1. Evaluation of Silicon Photomultiplier Arrays for the GlueX Barrel Calorimeter Carl Zorn Radiation Detector & Medical Imaging Group Jefferson Laboratory, Newport News, VA 2009 NSS/MIC Symposium, Orlando, Fl Thursday, October 29, 2009 2009 NSS/MIC Symposium, Orlando, Fl Thursday, October 29, 2009 On behalf of the GlueX Collaboration www.gluex.org

2. Jefferson Laboratory www.jlab.org Under construction 2 2

3. 12 GeV upgrade – GlueX experiment Study excited gluonic meson states www.jlab.org/12GeV 3 3

4. Photodetectors in Strong Magnetic Field 2.2 Tesla SciFi●Lead Calorimeter 4 meter length 48 sectors 4 4

5. Chosen Photodetectors Silicon Photomultipliers (SiPMs) Two companies: Hamamatsu and SensL Arrays (4x4) of 3mm 2 cells Size ~ 13 x 13 mm 2 Gain > 10 6 Insensitive to B-fields Dark rate ~ 100 MHz Operation depends on temperature Hamamatsu H8409-70 1.5” PMT: R7761-70 Photocathode D = 27mm 19 stages Max. anode I = 10mA Gain ~ 3x10 6 (0.5 T) Dark rate ~ 0.5 kHz Fine Mesh PMTs (FM) SensL Hamamatsu 5 5

6. Readout Setups SiPM Option: –Inner: 6x4 SiPMs (2,304) –Outer: 2x2 FM PMTs (384)  FM PMT Option:  Inner: 3x3 FM PMTs  Outer: 2x2 FM PMTs (1,248) SiPMs: Sum in 3’s to electronics Option 1 Option 2 6 6

7. Readout Setups Full SiPM Option: –Inner: 6x4 SiPMs –Outer: 2x2x4 SiPMs (3,840) SiPMs: Sum in 3’s to electronics Option 3 7 7

8. Original Prototype Arrays Array Size: 13 x 13 mm 2 Active area: 2.85 x 2.85 x 16 mm 2 (75%) Cell: 3.15 x 3.15 mm 2 Pixel Count: 3640 x 16 (35 μm) Array Size: 16 x 18 mm 2 Active Area: 3x3x16 mm 2 (50%) Cell: 3.85 x 3.85 mm 2 Pixel Count: 3600 x 16 (50 μm) 16 mm 18 mm 13 mm SensL Hamamatsu 8 8

9. Sample Pulses 200 ns SensL Hamamatsu 9 9

10. Amplitude Distribution – SensL – Type 1 10

11. Amplitude Distribution – Hamamatsu 11

12. “Dead” channels Amplitude Distribution – SensL – Type 2 12

13. “Dead” channels Amplitude Distribution – SensL – Type 2 X 13

14. Effect of excessive bias in Hamamatsu MPPC 50 μm @ V op 50 μm @ V op + 1.0 v 14

15. Effect of Bias on Noise (SensL) Overbias = +2 v Overbias = +4 v 15

16. Temperature & Stability  Dark Rate dependent upon Overbias  Dark Rate decreases rapidly with decreasing Temperature  Dark Rate can be improved with Temperature Control  At Constant Overbias  Gain independent of Temperature Same goes for PDE  Gain varies rapidly with Overbias (1-4 volts)  Output Response strongly dependent upon Temperature  Temperature should be stable for Stable Output 16

17. PDE/Dark Rate Requirements Set by minimum detection threshold of Eγ = 60 MeV 17

18. PDE/Dark Rate Requirements Hamamatsu 50 μm Hamamatsu 25 μm 18

19. PDE/Dark Rate Requirements SensL 20 & 35 μm 19

20. PDE/Dark Rate Requirements SensL 35 μm 20

21. Performance Extrapolated to 5°C SensL 35 μm 21

22. In Summary  What We’re Getting Temperature dependent Hamamatsu SensL 22

23. BCAL Readout Modules Preamp PCB SiPM Peltier Cell Hot Plate Cold Plate Control PCB Power Connector Power Connector SMA Output Connector Preamp PCB SensL Hamamatsu 23

24. Temperature Stabilization of SiPM arrays 24

25. Option for Hamamatsu Control Gain during Temperature Variations 25

26. First Signals from Hamamatsu Unit Source – fast blue LED Ouput Risetime – 13-14 ns Output Width – 75 ns Low amplitude – 18 mV High amplitude – 2.2 V 26

27. Array Evaluation Plan  Scan all elements of arrays to verify full operation  Relative PDE measurements  Compare arrays of both vendors  Verify operation at cooled temperature (SensL)  accelerated tests to simulate long-term stability  verification of radiation tolerance (< 1 krad) For GlueX  < 2 Gy/10 yrs 27

28. In Summary  Converging to Final Detector Selection  compare final prototypes under equivalent conditions  For Hamamatsu  need temperature stabilization  gain control thru thermistor feedback as possible option  For SensL  must be cooled  this will also provide stabilization  cooling will allow for higher PDE/gain  Final selection tests to be completed by end of Jan/2010 for final technology decision (SiPM vs FineMesh PMT) 28

30. Backup Slides

31. Readout Configurations SiPM/FM Option FM PMT Option B1

32. Original Prototype Array Packages SensL Hamamatsu B2

33. SPMA-16 – Problem channels Ch. 12 Ch. 16 200 ns Gate B3

34. Scanning Setup SiPM X/Y scanner LEDs diffuser Aperture (2.5 mm  ) B4

35. Initial Alignment Setup SiPM Penta prism Sighting scope Aperture (5 mm  ) B5

36. 520 nm Emission spectrum from scintillating fiber 470 nm Kuraray SCSF-78 B6

37. Energy resolution 37 Set requirements for showers at center of Bcal module B7

38. Gain vs Temperature Ref: Lightfoot et al., J. Inst., Oct. 2008 V br as temp. decreases B8

39. Dark Rate vs Temperature Ref: Lightfoot et al., J. Inst., Oct. 2008 B9

40. New Ceramic-base SensL Array B10

41. New Ceramic-base SensL Array B11

42. Ceramic-base Hamamatsu Array B12

43. Ceramic-base Hamamatsu Array B13

44. Effect of Irradiation B14

45. Gamma Irradiation 40 Gy For GlueX => < 2 Gy/10 yrs B15

46. GlueX BCAL spec sheet B16