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Overview

Overview. Gamma-ray Spectroscopic Studies of Exotic Nuclei: Towards NuSTAR Mike Bentley (University of York, UK). Outline: UK role in NuSTAR at FAIR Physics Highlights in “pre-cursor” fragmentation campaigns Towards NuSTAR. What are the limits for existence of nuclei?

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Overview

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  1. Overview Gamma-ray Spectroscopic Studies of Exotic Nuclei: Towards NuSTAR Mike Bentley (University of York, UK) • Outline: • UK role in NuSTAR at FAIR • Physics Highlights in “pre-cursor” fragmentation campaigns • Towards NuSTAR NuPECC Meeting - Bentley

  2. What are the limits for existence of nuclei? Where are the proton and neutron drip lines situated? Where does the nuclear chart end? How does the nuclear force depend on varying proton-to-neutron ratios? What is the isospin dependence of the spin-orbit force? How does shell structure change far away from stability? How to explain collective phenomena from individual motion? What are the phases, relevant degrees of freedom, and symmetries of the nuclear many-body system? How are complex nuclei built from their basic constituents? What is the effective nucleon-nucleon interaction? How does QCD constrain its parameters? Which are the nuclei relevant for astrophysical processes and what are their properties? What is the origin of the heavy elements? NuSTAR @ FAIR NUclear STructure Astrophysics and Reactions NuPECC Meeting - Bentley

  3. NuSTAR @ FAIR The FAIR/NuSTAR facility What is NuSTAR? Project launched on November 7, 2007 NuPECC Meeting - Bentley

  4. NuSTAR @ FAIR Key features: High intensity High Energy High Purity NuPECC Meeting - Bentley

  5. NuSTAR – UK role Funding update: UK committed to funding for NuSTAR and PANDA at FAIR NuSTAR: £11M from Research Councils + Universities NuPECC Meeting - Bentley

  6. Towards NuSTAR (@ GSI) Present Physics with Fragmentation Beams 2014 NuPECC Meeting - Bentley

  7. N=Z T1/2 = 10.4 s 205Au126 Proton-Rich Decay Spectroscopy K-electrons L-electrons 202Pt NuPECC Meeting - Bentley

  8. Example: RISING at GSI RISING Rare Isotopic Spectroscopic INvestigations @ GSI = 15 x Cluster germaniums for (the most) exotic gamma-ray spectroscopy NuPECC Meeting - Bentley

  9. Stopped-beam RISING at GSI Fragment Separator (FRS) Focal Pane ID Stopped RISING See, e.g. Regan et al, Nucl. Phys. A 787 (2007) 491 • Chemically independent production mechanism for secondary • radioactive beams. • Time of flight from production to stopper ~x00ns. • Some ions transmitted in metastable states. NuPECC Meeting - Bentley

  10. 54Ni spectroscopy at RISING D.Rudolph et al, Phys. Rev. C78 (Rap. Comm) (2008) 021301 Delayed Gamma-rays after implantation 550 MeV/u 58Ni fragmented on 1g/cm2 Be target NuPECC Meeting - Bentley

  11. 54Ni spectroscopy at RISING 28262628 D.Rudolph et al, Phys. Rev. C78 (Rap. Comm.) 2008 021301 PRL 97 (2006) 152501 NuPECC Meeting - Bentley

  12. The J=2 Anomaly Charge Symmetry Breaking – spin dependence (J=2 Anomaly) Decreasing overlap of two nucleons coupled to increasing spin J Warner, Bentley, Van Isacker, NATURE Physics 2 (2006) 311. A=54 MED Gadeaet al, Phys. Rev. Lett 97 (2006) 152501 Observed A=54 MED Expected MED (2 holes) D.Rudolph et al, Phys. Rev. C78 (2008) 021301(R) NuPECC Meeting - Bentley

  13. Spectroscopy of odd-odd N=Z nuclei: RISING at GSI A.B.Garnsworthy et al, Phys. Lett. B 600 (2008) 326 750 MeV/u 107Ag fragmented on 4g/cm2 Be target NuPECC Meeting - Bentley

  14. Spectroscopy of odd-odd N=Z nuclei: RISING at GSI NuPECC Meeting - Bentley

  15. Spectroscopy of odd-odd N=Z nuclei: RISING at GSI A.B. Garnsworthy et al., Phys. Lett. B660, 326 (2008) NuPECC Meeting - Bentley

  16. T1/2=10.4 s K-electrons L-electrons 205Au126 T1/2Weiss(E3(94)) = 7.49 s T1/2Weiss(M4(921)) = 10.6 s Eg(exp)(11/2-3/2+) = 912 keV 204Pt126 T1/2 = 10.4 s 205Au126 K-electrons L-electrons 202Pt N=82 N=126 NuPECC Meeting - Bentley

  17. Quenching of N=82 and N=126 gaps? exp. pronounced shell gap shell structure quenched r-process abundances mass number A information on excited states essential!! Assumption of N=82 and N=126 shell quenching leads to a considerable improvement in the global abundance fit in r-process calculations NuPECC Meeting - Bentley

  18. Decay Spectroscopy around N=126 gap: RISING 208Pb at 1 GeV/u on 2.5 g.cm2 Be target 205Au 204Pt ? Experiment led by Zs. Podolyák, Surrey Within red line: nuclei populated and measured by RISING. NuPECC Meeting - Bentley

  19. Decay Spectroscopy around N=126 gap: RISING S.Steeret al. submitted to PRL, Mar. 08 NuPECC Meeting - Bentley

  20. Decay Spectroscopy around N=126 gap: RISING Observation of isomers -> change in shell-model parameters NuPECC Meeting - Bentley

  21. Decay Spectroscopy at NuSTAR: DESPEC Decay spectroscopy (DESPEC) In-flight spectroscopy (HISPEC) Energy buncher / spectrometer NuPECC Meeting - Bentley

  22. r-process nucleosynthesis Nuclear Astrophysics -delayed neutron decay Nuclear Structure -delayed proton decay Fundamental symmetries high spin isomeric decay -decay spectroscopy Gamov-Teller quenching superallowed Fermi transitions Decay Spectroscopy at NuSTAR: DESPREC ,  , ,p, n detection and spectroscopy: lifetimes, energies, strengths, spins  and p  and n NuPECC Meeting - Bentley

  23. In-beam Spectroscopy: Fragmentation at MSU 10pnA 58Ni 600 mg/cm2 Be target 0.5 -1.0 × 106 pps (70% 56Ni) 188 mg/cm2 Be S800 Spectrograph NSCL Experiment #5117, March 2007 – Bentley et al NuPECC Meeting - Bentley

  24. In-beam Spectroscopy: Fragmentation of 56Ni J.R. Brown et al. (YORK) in prep (2008) S800 – Fragment ID Drip line Z A/Q NuPECC Meeting - Bentley

  25. In-beam Spectroscopy: N=Z-3 Nuclei 53Ni, 49Fe J.R. Brown et al. (YORK) in prep (2008) 53Mn First spectrsocopy of N=Z-3 nuclei above 33Ar 53Ni 49V SeGA in-beam Gamma-ray spectra 49Fe NuPECC Meeting - Bentley

  26. In-beam Spectroscopy: N=Z-3 Nuclei 53Ni, 49Fe J.R. Brown et al. (YORK) in prep (2008) Energy Difference (keV) Strong evidence for J=2 Anomaly... NuPECC Meeting - Bentley

  27. In-beam Spectroscopy at NuSTAR: HISPEC Decay spectroscopy (DESPEC) In-flight spectroscopy (HISPEC) Energy buncher / spectrometer NuPECC Meeting - Bentley

  28. High Resolution In-beam SPECtroscopy: HISPEC Rare Isotope Beams of all elements Relativistic Beams 100 MeV/u Super-FRS, low energy buncher Beam: T1/2 ≤ 200 ns, E  0.1-0.3 % Fast slowed down beams 3-20 MeV/u Super-FRS, low energy buncher Beam: T1/2≤ 200 ns, E  10-30 %, beam tracking required Brilliant low energy beams 3-20 MeV/u Super-FRS, NESR, transfer line Beam: T1/2 > 5 s, E  0.01 %, Ilim≤107/s isomer beams • Coulomb excitation • Knock out ractions • Fragmentation • Multiple Coulomb excitation • Transfer reactions • Inelastic reactions • Fusion reaction NuPECC Meeting - Bentley

  29. Reactions with Relativistic Radioactive Beams: R3B RIB Reactions in complete kinematics High Resolution measurement • Target • Tracker • Calorimeter Neutrons Protons Heavy fragments Large acceptance dipole NuPECC Meeting - Bentley

  30. Reactions with Relativistic Radioactive Beams: R3B High-energy RIBs (200 – 2000 A.MeV) Unique capability to investigate fundamental aspects of isospin asymmetric nuclei and nuclear matter • Structure of asymmetric nuclei • modification of independent particle model • correlations in nuclei • new collective modes • Bulk properties of asymmetric nuclear matter • nuclear EOS • density dependence of symmetry energy • in-medium NN cross-sections neutron skin  core vibration NuPECC Meeting - Bentley

  31. Summary • Gamma-ray spectroscopy of Exotic nuclei through projectile fragmentation... • Proton-rich: Limits of nuclear stability, breakdown of isospin symmetry, exotic decay modes • Neutron-rich: Evolution and quenching of shell gaps • Current experiments pave the way for NuSTAR Thanks to: GSI (RISING Community) MSU (Glasmacher, Gade, Bazin et al) HISPEC/DESPEC Community Paddy Regan, ZsoltPodolyak (Surrey) NuPECC Meeting - Bentley

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