Coupling ORRUBA and GRETINA Steven D. Pain Oak Ridge National Laboratory ORRUBA Coupling with GS Coupling with GRETINA Instrumentation GRETINA Workshop, ANL, February 2013

Coupling ORRUBA and GRETINA Steven D. Pain Oak Ridge National Laboratory GRETINA Workshop, ANL, February 2013 ORRUBA Coupling with GS Coupling with GRETINA Instrumentation

Oak Ridge Rutgers University Barrel Array Barrel array of ion-implanted silicon strip detectors Custom resistive design used to achieve good position resolution (~1mm) without requiring 1000s of electronics channels 2 rings –  < 90°: 12 telescopes (1000  m R + 65  m NR) –  > 90°: 12 detectors (500  m R) ORRUBA gives ~80%  coverage over  = 45° → 135° 288 electronics channels

ORRUBA Detector Design Energy Loss (MeV) Residual Energy (MeV) p d

GODDESS G ammasphere O RRUBA: D ual D etectors for E xperimental S tructure S tudies

GODDESS New end-cap detectors under design 1 deg (polar) resolution over most angles 15 to 165 degree coverage (>75%) Polar angle coverage

GODDESS Channel Count Total preamplifers = 720 ch (complete coverage requires 616 ch) One ring 1-layer (132 ch) One ring telescopes (220 ch) Endcap 1 layer (128 ch) Endcap 3-stack ( ch) Backward hemisphere = 260 ch Forward hemisphere = ch

GRETINA performance for light-ion transfer reactions Recoil direction Recoil energy (target thickness) Recoil energy (reaction) Intrinsic resolution of Ge detector Measured angle of gamma ray 138 Xe(d,p) 138 Xe(d,t) ~0.5 deg (0.05 deg)~ 1 deg (~0.1 deg)~3% 0.01% 2 keV2 deg Gammasphere ~13 keV GRETINA ~3 keV

ORRUBA + GRETINA Physical Coupling Fits inside standard (DGS) GRETINA chamber Marginally tighter squeeze inside GS Room to bring out electronics?

ORRUBA + GRETINA Physical Coupling

Instrumentation FMA Focal Plane DSSD electronics 320 channels ORNL electronics ~300 channels Backward hemisphere = 260 ch Forward hemisphere = ch Complete coverage = 616 ch and up Conventional instrumentation FMA Focal Plane DSSD electronics 320 digitizers + GRETINA aux channels? + DGS? Digital instrumentation

> 5 feet Pre-amplifiers mounted on top of “chimney” Required some 6 feet of signal cable before any amplification Ineffective shielding between feed-through and preamplifiers Led to resolution degradation over usual performance (~ 30% effect) November 2011 – ANL tests

Signals run the length of the FMA (2 x 25 ft cables) Instrumented with RAL shaping amplifiers, and CAMAC ADCs of Darek Sewerniak Digital Analog Data also taken with Darek’s GRETINA digitizers (14 bit, 100 MHz) 228 Th source for calibration of the ORRUBA detectors, and 249 Cf was used to perform an  -  coincidence measurement

Instrumenting Resistive Strips 0.5  s1.0  s1.5  s Energy and position filters?

ORRUBA fits within GRETINA chamber Coupling with Gammasphere underway –Hardware built –New end-cap detectors Most of GODDESS setup could be equally used with GRETINA –In standalone mode, or if there was sufficient distance to the FMA quad –Radial alternatives possible (would require more hardware fabrication, and longer un-amplified signal cables) Combination of ORRUBA and GRETINA could give excellent (few keV) energy resolution Both conventional ADC or digitized readout of ORRUBA are options –Sufficient conventional channels exist –Performance benefits to using digitizersSummary

Acknowledgements Callum Shand keeping out of the Texas heat Steven Hardy – proud of his detector mounts Andrew Ratkiewicz – not entirely convinced by the dinosaurs at the creation museum Thanks also to the UTK machine shop, Darek Sewerniak, Mike Carpenter, Shaofei Zhu and Kim Lister…. Postdoc MPhys student

Instrumenting Resistive Strips BA A = Shaping time too short B = Shaping time better matched Position Energy

Instrumenting Resistive Strips 0.5  s1.0  s1.5  s Energy and position filters?