Brad Sherrill
Facility for Rare Isotope Beams
26 June 2013
FRIB Physics Program
Development of a comprehensive model of atomic nuclei – How do we understand the structure and stability of atomic nuclei?
Understanding the origin of elements and modeling of extreme astrophysics environments
Use of atomic nuclei to test fundamental symmetries (e.g. in a search for CP violation)
Applied isotope science – new applications of isotopes
Outline
RHIC Users Meeting June 2013, Slide 2
One of the Challenges – How many elements?
- P. Pyykkö: Phys. Chem. Chem. Phys. 13, 161-168 (2011) “Half of chemistry is undiscovered.”- Another view – above Z=122 all chemistry is the same due to relativistic effects- For stability of Z>120 see also Jachimowicz, Kowal, Skalski, PRC 83 (2011)
RHIC Users Meeting June 2013, Slide 3
Claims for up to Z=118, but much beyond requires theory – application of Density Functional Theory
Stars are mostly made of hydrogen and helium, but each has a fairly unique pattern of other elements
The abundance of elements tell us about the history of events prior to the formation of our sun
The plot at the right shows the composition in the visible surface layer of the Sun (photosphere)
How were these elements created prior to the formation of the Sun?
One of the Challenges – Origin Elemental Abundances in our Solar System
Hydrogen
XLogdex 12
Asplund, M., Grevesse, N., Sauval, A.J., Scott, P.: Annu. Rev. Astron.Astrophys. 47, 481 (2009)
RHIC Users Meeting June 2013, Slide 4
Challenge: Nuclei from NN Interactions
- How do we model atomic nuclei? QCD, but we need approximations
- Modern approaches to NN potentials include - QCD Inspired EFT - Epelbaum, Machleidt, …- String Theory Inspired – Hashimoto …- Lattice QCD – Detmold, Aoki …
RHIC Users Meeting June 2013
N. Ishii, S. Aoki, T. Hatsuda, Phys. Rev. Lett. 99, 022001 (2007)
, Slide 5
Theory “Data”
Two-nucleon, three-nucleon, etc. interactions are a foundation. What if they are imbedded in a nucleus?
Are protons and neutrons in medium modified from their free structure? Maybe: EMC Effect and recent results from JLAB indicate yes
What affect does nucleon structure have on nuclear structure?What other effects are present but unrecognized?
Goal: Comprehensive Understanding of Nuclei
RHIC Users Meeting June 2013, Slide 6
12C Nucleus
The Road Map: A Comprehensive Model of Atomic Nuclei
Step 1: Start from NN forces (ab initio theory) and study of light rare isotopes to determine the interactions of nucleons in nuclei and connect these to QCD by comparison to lattice calculations of NN, NNN forces, and couplings in EFT
Step 2: For mid-mass nuclei use configuration interaction models. The degrees of freedom and interactions must be determined from rare isotopes
Step 3: Use density functional theory, DFT, to connect to heavy nuclei. Rare isotopes help determine the form and parameters of the DFT.
RHIC Users Meeting June 2013, Slide 7
Rare isotopes play a key role at each step.
Pictoral version of the Theory Road Map – Goal is a “standard model” for understanding nuclei
Colors indicate the yields from FRIB. Access to a wide range and nuclei along the drip lines is critical
Theory Road Map: Comprehensive Model of Nuclear Structure and Reactions
Ab initio
Configurationinteraction
Energy density functional
Continuum
Relationship to QCD (LQCD)
RHIC Users Meeting June 2013, Slide 8
Comparison of Calculated and Measured Binding Energies with NN models
Greens Function Monte Carlo techniques allow up to mass number 12 to be calculated
Blue 2-body forces V18
S. Pieper B.Wiringa, et al.
NN potentialNN + NNN potential
RHIC Users Meeting June 2013, Slide 9
New information from exotic isotopes
• Neutron rich nuclei were key in determining the isospin dependence of 3-body forces and the development of IL-2R from UIX
• New data on exotic nuclei continues to lead to refinements in the interactions
NN + improved NNN potential
Properties of exotic isotopes are essential in determining NN and NNN potentials
S. Pieper B.Wiringa, et al.
RHIC Users Meeting June 2013, Slide 10
Current status of the GFMC calculations
Carlson, Pieper, Wiringa, et al.
RHIC Users Meeting June 2013, Slide 11
Resonance states in 5He (n+4He)
Application of GFMC technique to reactions of nuclei important to BB Nucleosynthesis
K. Nollett, et al, PRL 2007; motivated by BBN modeling
RHIC Users Meeting June 2013, Slide 12
Importance of 3N forces
Big Bang Nucleosynthesis: Calculate all key reactionsNeutron star masses
Half-life of 14C (Maris, Navratil et al. PRL), structure of calcium isotopes (Wienholtz et al. Nature), etc.
RHIC Users Meeting June 2013
Gandolfi et al., PRC85, 032801 (2012)
Nazarewicz et al.
, Slide 13
Construct NN Potentials: EFT based on QCD Symmetries – “Chiral”
Use the features of the pion in constructing an effective theory
Effective Field Theory, EFT, based on QCD Symmetries (Weinberg,Epelbaum ,Furnstahl, Machleidt, van Kolck, Navrátil,… )
Cut-off parameter Λ ≅ 500 MeV
Contact interactions have constants that are fit to experiment
Picture from E. Epelbaum
RHIC Users Meeting June 2013, Slide 14
Standard Shell Model
RHIC Users Meeting June 2013, Slide 15
Mayer and Jensen Nobel prize in 1963 “"for their discoveries concerning nuclear shell structure"
picture Niels WaletN l2 potential Spin-Orbit
Magic Numbers
Stability of Magic Nuclei
RHIC Users Meeting June 2013
Harder to excite
, Slide 16
Stability of Magic Nuclei
RHIC Users Meeting June 2013
Harder to excite
20 protons
16 protons
14 protons
, Slide 17
Surprise: Changing Magic Numbers
RHIC Users Meeting June 2013
Harder to excite
Reason: A tensor force that depends on angular momentum and isospin (Otsuka et al.)
, Slide 18
Widely used in Chemistry– based on Hohenberg-Kohn (Phy Rev 136)
Relies on the variation concept where observables are treated as variational parameters, e.g. local density ρ(r) and its derivative
We don’t know the correct form for nuclei. Example: Skyrme functional
Use rare isotopes to test functional forms, determine parameters, provide insight for improvements
Step 3: Density Functional Theory
RHIC Users Meeting June 2013, Slide 19
N. Schunck, Exotic Beam Summer School 2012
Prediction of the limits of the nuclear landscape
RHIC Users Meeting June 2013
J. Erler et al., Nature 486, 509 (2012)
265 stable isotopes, 3100 observed, more like 2000 “known”, 6900(600) possible
, Slide 20
Weakly bound isotopes have unique features
220Rn
“Halo”Tanihata PRL1985
“Skin”Tanihata PLB1992
11Li80Ni
New
Science: Pairing in low-density material, new tests of nuclear models, open quantum system, interaction with continuum states - Efimov States - Reactionssee e.g. H.-W. Hammer and L. Platter, Ann. Rev. Nucl. Part. Sci. 60, 207 (2010)
RHIC Users Meeting June 2013, Slide 21
“Normal”
Weakly Bound Nuclei are Open Quantum Systems
RHIC Users Meeting June 2013, Slide 22
Dobaczewski et al., Prog. Part. Nucl. Phys. 59, 432 (2007)
W Nazarewicz
RHIC Users Meeting June 2013
One of 11 Science Questions for the 21st century
How were the elements from iron to uranium made?• Where and how does the r-process occur?
The Origin of the Elements
, Slide 23
New data on elemental abundances: Surveys and Large Aperture Telescopes
The measurement of elemental abundances is at the forefront of astronomy using large telescopes
Large mirrors enable high resolution spectroscopic studies in a short time (Subaru, Hubble, LBT, Keck, …)
Surveys provide large data sets (SDSS-III, RAVE, LAMOST, SkyMapper, LSST…)
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.”
HubbleSpace
RHIC Users Meeting June 2013, Slide 24
SUBARU
Simulation of Solar System Abundances
Timmes, Woosley, Weaver Astro. Journal 1995
Success ! ? Note above A=72 we can’t model
RHIC Users Meeting June 2013, Slide 25
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 • They reproduce
measured 7Li abundance metalicity vs. time etc.
Neutron-capture process leading to elements heavier than iron
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 r-process (10% of gold from s-process)
Rapid neutron capture process, r-process• Fast, few second duration• Neutron density of 1020-28 n/cm3
• Runs out to where (n,γ) and (γ,n) are similar in rate• Adds 30-40 neutrons• Site unknown
AZ
fission
(n,γ)
Reaction path(γ ,n)
(n,γ)
β-
RHIC Users Meeting June 2013, Slide 26
…
RHIC Users Meeting June 2013
We now have several robust, self-consistent r-process models; to test them against observations, we need nuclear data
Advances in Theoretical Astrophysics
NeutronStar Mergers
MHD Supernova Jets
Neutrino Driven Wind
Hoffman et al. 2008
Winteler et al. 2012
Korobkin et al. 2012
40 60 80 100Mass number
1
10
abun
danc
e
Mass number
, Slide 27
Hoffman et al. 2008
100 120 140 160 180 200 22010-4
10-3
10-2
10-1
100
101
Nuclear physicsHot bubbleClassical model
Same nuclear physics
ETFSI-Q massesETFSI-1 masses
Mass number Mass number
Freiburghaus et al. 1999
Astrophysics
10-4
10-3
10-2
10-1
100
101
Same (classical) r-process model
Uncertainty between models and nuclear properties
Abu
ndan
ce
RHIC Users Meeting June 2013, Slide 28
H. Schatz
RHIC Users Meeting June 2013
N=82
N=126
Critical region probes:Main r-process parametersProduction of actinides
Critical region probes:r-process freezeout behavior(Mumpower et al. 2012)
Critical region probes:Main r-process parametersCritical region probes:
Neutrino fluence
Different key-regions probedifferent model aspectswhen compared to observations
Critical region: Disentangler-processes
New Facilities will Enable the Needed Breakthrough in Nuclear Physics
H Schatz
, Slide 29
RHIC Users Meeting June 2013
FRIB reach for T1/2, masses,and β-delayed neutron emission(Overlap with applications!)
N=82
N=126
Critical region probes:Main r-process parametersProduction of actinides
Critical region probes:r-process freezeout behavior(Mumpower et al. 2012)
Critical region probes:Main r-process parametersCritical region probes:
Neutrino fluence
Different key-regions probedifferent model aspectswhen compared to observations
Critical region: Disentangler-processes
New Facilities will Enable the Needed Breakthrough in Nuclear Physics
H Schatz
, Slide 30
RHIC Users Meeting June 2013
Stellar Hydrogen Explosions:Common (100/day) and Not Understood
Open questions• Neutron star size• Short burst intervals• Multiple peaked bursts• Nature of superbursts• Ejected mass (Nucleosynthesis)
• Observable gamma emitters
• Why such a variety • Path to Ia supernovae
, Slide 31
www4.nau.edu
RHIC Users Meeting June 2013
Need nuclear data on rare isotopes to create reliable model templates to analyze observations
Making Sense of X-ray BurstObservations
~5000 widely varying bursts
Burst profiles depend on nuclear rates
With accurate model templates• Absolute peak flux, distance• H/He composition• Redshift + color correction
(distance and anisotropy independent) neutron star size
Amthor, Cyburt et al. 2012
Zamfir et al. 2012
GS 1826-24
Redshiftvariation
Galloway et al.
, Slide 32
108-9
107-8
106-7
105-6
104-5
102-4
109-1010>10
All reaction rates up to ~Ti can be directly measured
most reaction rates up to ~Sr can bedirectly measured
key reaction rates can be indirectly measured including 72Kr waiting point
direct (p,g)
direct (p,a) or (a,p)transfer
(p,p), some transfer
rp-process
FRIB Reach for Novae and X-ray burst reaction rate studies
RHIC Users Meeting June 2013, Slide 33
Rare Isotope Crusts of Accreting Neutron Stars
Nuclear reactions in the crust set thermal properties (e.g. cooling)
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…)
Cackett et al. 2006 (Chandra, XMM-Newton)
KS 1731-260(Chandra)
H. Schatz
RHIC Users Meeting June 2013, Slide 34
RHIC Users Meeting June 2013
Where do Neutrons Drip?
Dripline known
K.-Y. Lau, M. Beard, P. Shternin, et al., to be published
FRIB reach:dripline up to A~100+ mass measurements+ EC rates via charge exchange
Known mass
, Slide 35
RHIC Users Meeting June 2013
• Angular correlations in β-decay and search for scalar currentso Mass scale for new particle
comparable with LHCo 6He and 18Ne at 1012/s
• Electric Dipole Momentso 225Ra, 223Rn, 229Pa (10,000x more
sensitive than 199Hg; 229Pa > 1010/s)• Anapole moment in Fr atoms
o Understanding of weak interactions in nuclei (francium isotopes; 1010/s)
• Unitarity of CKM matrixo Vud by super allowed Fermi decay o Probe the validity of nuclear
corrections
Are the fundamental interactions that are basic to the structure of matter fully understood?
e
γ
Z
212Fr
Adopted from Savard et al.
, Slide 36
FRIB offers fast development of 1000s of isotopes (via harvesting) 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 treatment/64Cu dosimetery
Reaction rates important for stockpile stewardship and nuclear forensics• 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• More difficult cases studied via surrogate reactions (d,p), (3He,a xn) …• We can produce quantities of separated fission products for tests of
detection techniquesTracers for Marine Studies (32Si), Condensed Matter (8Li), industrial
tracers (7Be, 210Pb, 137Cs, etc.), …Data for advance reactor design and destruction of nuclear waste
Rare Isotopes For Society
RHIC Users Meeting June 2013, Slide 37
We are entering a new era in nuclei physics when we can produce and study key rare isotopes:
Development of a standard model for nuclei• What are the heaviest elements possible?• What is the origin of the nuclear force in QCD and EW• In 15 years we might know the answer
Foundation for astrophysical modeling• With new rare isotopes we will be able to better model stellar processes• We will have the ability to understand the history of a star (or meteorite)• Modeling of neutron stars, novae, supernovae will be on a more solid footing
Search for symmetry violations, e.g. atomic EDMs • enhanced sensitivity from FRIB will allow most of the interesting EDM scales
to be covered
Summary
RHIC Users Meeting June 2013, Slide 38
Funded by DOE Office of Science – 2020 completion
Key Feature is 400kW beam power (5 x1013 238U/s)
Separation of isotopes in-flight• Fast development
time for any isotope• Suited for all
elements and short half-lives
Major US Project – Facility for Rare Isotope Beams, FRIB
RHIC Users Meeting June 2013, Slide 39
New Insight from Mass Model Comparison to Data
J. Duflo, A.P. Zuker, Phys. Rev. C52 (1995) R23Shell Model Based MEDZ – MEAME2003
HFB-14: Hartree-Fock-Bogoliubov w/delta pairing forceS. Goriely, M. Samyn, J.M. Pearson, Phys. Rev. C75 (2007) 064312
MEHFB14 – MEAME2003
ME = (Actual mass – A u) x 931.5 MeV/uu = atomic mass unit (931.5 MeV)
More bound than data
Less bound than data
www.nuclear masses.org
RHIC Users Meeting June 2013, Slide 40
“Ab Initio” start with NN forces
Approach: Construct NN potentials based on neutron and proton scattering data and properties of light nuclei (Bonn, Reid, Illinois AV18, Nijmegen, etc.)
More recent approach is to construct the potentials some more fundamental theory• QCD Inspired EFT • String Theory Inspired – Hashimoto
et al• Lattice QCD
N. Ishii, S. Aoki, and T. Hatsuda, Phys. Rev. Lett. 99, 022001 (2007)
RHIC Users Meeting June 2013, Slide 41
The interaction of nuclei create a “mean field”. We think of nucleon moving in this potential.
Shell Model is the most common in nuclear scienceSolve the equation HΨ=EΨ
Introduce a basis (usually harmonic oscillator) and solve the matrix equation
Can assume inert closed cores for certain nuclei (e.g. N=Z=20)No core shell model does not make this assumption All shell models use effective operators (interactions depend on model
space
Configuration Interaction Models
RHIC Users Meeting June 2013, Slide 42
12C
Use ab initio interactions derived by some means like EFT or fits to NN scattering in a shell model
Diagonalize in a large basis of many-body states
“No Core” Shell Model
RHIC Users Meeting June 2013, Slide 43
From A. Poves, International School on Exotic Beams, Santiago de Compostela, September 4-11 2010 (see also J Vary, etc.)
FRIB Reach For Crust Processes• Interesting set of reactions leading to proton-rich material converted to
neutron-rich material
Electron capture rates
Haensel & Zdunik Astro Journ 1990, 2003, 2008Gupta et al. Astro Journ 2006
Known mass
Mass measurements
Drip line established
H. Schatz
RHIC Users Meeting June 2013, Slide 44
There are a number of nucleosynthesis processes that must be modeled
Big Bang Nucleosynthesis pp-chainCNO cycle triple alphaHelium, C, O, Ne, Si burning s-process r-process rp-process νp – process p – process α - process fission recyclingCosmic ray spallation pyconuclear fusion
AZ
fission
(α,γ)
β+ , (n,p)
β-
(p,γ)
(α,p)
(n,2n) (n,γ)
(γ,p)
Sample reaction paths
RHIC Users Meeting June 2013, Slide 45
Black - FRIB critical for modeling
How many isotopes might exist?
Estimated Possible: Erler, Birge, Kortelainen, Nazarewicz, Olsen, Stoitsov, Nature 486, 509–512 (28 June 2012) , based on a study of EDF models
“Known” defined as isotopes with at least one excited state known (1900 isotopes from NNDC database)
Represents what is possible now
RHIC Users Meeting June 2013, Slide 46
The Number of Isotopes Available for Study at FRIB (next generation facilities)
Estimated Possible: Erler, Birge, Kortelainen, Nazarewicz, Olsen, Stoitsov, Nature 486, 509–512 (28 June 2012) , based on a study of EDF models
“Known” defined as isotopes with at least one excited state known (1900 isotopes from NNDC database)
For Z<90 FRIB is predicted to make > 80% of all possible isotopes
RHIC Users Meeting June 2013, Slide 47
A Vision
RHIC Users Meeting June 2013
“It is in my view that continued development and application of radioactive beam techniques could bring the most exciting results in laboratory astrophysics in the next decade”
Nobel Laureate Willy Fowler, 1984
, Slide 48
Unusual Isotopes to Test Fundamental Symmetries – Electric Dipole Moment Search
RHIC Users Meeting June 2013, Slide 49
Wolfgang Korsch
A Electric Dipole Moment, EDM, • Violates CP symmetry• Large value would be evidence for physics beyond the
standard model• Possible explanation for matter dominance over antimatter
Best current limit in nuclei is from WC Griffiths et al. PRL 102, 101601 (2009) d (e-cm) < 3.1 x10-29
Rare isotopes offer the chance for enhanced sensitivity
Current efforts:• 223Rn TRIUMF: E929 Spokespersons T. Chupp (Univ of Michigan), C.
Svensson (Guelph)• 225Ra Argonne National Laboratory: Z-T Lu• 225Ra at TRIμP at KVI
EDM Searches in Three Sectors
Nucleons (n, p)
Nuclei (Hg, Ra, Rn)
Electron in paramagneticmolecules (YbF, ThO)
Quark EDM
Quark Chromo-EDM
Electron EDM
Physics beyond the Standard Model:
SUSY, etc.
Z-T Liu, Univ. of Chicago
RHIC Users Meeting June 2013, Slide 50
Schiff moment of 225Ra, Dobaczewski, Engel (2005)Schiff moment of 199Hg, Ban, Dobaczewski, Engel, Shukla (2010)
Skyrme Model Isoscalar Isovector Isotensor
SIII 300 4000 700
SkM* 300 2000 500
SLy4 700 8000 1000
Enhancement Factor: EDM (225Ra) / EDM (199Hg)
• Closely spaced parity doublet – Haxton & Henley (1983)• Large intrinsic Schiff moment due to octupole deformation
– Auerbach, Flambaum & Spevak (1996)• Relativistic atomic structure (225Ra / 199Hg ~ 3)
– Dzuba, Flambaum, Ginges, Kozlov (2002)
Example: EDM of 225Ra Enhanced
- = (| - | )/2 a b
+ = (| + | )/2a b55 keV
|a |b
Parity doublet
225Ra:I = ½
t1/2 = 15 d
225Ra:I = ½
t1/2 = 15 d
0 0
0 00 0
ˆ ˆˆ . .z i i PT
zi i
S HS S c c
E E
LP Gaffney et al. Nature 497 (2013) 199
RHIC Users Meeting June 2013, Slide 51
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 r-procees (10% of gold from s-process)
We know they must be made in a neutron-rich environment T > 109 K, neutron ≈ 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, however 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 from observational data
More than half of Z>28 from an r-process
RHIC Users Meeting June 2013, Slide 52
Reliable crust models need rare isotope data to interpret observations
Transiently Accreting Neutron Stars Allowthe Study of Dense Matter
RHIC Users Meeting June 2013
KS 1731-260
Bright X-ray burster for ~12 yrAccretion shut off early 2001
Unknown heat sourcewas added
Neutrons drip here?Superfluid?
Core?
Brown & Cumming 2009
MXB 1659-29
Brown&Cumming 2009NASA/Chandra/Wijnands et al.
Cooling profile provide information on the crust
, Slide 53
“Most of the isotopes in use today in practical settings were developed as long as 50 years ago. With few exceptions (e.g., 82Sr and 90Y) there are no new products or services that use isotopes developed in the past 20 years. Without the availability of research isotopes, it is not possible to develop new science or new applications based on isotopes. This problem is extreme in the case of accelerator isotopes …”
Subcommittee FindingIsotopes for the Nation's Future
NSAC Long Range Plan Study 2008
FRIB can provide isotopes for applied science while serving forefront nuclear research
FRIB is designed to provide fast access to a broad range of new isotopes for research
FRIB Will Provide Isotopes Needed for the Nation’s Future
RHIC Users Meeting June 2013 , Slide 54
One of the Challenges: Nuclear Structure
Nucl. Phys. A506 (1990)
http://www.tunl.duke.edu/nucldata/
Hoyle Statetriple α process
See e.g. EFT ofE. Epelbaum et al. PRL 106, 192501 (2011)
Energy [MeV]
RHIC Users Meeting June 2013, Slide 55
12C
α + α + α