ga
45
4 x 104
92Tc
35
4 x 104
106In
28
4 x 104
108In
28
3 x 104
110In
26
6 x 104
Assuming 14 mA beam, realistic LIG, CBECR,
transport and K500 extraction efficiencies
Examples of reaccelerated beams produced in DIC:
Isotope
t1/2>100ms
Calculation details in
poster by G. Souliotis
Max. Energy
MeV/u
Neutron rich
9
Li
11
Be
22
O
24
Ne
32
Mg
38
S
40
S
42
S
42
Ar
44
Ar
46
Ar
62
Fe
60
Cr
45
45
40
40
40
36
32
29
39
38
35
38
32
Proton rich
7
Be
8
B
11
C
14
O
22
Mg
23
Al
27
P
62
Ga
64
Ga
60
70
63
70
57
60
62
47
45
2.0-4.
Intensity
Pps
1.7-3.4106
0.7-1.4106
2.0-4.0104
0.5-1.0104
1.3-2.6104
2.5-5.0105
0.5-1.0105
1.8-3.6103
3.3-6.6105
0.9-1.8105
1.8-3.6104
1.9-3.8104
0.5-1.0103
0.5-1.0106
1.2-2.4106
1.3-2.6106
0.7-1.4105
3.1-6.3104
1.2-2.4103
1.0-2.0103
2.1-4.3102
0.9-1.9104
Brad Sherrill WG.9 July 2010, Slide 22
ATLAS Tomorrow: CARIBU & Energy Upgrade & HELIOS:
Unique Synergy
 CARIBU gives access to exotic beams not available elsewhere.
 Physics with beams from CARIBU (1 & 2 nucleon transfer reactions) needs the new energy regime
opened by the Energy Upgrade (12 MeV/u) .
 Solenoid Spectrometer greatly expands the effectiveness of both the fission fragment beams and the
existing in-flight RIB program at these higher energies.
 These three projects combine to form a truly unique facility which complements the capabilities of
other world facilities in the era leading to FRIB
CARIBU
CARIBU upgrade
ATLAS Energy
Upgrade
HELIOS
Brad Sherrill WG.9 July 2010, Slide 23
Slid 23
CARIBU
CARIBU upgrade
• CARIBU Plan:
Spring 2010: 2 mCi source  tests & yields studies
Summer-Fall 2010: 100 mCi source  1st test expts.
End 2010: 1 Ci source  Full research program
Brad Sherrill WG.9 July 2010, Slide 24
Slid 24
CARIBU: Main Science Focus
- Astrophysics: towards the r-process path
Path critically depends on nuclear properties of neutron-rich nuclei:

 mass, lifetime, b-delayed neutrons, fissionability
All marked nuclei accessible with 80 mCi
continuation of CPT program, Greatly benefits from even the weakest source
source
and requires > 0.1 ion/s
New CPT/
Old CPT
Measurements
-Nuclear
Structure:
Changes
in shell
All but about
half of the
grey nuclei
are structure and new collective modes:
accessible
with
2.5 mCi with
source
 Shell
structure
single-nucleon transfer
 Pair correlations with transfer of nucleon pairs
 CPT
to CARIBU
 moved
Collective
modes with Coulomb Excitation
decay
studies
CARIBUand
enables
the
initial exploration of the heavy
 Decay studies with X-array & tape system
region using precision low-energy
-neutron-rich
Reaction dynamics
transfer reactions and helps develop and test the
 Fusion with n-rich nuclei
required techniques
 Deep
inelastic reactions
 HELIOS & other techniques (GS&FMA,..)
 Surrogate reactions
Coulomb excitation & decay studies will address
issues such as octupole collectivity in the Kr and Ba
regions, triaxiality in the neutron-rich Mo and Pd
regions, shape coexistence and new symmetries in Sr
and Ce regions
 Gammasphere & FMA, GRETINA, CHICO,..
Brad Sherrill WG.9 July 2010, Slide 25
Slid 25
HRIBF
25MV Tandem
Electrostatic
Accelerator
Injector for Radioactive
Ion Species 1 (IRIS1)
Injector for
Stable Ion
Species (ISIS)
Oak Ridge Isochronous
Cyclotron (ORIC)
Enge
Spectrograph
Daresbury Recoil
Separator (DRS)
High Power Target
Laboratory (HPTL)
On-Line Test
Facility (OLTF)
26
Managed by UT-Battelle
for the U.S. Department of Energy
Recoil Mass
Spectrometer
(RMS)
HRIBF Post-accelerated Beams
175 RIB species available
(+26 more unaccelerated)
32 proton-rich species
143 neutron-rich species
Post-accelerated Intensity
Beam list increased by ~50% since 2003
27
Managed by UT-Battelle
for the U.S. Department of Energy
Science highlights in 2009/2010
HRIBF General public highlights:
http://www.phy.ornl.gov/hribf/science/abc/2009/
Experiments and outcomes
http://www.phy.ornl.gov/hribf/experiments/results/
The magic nature of 132Sn explored
through the single-particle states of 133Sn
K. L. Jones et al., Nature, May 27 (2010)
(discussed by Jones)
Brad Sherrill WG.9 July 2010, Slide 28
Slid 28
Brad Sherrill WG.9 July 2010, Slide 29
Brad Sherrill WG.9 July 2010, Slide 30
10 μA of 500 MeV protons on 238U (22 g/cm2)
Fundamental Symmetries
Radon EDM, Fr PNC
208Pb
Evolution of shell
structure:
towards the r
process path
132Sn
78Ni
Halo nuclei and
neutron skin
Brad Sherrill WG.9 July 2010, Slide 31
Initial tests completed in Aug 2008, expect license for routine operation by fall
Present status of the Ariel Project
• 50 MeV, 500 kW superconducting e-linac funded
• requires matching funding from BC province for
buildings (funded)
• second proton beamline deferred until next 5YP
Brad Sherrill WG.9 July 2010, Slide 32
Photo-fission of 238U (7 g/cm2)
10 mA, 50 MeV electrons on Hg
converter
High yields and fewer
isobaric
contaminants
132Sn
Evolution of shell
structure: towards
the r process path
78Ni
Brad Sherrill WG.9 July 2010, Slide 33
Rare Isotope Beam Production – Coupled
Cyclotron Facility, CCF
CCF
Parameters
ECR ion sources
• 90 to 200 MeV/u
• 1 pnA 238U
• 80 pnA 48Ca
K500
K1200
A1900
A1900 Parameters
A1900
Morrissey et al., NIM B 204, 90 (2003)
•
•
•
•
Dp/p ~5% max
Br = 6.0 Tm max
8 msr solid angle
35 m in length
NuSTAR B.M Sherrill, 3/5/2010, Slide 34
Exotic Beams Produced at NSCL
More than 1000 RIBs have been made – more
than 830 RIBs have been used in experiments
12 Hours for a primary beam change; 3 to 12 hours for a secondary beam
NuSTAR B.M Sherrill, 3/5/2010, Slide 35
Facility for Rare Isotope Beams,
FRIB Broad Overview
• Driver linac capable of E/A  200 MeV for all ions,
Pbeam  400 kW
• Early date for completion is in 2018
• In-flight 200 MeV/u, stopped, reaccelerated to 20 MeV/u
LBNL
Brad Sherrill WG.9 July 2010, Slide 36
Slid 36
Compact, more cost-effective solution
Project Manager:
Thomas Glasmacher
Director: Konrad Gelbke
TPC estimate $614M
CD-4 Range 2018-2020
Brad Sherrill WG.9 July 2010, Slide 37
Slid 37
Summary
• We have entered the age of designer atoms – new tool for science
• High power in-flight facility at FRIB and ISOL facilities at TRIUMF
will allow production of a wide range of new isotopes
– Necessary for the next steps in accurate modeling of atomic nuclei
– Necessary for progress in astronomy (chemical history, mechanisms of
stellar explosions)
– Opportunities for the tests of fundamental symmetries
– Important component of a future U.S. isotopes program
• Other facilities play a key role in cost effective development of
programs and techniques, e.g., ANC method developed at Texas
A&M and resonance methods being developed at FSU
• New applications range from nuclear modeling, astrophysics,
fundamental interactions, and use of isotope
Brad Sherrill WG.9 July 2010, Slide 38
Slid 38
FRIB specialty – Produce new exotic
isotopes
V(r)
• Large neutron skins
• Modified mean field
• Resonance properties
11Li
r
208Pb
New
80Ni
Science: Pairing in low-density material, new tests of nuclear models, open
quantum system, interaction with continuum states - Efimov States - Reactions
Brad Sherrill WG.9 July 2010, Slide 39
Slid 39
How do we model nuclei?
• The origin of the strong force that binds nuclei is QCD. How would we
prove that? Surprises are likely.
• We construct potentials based on neutron and proton scattering data
and properties of light nuclei (Bonn, Reid, Illinois AV18, Nijmegen, etc.)
• QCD Inspired EFT (String Theory Inspired – Hashimoto et al.)
S Aoki
Goal:
Develop an
Effective
Field Theory
based on
QCD
Symmetries
(Furnstahl,
van Kolck,
Navrátil, Vary,
Machliedt…)
Brad Sherrill WG.9 July 2010, Slide 40
Slid 40
Properties of exotic isotopes are essential
in determining NN and NNN potentials
• Neutron rich nuclei were key
in determining the isospin
dependence of 3-body forces
and the development of IL-2R
from UIX
S. Pieper
B.Wiringa,
et al.
• New data on exotic nuclei
continues to lead to
refinements in the
interactions
• EFT developments, LQCD
and even computational
power are providing insight
for ab initio theories, but they
need grounding in data
Brad Sherrill WG.9 July 2010, Slide 41
Slid 41
Current status of the GFMC
calculations
FRIB Theory workshop talks of
J. Carlson, K. Nollet
Brad Sherrill WG.9 July 2010, Slide 42
Slid 42
Configuration space models –
Example Coupled Cluster
Thomas Papenbrock et al. Univ of Tennessee, FRIB
Theory Workshop
Brad Sherrill WG.9 July 2010, Slide 43
Slid 43
Solar System Elemental Abundances
• Understanding the chemical history of the universe
• The abundance of elements tell us about the history of events prior to
stellar formation
Solar system abundances
Lodders (2003)
Brad Sherrill WG.9 July 2010, Slide 44
Slid 44
Simulation of Solar System Abundances
Parameters:
• Supernovae type Ia and
II
• Number (77 supernovae
with Ms 11-40 Msun)
• Progenitor mass
distributions
• Age of the galaxy
• …
Results:
• SN rate1/3 comes from
type Ia
• Reproduction of
measured 7Li abundance
metalicity vs. time etc.
Timmes, Woosley, Weaver
Astrophysical Journal 1995
Success ! ? Above 72 we can’t model well
Brad Sherrill WG.9 July 2010, Slide 45
Slid 45
Goal: Understanding of
Astrophysical Environments
• Use observational data to infer
conditions at the site by modeling
• Accurate modeling requires
• that we make the same isotopes
that participate in astrophysical
environments
• reproduce the nuclear reactions
that occur in those environments
• The hard part is that nature
produces isotopes in environments
like the r-process with T > 109 K,
rneutron ≈ 1020-28 cm-3
Sneden 2003; Cowan 2006
model
n-star mergers
observation
Crab
Nebula
Price & Rosswog 2006
Mt Palomar
Brad Sherrill WG.9 July 2010, Slide 46
Slid 46
Where do gold atoms come from?
An r-process
• E. M. Burbidge, G. R. Burbidge, W. A. Fowler, and F. Hoyle. (1957).
"Synthesis of the Elements in Stars". Rev Mod Phy 29: 547, must be an rprocees, but …
• We know they must be made in a neutron-rich environment T > 109 K,
rneutron ≈ 1020-28 cm-3 , that lasts for about 1 second; called the rapid-neutron
capture process, r-process
• Type II supernovae are a possible site (variants)
– Neutrino driven shock wave
– Models do not produce the entropy and neutron flux needed to match abundance data
(although we can’t say that for sure)
– Shock waves in C-O layers
– Magnetic outflows
• Colliding neutron stars would also work, but there does not seem to be
enough of these in the early universe to explain how much heavier
elements we see
• Once the underlying physics is known, we can infer information of the site
Brad Sherrill WG.9 July 2010, Slide 47
Slid 47
About Half of Heavier Elements
must be made in an r-Process
(Click on image to start animation)
Nuclear physics shapes the characteristic final abundance pattern
for a given r-process model
Brad Sherrill WG.9 July 2010, Slide 48
Slid 48
Uncertainty between models
and nuclear properties
Astrophysics
101
Hot bubble
Classical model
Same nuclear physics
100
Abundance
Nuclear physics
1
10
0
10
Same (classical) r-process model
-1
10-1
10
10-2
10
10-3
10
10-4
ETFSI-Q masses
ETFSI-1 masses
-2
-3
Freiburghaus et al. 1999
-4
10
Mass number
100
120
140
160
180
200
220
Mass number
Brad Sherrill WG.9 July 2010, Slide 49
Slid 49
Mass Uncertainties and r-process
• Are the fine details a reflection of the site or of nuclear physics?
B. Sun et al. PRC 78 025806 (2008)
• “Site independent model” – Fe seed nuclei are irradiated with ≈ 20
flashes of 1020 to 1028 n/cm3 over a time scale of seconds (T ≈ 1 GK)
Brad Sherrill WG.9 July 2010, Slide 50
Slid 50
Reach of FRIB – Will Allow
Modeling of the r-Process
• β-decay properties
• masses (Trap + TOF)
• (d,p) to constrain (n,γ)
• fission barriers, yields
82
Known half-life
FRIB reach
for (d,p)
N=126
126
50
Current
NSCL reach
reach
First experiments
(70) Yb
(69) Tm
82
28
(68) Er
(67) Ho
(66) Dy
50
FRIB reach for
half-lives
RISAC
Key
Nuclei
Future
Reach
Brad Sherrill WG.9 July 2010, Slide 51
Slid 51
Type I-X ray bursts
http://plus.maths.org/issue23/news/xray/index.html
Brad Sherrill WG.9 July 2010, Slide 52
Slid 52
Rare Isotope Crusts of Accreting
Neutron Stars
KS 1731-260
(Chandra)
Cackett et al. 2006 (Chandra, XMM-Newton)
 Nuclear reactions in the crust set
thermal properties
 Can be directly observed in transients
 Directly affects superburst ignition
Understanding of crust reactions offers possibility to constrain neutron star
properties (core composition, neutrino emission…)
Brad Sherrill WG.9 July 2010, Slide 53
Slid 53
2
1
 Fix one key parameter
(more meaningful model comparisons)
 Determine Eddington Luminosity
XH=0.29
XH=0.55
(apparent Ledd from PRE bursts)
 Standard candle/distance
 Constrain EOS
 model atmosphere in transients
H. Schatz, Brown 2002, Schatz 2001
XH=0.66
Mass uncertainties in 64Ge – 74Sr region:
Mass uncertainties
within AME95
(Brown et al. 2002)
Luminosity (erg/g/s)
erg/g/s/1e17
H-fraction in surface from X-ray
burst light curves
New trap mass measurements
Schury et al. 2007 (LEBIT)
Rodriguez et al. 2004 (ISOLTRAP)
Clark et al. 2004, 2007 (CPT)
Time (s)
Brad Sherrill WG.9 July 2010, Slide 54
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Rare Isotopes For Society
• Isotopes for medical research
– Examples: 47Sc, 62Zn, 64Cu, 67Cu, 68Ge, 149Tb, 153Gd, 168Ho, 177Lu, 188Re, 211At, 212Bi,
213Bi, 223Ra (DOE Isotope Workshop)
– -emitters 149Tb, 211At: potential treatment of metastatic cancer
– Cancer therapy of hypoxic tumors based on 67Cu possible is a source would be
available
• Reaction rates important for stockpile stewardship and nuclear power –
related to astrophysics network calculations
– Determination of extremely high neutron fluxes by activation analysis
– Rare isotope samples for (n,g), (n,n’), (n,2n), (n,f) e.g. 88,89Zr
» Same technique important for astrophysics
– More difficult cases studied via surrogate reactions (d,p), (3He, xn) …
• Tracers for Geology (32Si), Condensed Matter (8Li), material studies, …
• Special isotopes for homeland security applications (β-delayed neutron
emitters to calibrate detectors, etc.)
Brad Sherrill WG.9 July 2010, Slide 55
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Separated Isotopes from FRIB
Half-life limit set at 1 minute
Brad Sherrill WG.9 July 2010, Slide 56
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DOE Workshop Report Appendix H
Isotopes with Future Demand > Supply
Isotope
FRIB mCi (4 hour)
Comment
Actinium-225
0.063
Significant gain from ISOL capability
Promethium-147
1x1014 atoms
Astatine-211
3.5
Nickel-63
1x1016 atoms
Chlorine-36
1x1016 atoms
Cesium-137
1x1013
1000 gain if ISOL used
Gallium-68
1310
Additional alternative Ga isotopes
Iridium-192
1x1014 atoms
Copper-67
750
Silicon-32
1x1016 atoms
100 gain from ISOL capability
Additional alternative Cu isotopes
http://www.er.doe.gov/np/program/isotope.html
Brad Sherrill WG.9 July 2010, Slide 57
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Sensitivity of Nuclear
Properties to Model Parameters
• Example: Level structure of 24O and the 1S0 NN interaction
• Structure of these loosely bound or unbound isotopes is strongly
influenced by the 1S0 component of the NN interaction
• Calculation of 24O in a shell model that correctly treats weakly-bound
and continuum states (specifically Gamow Shell Model)
Tsukiyama, Horth-Jensen, Hagen PRC 80 051301(2009)
Brad Sherrill WG.9 July 2010, Slide 58
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How do we know QCD is responsible for
nuclei?
• Lattice QCD has the promise to
verify QCD as the correct
description for the strong force
in nuclei
• The lattice may be able to
provide the isospin dependence
of the NNN force needed to
understand nuclei
• Comparison of this dependence
to rare isotope data allows a
test of lattice QCD in nuclei
Theory
Experiment
T. Otsuka
Accepted PRL
NNN force may be the solution
to understanding the Oxygen
drip line
Brad Sherrill WG.9 July 2010, Slide 59
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FRIB Users
www.fribusers.org
• FRIB Equipment Workshop held Feb. 20-22, 2010 in East Lansing
– 265 registered participants from
76 institutions in 15 countries
– 18 working groups held sessions
and presented summaries
– SAC report released (see website)
– meetings.nscl.msu.edu/
frib-equipment-workshop2010/
program.htm
 Prior workshop held May 30-31, 2009 at Argonne National Laboratory
• “Step Forward to FRIB"
• 210 registered participants from
47 institutions in 11 countries
• www.fribusers.org/
4_GATHERINGS/4_ARCHIVE/
05_09/05_09.html
Brad Sherrill WG.9 July 2010, Slide 60
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Density Functional Theory
M. Stoitsov et al.
• EDF calculation of the
binding energies of
9000 isotopes (M.
Stoitsov et al.)
• Key tests of the theory
come at the limits of
binding (see figure)
• Remarkable success
so far; Global DFT
mass calculations
from HFB Δm~700keV
• Goal is to achieve the
kind of results
obtained in quantum
chemistry
Brad Sherrill WG.9 July 2010, Slide 61
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World view of rare isotope facilities
Black – production in target
Magenta – in-flight production
Brad Sherrill WG.9 July 2010, Slide 62
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