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Scientific Program of the Facility for Rare Isotope Beams

Scientific Program of the Facility for Rare Isotope Beams. December, 2011 Bradley M. Sherrill FRIB Chief Scientist. Introduction. There is a broad scientific program associated with the production of rare isotopes – overview in this talk; more details in other talks

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Scientific Program of the Facility for Rare Isotope Beams

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  1. Scientific Program of the Facility for Rare Isotope Beams December, 2011 Bradley M. Sherrill FRIB Chief Scientist

  2. Introduction • There is a broad scientific program associated with the production of rare isotopes – overview in this talk; more details in other talks • Science goals pursued in many countries at laboratories world wide – exciting time for this field • The next generation facilities (RIKEN, TRIUMF ARIEL, SPIRAL2, FAIR, FRIB, KoRIA) will make a major next step • KoRIA and FRIB have a difference technical focus, but the science programs (same for all facilities) are in principle similar – likely the mix of nuclear, astrophysics, particle, condensed matter, etc. will be different • Science of FRIB

  3. Broad Overview of the FRIB Program Properties of nuclei • Develop a predictive model of nuclei and their interactions • Understand the origins of the nuclear force in terms of QCD • Many-body quantum science: intellectual overlap to mesoscopic science, quantum dots, atomic clusters, etc. Astrophysical processes • Chemical history of the universe; use this for stellar archaeology • Model explosive environments • 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 • Biology, medicine, energy, material sciences, national security

  4. FRIB Users Organization • Potential users register as members of the independent FRIB Users Organization, FRIBUO • Chartered organization with an elected executive committee (Chair is Michael Smith, ORNL; members – Aprahamian, Blackmon, Casten, Gade, Macchiavelli, Savard, Wiedenhoever, Wuosmaa) • 15 January 2010 began registration • We presently have about 1050 members • The FRIBUO has 21 working groups centered on equipment and theoretical development – SAC provides feedback • 8 Related Workshops since 2009 • FRIB Theory Organization has joined with the FRIBUO http://fribusers.org/ Feb 2010 FRIB equipment workshop

  5. The Nuclear Landscape Roadmap: Chart of Nuclides We don’t know this limit. We don’t know this limit. Green closed area is the region of isotopes observed so far. We can’t say with precision where or when the atoms fond in nature were made. We don’t know this limit. Black squares are the around 260 stable isotopes found in nature (> 1 Gy)

  6. Production of Rare Isotopes by Projectile Fragmentation (not the only method) • Cartoon of the production process – projectile fragmentation (or fission) • To produce a key nucleus like 122Zr from 136Xe, the production cross is estimated to be 2x10-18b (2 attobarns, 2x10-46 m2 ) • Nevertheless with a 136Xe ≅ 8x1013 ion/s (400 kW at 200 MeV/u) a few atoms per week can be made and studied • For comparison: Element 117 production cross section was 1.3 (+1.5 -0.6) pb (Oganessian, Yu. Ts. et al. Phy Rev Lett 104 (2010) 142502) • Few x10-46 m2 is on the order of 100 MeV neutrino-electron elastic scattering cross sections projectile target

  7. Weakly bound isotopes have unique features • Large neutron skins • Modified mean field • Resonance properties Halo Tanihata PRL1985 protons Skin Tanihata PLB1992 neutrons 80Ni 11Li New 220Rn Science: Pairing in low-density material, new tests of nuclear models, open quantum system, interaction with continuum states - Efimov States - Reactions

  8. The Reach of FRIB • FRIB is estimated to produce more than 1000 NEW isotopes at useful rates (5000 available for study; compared to 1700 now) • Exciting prospects for study of nuclei along the drip line to A=120(compared to A=24) • Production of most of the key nuclei for astrophysical modeling • Theory is key to making the right measurements and interpreting them Rates are available at http://groups.nscl.msu.edu/frib/rates/

  9. Facility for Rare Isotope Beams, FRIBMichigan State University Campus

  10. US Community’s Major New Initiative – Facility for Rare Isotope Beams • Laboratory Director Konrad Gelbke, Project Director Thomas Glasmacher • Estimate of TPC $614.5M • Project completion in 2020, early completion in 2018 (CD2/3A Review in April 2012) – NSCL operational now • Key features (unique) • 400 kW heavy ion beams • Stopped and reaccelerated, separated beams • Space for • Reaccelerated beams, uranium to 12 (15) MeV/u • Isotope harvesting • Focus on rare isotope beams – no stable beam research is planned FRIB

  11. FRIB Driver Linear Accelerator Superconducting RF cavities 4 types ≈ 350 total Eacc≈ 6-9 MV/m β=0.04 β = 0.08 β = 0.29 β = 0.53

  12. FRIB Facility Layout

  13. Science-driven Upgrade Options Remain Experimental Areadouble space if science needs it Light ion injector upgrade 3He+, 195 MeV/u Energy upgrade to ≥ 400 MeV/u for all ions(high performance λ/2 cryomodules) ISOL targets 3He, 400 MeV/u Multiuser capability with light ion injector

  14. The Big Picture: Understanding the Nuclear Force Goal: Model and accurately describe nuclei and their reactions. The ability to calculate reactions like 7Be(p,g) (responsible for source of neutrinos from the core of the Sun) from first principles would be transformational. Theory Roadmap – 2007 NSAC Long Range Plan • Step 1: Use ab initiotheory (like no-core shell model) and study of exotic nuclei to determine the interactions of nucleons in light nuclei and connect these to QCD by comparison to lattice calculations of NN and NNN forces • Step 2: For mid-mass nuclei use configuration space models. The degrees of freedom and interactions must be determined from exotic nuclei • Step 3: Use density functional theory to connect to heavy nuclei. Exotic nuclei help determine the form and parameters of the DFT. Step 3 is the one that is likely to answer the question about what are the heaviest elements.

  15. Ab initio Approaches to Forces in Nuclei • Understanding the nuclear force from QCD is complicated and difficult • Approach: Construct NN potentials based on neutron and proton scattering data and properties of light nuclei (Bonn, Reid, Illinois AV18, Nijmegen, etc.) • Nuclei have even more complications since nucleons have structure and three-body forces are also important (four-body, …) • Use properties of rare isotopes to determine effective 3N, 4N, etc. forces and test the validity of models • Other issues: modified nucleons, isospin violation, etc. Ishii, Aoki, Hatsuda, Phys. Rev. Lett. 99, 022001 (2007)

  16. Comparison of Calculated and Measured Binding Energies with NN models • Greens Function Monte Carlo techniques allow up to mass number 12 to be calculated • Example blue 2-body forces V18 • S. Pieper B.Wiringa, et al. NN potential NN + NNN potential

  17. 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 • S. Pieper B.Wiringa, et al. NN + improved NNN potential Properties of exotic isotopes are essential in determining NN and NNN potentials

  18. Application of GFMC technique to reactions of nuclei • Resonance states in 5He (n+4He) K. Nollett, et al, PRL 2007; motivated by BBN modeling

  19. Next Steps: EFT based on QCD Symmetries – “Chiral” • Use the features of the pion in constructing an effective theory Cut-off parameter Λ ≅ 500MeV Contact interactions have constants that are fit to experiment Picture from E. Epelbaum Effective Field Theory, EFT, based on QCD Symmetries (Weinberg,Epelbaum ,Furnstahl, Machleidt, van Kolck, Navrátil,… )

  20. Changes in Shell Structure – The Traditional Nuclear Shell Model is Incomplete Traditional Shell Picture Possible origins - Weak binding, tensor force, three-body force, …

  21. Tensor Force • T Otsukaet al. has shown the importance of a monopole part of the tensor force in nuclei (Otsuka et al. PRL 2001, 2005, 2010) • Related to single pion exchange (Yukawa 1935) • This modifies the standard shell picture 40Ca 26O

  22. Density Functional Theory • The idea was introduced in atomic physics (Kohn) and is widely used in Chemistry (calculation of molecular properties as good as experiment) • Relies on the variation concept where observables are treated as variational parameters, e.g. local density ρ(r) • Minimize the variational equation δ(E(ρ) – ∫ V(r)ρ(r) dr) = 0, E=<Ĥ> • Two step procedure • Equation ensures that the total energy is minimized at a fixed ρ(r) • Minimization of E(ρ(r)) with ρ(r) gives the exact ground state energy and the exact value of ρ(r) for the ground-state wave function • Example: Skyrmefunctional • Comparison with rare isotope measured masses shows this is incomplete from S Bogner

  23. Broad View of Nuclear Properties Goal: produce a more comprehensive picture of the nuclear landscape Measurements of • masses • moments • deformations • transition rates • single particle strengths • 2+/4+systematics • fission barriers • etc.

  24. Goals of Nuclear Astrophysics • Understand the origin and history of atoms in the Universe • Model the chemical history of the Milky Way • Trace the chemical history of the Universe back to the first stars • Learn about the early Universe from what atoms were produced in the Big Bang • Use the chemical nature of a star, cluster or galaxy to infer something about its origin and history • Allow accurate modeling of astrophysical objects and allow observations to be used to infer conditions at the site • For example, using the light as a function of time (called a light curve) of an X-ray burst to determine the size of emitting region. • Use observations to tell us about extreme environments in the universe; neutron stars, supernovae, novae, black holes, the Big Bang, etc.

  25. Forefront of Observational Astronomy: High Resolution Telescopes Hubble Space • 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, SEGUE, 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.” Large Binocular Telescope

  26. There are a number of nucleosynthesis processes that must be modeled • 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 Sample reaction paths fission (α,γ) (p,γ) β- (α,p) AZ (n,2n) (n,γ) β+ , (n,p) (γ,p)

  27. Known half-life N=126 NSCL reach RISACKey Nuclei First experiments (70) Yb (69) Tm (68) Er Future Reach (67) Ho (66) Dy 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 FRIB reachfor (d,p) 126 50 Current reach 82 28 FRIB reach forhalf-lives 50

  28. FRIB Reach for Novae and X-ray burst reaction rate studies rp-process 10>10 109-10 108-9 107-8 direct (p,g) 106-7 direct (p,a) or (a,p)transfer key reaction rates can beindirectly measuredincluding 72Kr waiting point 105-6 (p,p), some transfer 104-5 102-4 most reaction rates up to ~Sr can bedirectly measured All reaction rates up to ~Ti can be directly measured H. Schatz

  29. Tests of Nature’s Fundamental Symmetries • Angular correlations in β-decay and search for scalar currents • Mass scale for new particle comparable with LHC • 6He and 18Ne at 1012/s • Electric Dipole Moments • 225Ac, 223Rn, 229Pa (30,000x more sensitive than 199Hg; 229Pa > 1010/s) • Parity Non-Conservation in atoms • weak charge in the nucleus (francium isotopes; 109/s) • Unitarity of CKM matrix • Vud by super allowed Fermi decay • Probe the validity of nuclear corrections e γ 212Fr Z

  30. 8Li β-NMR Resonance Studies • Developed at TRIUMF (RF Kiefl, G Morris, et al.) • Sensitivity 1013 higher than NMR • Limited by availability of facilities • Example: Study of Mn12 single molecule magnets on Si Surface Z. Salmanet al. NanoLett. 7 (2007) 1551

  31. Isotopes in Medicine -Targeted Cancer Therapy • Harvest Isotopes in parallel to normal prodction • Modern targeted therapies in medicine take advantage of knowledge of the biology of cancer and the specific biomolecules that are important in causing or maintaining the abnormal proliferation of cells • These radionuclides have been relatively difficult to get in sufficient quantities1. The short-lived alpha emitters are particularly in demand, especially 225Ac, 213Bi, and 211At. • Pairs, e.g., 67Cu (treatment) and 64Cu (dosimetry) are particularly interesting • FRIB can parasitically supply demand for many isotopes 1Isotopes for the Nation’s Future: A Long Range Plan , NSACIS 2009

  32. Sample Interesting Isotopes from FRIB and uses • 2010 Santa Fe Workshop on Applications of Isotopes from FRIB

  33. Examples of Scientific Goals of FRIB that Drive Specifications • The science requires stopped (trap experiments), reaccelerated (precision nuclear spectroscopy), fast (sensitivity) beam experiments. • Example: FRIB intensity will allow the key benchmark nuclei 54Ca (reaccelerated beams) and 60Ca (fast beams) to be studied • The high primary beam power of 400 kW is key to producing sufficient quantities of key nuclei

  34. Notional FRIB Experimental Equipment Layout Astro (< 3MeV/u) Stopped Beams (traps,lasers) Nuclear Large acceptance Neutron detection S800 Decay studies Fast Beams

  35. Summary • We have entered the age of designer atomic nuclei – new tool for science • Current and next generation facilities will allow production of a wide range of new designer 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 source for research quantities of exotic isotopes • Stay tuned there are likely many surprises we will find along the way

  36. Cackett et al. 2006 (Chandra, XMM-Newton) Rare Isotope Crusts of Accreting Neutron Stars KS 1731-260(Chandra) • 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…) H. Schatz

  37. FRIB Reach For Crust Processes Known mass Electron capture rates Mass measurements Drip line established Haensel & ZdunikAstroJourn1990, 2003, 2008 Gupta et al.AstroJourn 2006 • Interesting set of reactions leading to proton-rich material converted to neutron-rich material H. Schatz

  38. Nuclear Astrophysics • How has the chemical abundance of galaxies changed with time? • What were the first stars in the Universe like? • What does the elemental abundance pattern in a star tell us about its history? • How many times have atoms been recycled to result in the chemical pattern of our Sun? Hubble Space Telescope image of the face-on spiral galaxy Messier 101 (M101)

  39. A Challenge for Nuclear Science • We want to model physical phenomena that are the result of the strong force • This includes understanding atomic nuclei, hadrons, QGP, … • We have made remarkable progress in modeling hadrons – Nobel prize in 2004 Gross, Politzer, Wilczek ; LQCD calculation of nucleon and meson masses (Dürr, Fodor, Lippert et al., Science 322 (2008)) • There is room for significant progress in understanding atomic nuclei • Illustration from David Dean JPARC FAIR JLAB Rare isotopes

  40. Current status of the GFMC calculations Carlson, Pieper, Wiringa, et al.

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