GRETINA@ATLAS 1st AGATA-GRETINA Collaboration Meeting Shaofei Zhu Physics Division, Argonne National Laboratory

Physics Opportunities at ATLAS Coulomb Excitation (Stable/CARIBU, CHICO2) Deep Inelastic Reactions and Transfer/Multi-nucleon transfer reactions to study Neutron-Rich Nuclei (Stable/CARIBU, CHICO2/Phoswich Wall) Proton-Drip Line Nuclei (Stable, FMA) At ATLAS – GRETINA with 7 quads and GAMMASPHERE are complimentary devices 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Installation of GRETINA at ATLAS GRETINA support; MSU mechanical supporting structure; Existing LN2 system; Existing Oxygen deficiency alarm and LN2 exhaust; DAQ system; Additional power to room G126; Networks from AREA IV (10 GB) and data room (1GB) to G126; Auxiliary detectors electronics and DAQ systems; Rearranged data room for GRETINA on-line data monitoring workstations; Electronics; Rearranging Gammasphere Shack; No loss of capabilities of running Gammasphere/FMA; Detector Maintenance; Existing detector annealing and testing stations; Existing portable crane; 2016 Low Energy Community Meeting 08/12/2016

Installation of GRETINA at ATLAS GRETINA+CHICOII GRETINA Stand Alone 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Benchmarking Gretina Detectors in the Array Concerns: Clean Ground 7 peaks symmetric; 16 peaks show left tail; 1 drifting peak (2-MeV full scale) bad cable Sum peak at 1332 keV: FWHM = 2.58 keV (Gaussian) FWHM = 2.40 keV (Gaussian+left tail) Full Scale = 2 MeV Full Scale = 5 MeV 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Benchmarking Gretina Detectors in the Array Tail develops with number of fold: 1 fold is symmetric. No neutron damage. 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Gretina Detection Efficiency 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Interfacing with Other Detectors Receive timestamp from Master Trigger via SERDES Latch timestamps when remote detector triggers Provide gating logic as necessary with other NIM or ECL signals Add MγRIAD to remote detector readout so that events have matching timestamps for event building Send remote detector trigger signals to GRETINA Master Trigger for coincidence. 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

CHICO-II and GRETINA 1st AGATA-GRETINA Collaboration Meeting Angular coverage: 12o ≤ θ ≤ 85o, 95o ≤ θ ≤ 168o; 280o in φ Angular resolution: Δθ = 1.6o, Δφ = 2.5o Solid angle: ~69% of 4π Energy-loss output: Improved time, mass and Z resolution Time resolution: Δt ≤ 500ps Mass resolution for kinematic coincidence: Δm/m ≤ 5% Q-value resolution: ≤ 20 MeV Gammasphere γ-ray Doppler broadening: 1.0%* GRETINA γ-ray Doppler broadening: 0.5%* * Average recoil speed around10% of c; Ignores contribution due to intrinsic resolution etc. 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Time between CHICO-II and GRETINA 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Gretina/Gammasphere Coupled to CHICOII Comparison 623 MeV 136Xe on 0.581 mg/cm2 194Pt Particle single rate up to 500 k/s for the scattering angle between 20o and 85o Eg (keV) Dt Eg (keV) Angle Tg (10 ns) 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Gretina/Gammasphere Coupled to CHICOII Comparison Same Beam Energy, Same Target b average = 7.4% Gammasphere Gretina Untracked Gretina Tracked (FOM<=0.8) Gretina Tracked (FOM<=1.0) FWHM: GS: 16.4 keV GT Untracked: 10.4 keV GT Tracked (0.8): 9.7 keV GT Tracked (1.0): 9.7 keV Peak Area Relative to GT Untracked: GS: 1.0 GT Tracked (0.8): 1.26 GT Tracked (1.0): 1.31 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Gretina/Gammasphere Coupled to CHICOII Comparison b average = 4.6% Gammasphere Gretina Untracked Gretina Tracked (FOM<=0.8) Gretina Tracked (FOM<=1.0) 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Accelerated CARIBU beam from ATLAS Experiment Setup for CARIBU Coulomb Excitation Accelerated CARIBU beam from ATLAS γ-ray spectroscopy Particles angles time of flight Monitoring beam Intensities Impurities CHICO2 GRETINA 1.0 mg/cm2 208Pb target PPACs HPGe detector at beam dump g-ray spectrum from b decay Rate determined from number of counts for transitions in daughter nucleus taking into account efficiency and branching ratios Counts Eg (channels) 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

Experimental results for 146Ba 1st AGATA-GRETINA Collaboration Meeting Shaofei Zhu December 5, 2016

Deep-inelastic reactions: Gretina + CHICOII g-ray and isotope correlations reaction partners Δm/m ≤ 5% Q-value resolution:≤ 20 MeV Sensitive to fast transitions proper Doppler corrections Angular distributions FWHM: 6.32 keV at 885 keV (0.71%) 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

GRETINA + Phoswich Wall Experiments No. Pixels: 256 (4 PMT’s) Thin fast-plastic + CsI(Tl) Angle range: 9º ≤ θ ≤ 72º Preferred position: downstream 138Ba+13C Experiment: Coupling w/ Gretina and 9 LaBr3(Ce)’s 1st AGATA-GRETINA Collaboration Meeting Shaofei Zhu December 5, 2016

138Ba + 13C, Elab = 550 MeV (ATLAS) “Online” analysis Particle gates on so-called A-C maps (similar to ΔE-E gating) 139Ba + 12C products (one-neutron transfer) 142Ce + 9Be products (incomplete fusion) 1000 counts 627 particle gate #1 red = 139Ba 455 642 * 100 counts 579 particle gate #2 green = 142Ce 524 * * * * Eγ (keV) * contamination (144Nd) 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

18 PAC-approved experiments 130 days of beam time Shape coexistence in the neutron-rich germanium isotopes 72Ge and 76Ge Octupole Strength in Neutron-Rich Nuclei near A~140: Multi-step Coulomb Excitation of 142,144,146Ba with Reaccelerated CARIBU Beams Shape coexistence in 100Zr studied by low-energy Coulomb excitation Sub-shell closure, proton-neutron symmetry and shape coexistence in 98Zr Precision determination of electromagnetic matrix elements in triaxial110Ru Shape Evolution and Coexistence in the Mo-Ru Region Coulomb Excitation of neutron-rich odd-odd nucleus 98mY Comparison of the performance of the GRETINA and GAMMASPHERE; GRETINA Test: High-Energy Gamma-Ray Performance; Commissioning experiment to study the polarization sensitivity of GRETINA; Fast-timing lifetime measurements in the 13C(138Ba,12Cg)139Ba and 13C(140Ce,12Cg)141Ce reactions Multi-Particle-Hole States in neutron rich 34P Understanding the Low-Energy Enhancement of the Photon-Strength Function in Nuclei 1st AGATA-GRETINA Collaboration Meeting December 5, 2016

ANL Project Personnel M. Albers, J. Anderson, A. Ayangeakaa, M. P. Carpenter, H. David, C. Hoffman, R. Janssens, B. Kay, A. Korichi, T. Lauritsen, T. Levand, D. Potterveld, J. Rohrer, G. Savard, D. Seweryniak, B. Zanbransky, SZ LBNL: C.M. Campbell, H. Crawford, M. Cromaz, P.Fallon, I-Y. Lee, A.O. Macciavelli, A. Wiens NSCL: D. Weisshaar ORNL: J. M. Allmond, D. Radford Unv. Rochester and LLBL(CHICO2): C. Y. Wu, D. Cline, B. M. Bucher, A. Hayes, R. Fox, D. Swan Wash. U. (Phoswich Wall): W. Reviol, D.G. Sarantites, J. Elson, J. Kinnison 1st AGATA-GRETINA Collaboration Meeting December 5, 2016