Coupling ORRUBA and GRETINA Coupling ORRUBA and GRETINA Steven D. Pain Oak Ridge National Laboratory • ORRUBA • Coupling with GS • Coupling with GRETINA • Instrumentation GRETINA Workshop, ANL, February 2013
Dec 15, 2015
Coupling ORRUBA and GRETINACoupling 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 GRETINACoupling 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 ArrayOak 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 (1000m R + 65m NR)
– > 90°: 12 detectors (500m R)
• ORRUBA gives ~80% coverage over = 45° → 135°
• 288 electronics channels
ORRUBA Detector DesignORRUBA Detector DesignE
nerg
y Lo
ss (
MeV
)
1.0
2.0
3.0
4.0
5.0
0.05.0 15.010.0
Residual Energy (MeV)
p
d
GODDESSGODDESS
New end-cap detectors under design
1 deg (polar) resolution over most angles
15 to 165 degree coverage (>75%)
Polar angle coverage
GODDESS Channel CountGODDESS 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
(136 - 384 ch)
Backward hemisphere = 260 ch Forward hemisphere = 356 - 604 ch
GRETINA performance for light-ion transfer reactionsGRETINA 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
138Xe(d,p) 138Xe(d,t)
~0.5 deg (0.05 deg) ~ 1 deg (~0.1 deg)
~3% ~3%
0.01% 0.01%
2 keV 2 keV
2 deg 2 deg
Gammasphere ~13 keV GRETINA ~3 keV
ORRUBA + GRETINA Physical CouplingORRUBA + GRETINA Physical Coupling
Fits inside standard (DGS) GRETINA chamber
Marginally tighter squeeze inside GS
Room to bring out electronics?
InstrumentationInstrumentation
FMA Focal Plane DSSD electronics
320 channels
ORNL electronics
~300 channels
Backward hemisphere = 260 ch
Forward hemisphere = 356 - 604 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 testsNovember 2011 – ANL tests
November 2011 – ANL testsNovember 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)228Th source for calibration of the ORRUBA detectors, and 249Cf was used to perform an - coincidence measurement
Instrumenting Resistive StripsInstrumenting Resistive Strips
0.5s 1.0s 1.5s
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 digitizers
SummarySummary
AcknowledgementsAcknowledgements
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 StripsInstrumenting Resistive Strips
BA
A = Shaping time too short
B = Shaping time better matched
Position Position
Ene
rgy