Decay Spectroscopy Working Group Nuclear Structure Theory Morten Hjorth-Jensen – Shell Structure and Interactions Ivan Borzov – Theory of  Decay Applications of Nuclear Decay Data Hendrik Schatz – Nuclear Astrophysics (r-process) Ian Gauld – Nuclear Reactors, Safeguards, and National Security Key Nuclear Structure Experiments and Equipment at Upgraded HRIBF 78 Ni Region: Chiara Mazzocchi 132 Sn Region: Agnieszka Korgul and Jon Batchelder Nuclear Level Lifetimes: Volker Werner and Henryk Mach Proton drip-line and SHE studies with SIBs and RIBs – Robert Page Neutron Detection: Miguel Madurga Electron Counting: Ed Zganjar Total Absorption Gamma Spectroscopy: Marek Karny High Resolution and Efficiency Gamma Counting: Sean Liddick High Resolution Isobar/Isomer Separator: Andreas Piechaczek Storage Ring: Robert Grzywacz

Nuclear Shell Structure and Interactions – M. Hjorth-Jensen 48 Ni – 56 Ni – 68 Ni – 78 Ni 100 Sn – 114 Sn – 116 Sn – 132 Sn – 140 Sn Experimental Benchmark for many-body forces Deformation: Density Functional Theory

Theory of  Decay – I. Borzov I.N. Borzov, PRC 71(2005) C70 Reach I.N. Borzov, NPA777(2006)645 J.A. Winger et al., PRL 102 (2009)

Nuclear Astrophysics – H. Schatz “… our current simulation is far from reproducing the solar r-process signature. […] One reason for this could well be the uncertainties in the  -decay rates.” (Fryer et al. 2006) --> Great opportunities at upgraded ORNL ISOL facility for a major step in probing (and understanding) the r-process Reach the point where the models can no longer blame nuclear physics for the inability to get the correct result.

Nuclear Reactors, Nuclear Safeguards, and National Security – I. Gauld OECD/NEA WPEC 25 Decay Heat Analysis International Working Party on Evaluation Co-operation of the NEA Nuclear Science Committee NEA/WPEC-25 VOLUME 25 - Assessment of Fission Product Decay Data for Decay Heat Calculations Important to – – Reactor LOCA analysis – Delayed gamma analysis from active neutron interrogation Known issues with evaluations WPEC-25 developed a priority list of isotopes for re-measurement Electromagnetic decay heat following thermal fission burst of 239 Pu

Decay studies of neutron-rich nuclei at Range out experiment LeRIBSS experiment +/-40 keV +/-160 keV Isobar separator M/  M ~ Mass separator M/ΔM ~ MeV protons ~ 10  A 2-3 MeV/u 200 keV charge exchange cell (removes Zn, Cd) ~ 5% efficiency Positive ions Positive or negative ions Tandem accelerator (negative ions only) ~ 10% efficiency IRIS-1 ORIC : ~6 g 238 U fission fragments ~10 11 /s         ~20%   ~60% gas cell Energy loss Total ion energy 76 Cu 76 Ga 76 Ge no 76 Zn !!! Range out exp gas cell spectra C.J.Gross et al., EPJ A25,115,2005 C70-like cyclotron ~  A, 70 MeV ~10 13 /s g 238 U MCP

HRIBF HDU Experiments R. Page V. Werner J.C. Batchelder C. Mazzocchi A. Korgul

Decay studies : HRIBF as a world-unique ISOL facility very high rates + isobaric separation + ion “ranging-out” and tagging + powerful detectors and digital data acquisition and the collaborations of contributing users ! photo-peak efficiency total  -efficiency MTAS M. Karny  Detector E. Zganjar 3Hen LSU/MS State/ UTK/ORNL ORISS (  M/M 1:400,000) A.Piechaczek ekta-BESCA E. Zganjar VANDLE M. Madurga CERDA S.N. Liddick

Summary There are important issues in nuclear structure, nuclear astrophysics, nuclear reactors and safety, and national security which require information from  decay. The HRIBF has a unique ability to provide highly purified radioactive beams with event-by-event measured intensity. The HRIBF currently has a powerful array of detector systems in place for this research A number of new detector systems are being built which will further enhance the HRIBF research ORISS will add to the ability to provide pure beams The HRIBF Hadron Driver Upgrade will provide a significant increase in the range and number of key decay experiments which can be performed. The HRIBF HUD will bridge the gap in high-power ISOL research in the US until CD4 FRIB. The results from the upgraded HRIBF will create a database for the discussion of ISOL vs. second fragmentation target options at FRIB.