FRIB Physics Program

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)


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)


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


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.


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)


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


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.


Current status of the GFMC calculations

Carlson, Pieper, Wiringa, et al.


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


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.


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


Standard Shell Model


Mayer and Jensen Nobel prize in 1963 “"for their discoveries concerning nuclear shell structure"

picture Niels WaletN l2 potential Spin-Orbit

Magic Numbers

http://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=AZndpSB86zIWcM&tbnid=eHGzyJAkX-AFfM:&ved=0CAUQjRw&url=http://oer.physics.manchester.ac.uk/NP/Notes/Notes/Notesse23.xht&ei=JiDDUbenJIn_qwHb24GYCQ&bvm=bv.48175248,d.aWM&psig=AFQjCNGoqAgxeVMhwzRT4re8A-YYymxxAA&ust=1371828639255842

Stability of Magic Nuclei


Harder to excite

, Slide 16

Stability of Magic Nuclei


Harder to excite

20 protons

16 protons

14 protons

, Slide 17

Surprise: Changing Magic Numbers


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


N. Schunck, Exotic Beam Summer School 2012

Prediction of the limits of the nuclear landscape


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)


“Normal”

Weakly Bound Nuclei are Open Quantum Systems


Dobaczewski et al., Prog. Part. Nucl. Phys. 59, 432 (2007)

W Nazarewicz


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


SUBARU

Simulation of Solar System Abundances

Timmes, Woosley, Weaver Astro. Journal 1995

Success ! ? Note above A=72 we can’t model


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-


…


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


H. Schatz


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


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


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

http://www4.nau.edu/meteorite/Meteorite/Book-GlossaryX.html


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


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



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


• 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


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


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


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


“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)


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


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


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


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


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


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


A Vision


“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


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


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


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


Reliable crust models need rare isotope data to interpret observations

Transiently Accreting Neutron Stars Allowthe Study of Dense Matter


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]


12C

α + α + α

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