1. WP2 summary of activities at Oxford Dr B Camanzi On behalf of the University of Oxford Group

2. Outline  Experimental set-up  SiPM characterisation  Timing resolution studies  Summary ENVISION WP2 Meeting Lyon 03/02/11 B Camanzi, STFC/RAL and Oxford University 2/15

3. Equipment: SiPMs and crystals ENVISION WP2 Meeting Lyon 03/02/11 B Camanzi, STFC/RAL and Oxford University 3/15

4. Experimental set-up  Two-channel demonstrator: Hamamatsu 3x3mm 2 50  m + LaBr 3 (Ce)  22 Na source  Electronics: 1.Preamps boards from Photonique: ~ 700ps rise time, gain 10x-20x 2.Keithley 2612A two-channel Sourcemeter 200V  DAQ: LeCroy WavePro 725Zi 2.5GHz oscilloscope ENVISION WP2 Meeting Lyon 03/02/11 ScopeKeithley Two-channel demonstrator system B Camanzi, STFC/RAL and Oxford University 22 Na source 4/15

5. Studies carried out so far  SiPM characterisation 1.I-V curves and breakdown voltages 2.Rise time measurements 3.Single photon signal  Timing resolution studies of a two-channel demonstrator: 1.Timing resolution at SiPM V bias recommended by manufacturer 2.Timing resolution as function of SiPM V bias ENVISION WP2 Meeting Lyon 03/02/11 B Camanzi, STFC/RAL and Oxford University 5/15

6. SiPM characterisation ENVISION WP2 Meeting Lyon 03/02/11 B Camanzi, STFC/RAL and Oxford University 6/15

7. Breakdown voltage SiPM type Breakdown Voltage (V) Recommended V bias (V) Hamamatsu 3x3mm 2 50  m Ch 169.671.28 Ch 269.671.31 Hamamatsu 3x3mm 2 25  m Ch 169.671.10 Ch 269.670.96 Hamamatsu 1x1mm 2 50  m Ch 168.269.63 Ch 268.269.63 Hamamatsu 1x1mm 2 25  m Ch 168.570.80 Ch 269.471.79 ENVISION WP2 Meeting Lyon 03/02/11 Hamamatsu 3x3mm 2 50  m Courtesy M Ahmed B Camanzi, STFC/RAL and Oxford University 7/15

8. Rise time studies Rise time (ns) Laser LED Hamamatsu 3x3mm 2 50  m 5.925.36 Hamamatsu 3x3mm 2 25  m 4.744.23 Photonique 2x2mm 2 3.683.32 ENVISION WP2 Meeting Lyon 03/02/11 Courtesy M Ahmed B Camanzi, STFC/RAL and Oxford University LED Width: 2ns Laser Width: 50ps 8/15

9. about 2ns ~ 6mV Single photon signal  Run: 80000 events  Preamp gain: 15x ENVISION WP2 Meeting Lyon 03/02/11 Courtesy M Ahmed B Camanzi, STFC/RAL and Oxford University 9/15

10. 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) B Camanzi, STFC/RAL and Oxford University ENVISION WP2 Meeting Lyon 03/02/11 10/15

11. Timing resolution studies ENVISION WP2 Meeting Lyon 03/02/11 B Camanzi, STFC/RAL and Oxford University 11/15

12. Timing resolution at fixed V bias  Run: 15000 events  Hamamatsu 3x3mm 2 50  m + LaBr 3 (Ce) crystals  Timing resolution =   Used V bias recommended by Hamamatsu: 71.28V and 71.31V ENVISION WP2 Meeting Lyon 03/02/11 00.511.522.533.54 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 Pulse Magnitude Magnitude (V) Number of Events Ch 1 = red Ch 2 = blue Cut on Ch 1Cut on Ch 2  (ns) N. of Events 2.000 - 2.4002.100 - 2.5001.15984459 2.100 - 2.3002.200 - 2.4001.01513018 2.150 - 2.2502.250 - 2.3500.76251086 2.180 - 2.2202.28 0- 2.3200.5684154 2.190- 2.2102.29 0- 2.3100.438429 2.195 - 2.2052.295 - 2.3050.41335 Courtesy M Ahmed B Camanzi, STFC/RAL and Oxford University 12/15

13. Timing resolution – vs. – V bias  Runs: 50000 events  Hamamatsu 3x3mm 2 50  m + LaBr 3 (Ce) crystals  Timing resolution =   Used narrowest windows around 22 Na peak  Best timing resolution of 298ps at 71.1V = 0.18-0.21V below recommended V bias ENVISION WP2 Meeting Lyon 03/02/11 Courtesy M Ahmed B Camanzi, STFC/RAL and Oxford University 13/15

14. Future work  Improve two-channel demonstrator set-up: SiPM-crystal coupling, alignments, etc.  Investigate SiPM-crystal coupling  Understand effects on timing resolution of LaBr 3 (Ce) crystal's different geometries and Ce concentration  Continue timing resolution studies of two- channel demonstrators: different SiPM types and also LYSO crystals B Camanzi, STFC/RAL and Oxford University ENVISION WP2 Meeting Lyon 03/02/11 14/15

15. 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 (  )  Future work: 1.Repeat and complete SiPM characterisation with new preamps and select best candidate(s) 2.Continue timing resolution studies ENVISION WP2 Meeting Lyon 03/02/11 B Camanzi, STFC/RAL and Oxford University 15/15