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

2. 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

3. 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

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

5. 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

6. 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

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

8. 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

9. CHICO-II and GRETINA 1st AGATA-GRETINA Collaboration Meeting
Angular coverage:
12o ≤ θ ≤ 85o, 95o ≤ θ ≤ 168o; o 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

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

11. Gretina/Gammasphere Coupled to CHICOII Comparison
623 MeV 136Xe on 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

12. 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

13. 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

14. 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

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

16. 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

17. 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

18. 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

19. 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

20. 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