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WP2 summary of activities at Oxford. Dr B Camanzi On behalf of the University of Oxford Group. Outline. Experimental set-up SiPM characterisation Timing resolution studies Summary. Equipment: SiPMs and crystals. Experimental set-up.
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WP2 summary of activities at Oxford Dr B Camanzi On behalf of the University of Oxford Group
Outline • Experimental set-up • SiPM characterisation • Timing resolution studies • Summary ENVISION WP2 Meeting Lyon 03/02/11
Equipment: SiPMs and crystals ENVISION WP2 Meeting Lyon 03/02/11
Experimental set-up • Two-channel demonstrator: Hamamatsu 3x3mm2 50 mm + LaBr3(Ce) • 22Na source • Electronics: • Preamps boards from Photonique: ~700ps rise time, gain 10x-20x • Keithley 2612A two-channel Sourcemeter 200V • DAQ: LeCroy WavePro 725Zi 2.5GHz oscilloscope Scope Keithley 22Na source Two-channel demonstrator system ENVISION WP2 Meeting Lyon 03/02/11
Studies carried out so far • SiPM characterisation • I-V curves and breakdown voltages • Rise time measurements • Single photon signal • Timing resolution studies of a two-channel demonstrator: • Timing resolution at SiPM Vbias recommended by manufacturer • Timing resolution as function of SiPM Vbias ENVISION WP2 Meeting Lyon 03/02/11
SiPM characterisation ENVISION WP2 Meeting Lyon 03/02/11
Breakdown voltage Hamamatsu 3x3mm2 50mm Courtesy M Ahmed ENVISION WP2 Meeting Lyon 03/02/11
Rise time studies Laser Width: 50ps LED Width: 2ns Courtesy M Ahmed ENVISION WP2 Meeting Lyon 03/02/11
Single photon signal • Run: 80000 events • Preamp gain: 15x about 2ns ~6mV Courtesy M Ahmed ENVISION WP2 Meeting Lyon 03/02/11
Future work • Acquire faster, low-noise, higher gain preamps • Repeat and finish SiPM characterisation with new preamps • Perform timing resolution studies of single SiPMs and SiPM pairs • Select best SiPM candidate(s) ENVISION WP2 Meeting Lyon 03/02/11
Timing resolution studies ENVISION WP2 Meeting Lyon 03/02/11
Pulse Magnitude 18000 16000 14000 12000 10000 Number of Events 8000 6000 4000 2000 0 0 0.5 1 1.5 2 2.5 3 3.5 4 Magnitude (V) Timing resolution at fixed Vbias • Run: 15000 events • Hamamatsu 3x3mm2 50mm + LaBr3(Ce) crystals • Timing resolution = s • Used Vbias recommended by Hamamatsu: 71.28V and 71.31V Ch 1 = red Ch 2 = blue Courtesy M Ahmed ENVISION WP2 Meeting Lyon 03/02/11
Timing resolution – vs. – Vbias • Runs: 50000 events • Hamamatsu 3x3mm2 50mm + LaBr3(Ce) crystals • Timing resolution = s • Used narrowest windows around 22Na peak • Best timing resolution of 298ps at 71.1V = 0.18-0.21V below recommended Vbias Courtesy M Ahmed ENVISION WP2 Meeting Lyon 03/02/11
Future work • Improve two-channel demonstrator set-up: SiPM-crystal coupling, alignments, etc. • Investigate SiPM-crystal coupling • Understand effects on timing resolution of LaBr3(Ce) crystal's different geometries and Ce concentration • Continue timing resolution studies of two-channel demonstrators: different SiPM types and also LYSO crystals ENVISION WP2 Meeting Lyon 03/02/11
Summary • SiPM characterisation started: 1) breakdown voltages, 2) rise times, 3) single photon signal • Started study of timing resolution of two-channel demonstrator system: 298ps (s) • Future work: • Repeat and complete SiPM characterisation with new preamps and select best candidate(s) • Continue timing resolution studies ENVISION WP2 Meeting Lyon 03/02/11