The digital Silicon Photomultiplier A novel Sensor for the Detection of Scintillation Light

Transcription

1 The digital Silicon Photomultiplier A novel Sensor for the Detection of Scintillation Light Carsten Degenhardt, Gordian Prescher, Thomas Frach, Andreas Thon, Rik de Gruyter, Anja Schmitz, Rob Ballizany Philips Digital Photon Counting NSS-MIC Conference, October 27 th, 2009

2 Imagine you want to detect weak light signals Photomultiplier Tubes Avalanche Photodiodes Silicon Photomultipliers (SiPM) 2

3 Digital Photon Counting The Concept Intrinsically, the SiPM is a digital device (a single cell breaks down or not) analog SiPM digital SiPM (dsipm) TDC and photon counter Digital Cells Summing all cell outputs leads to an analog output signal and limited performance Digital output of Number of photons Time-stamp Integrated readout electronics are the key element to superior detector performance 3

4 Digital silicon photomultiplier technology The principle

5 Digital silicon photomultiplier technology The principle

6 Digital silicon photomultiplier technology The principle

7 Digital silicon photomultiplier technology The principle Talk N28-5 Booth 213

8 Measurement setup dsipm LYSO scintillator dsipm Clock, Config., Data 22 Na Clock, Config., Data FPGA board Coincidence detection FPGA board USB connection PC

9 Measurement setup FPGA board Two teflon wrapped crystals in coincidence 22 Na source USB connection to PC Clock distribution 9

10 Coincidence Timing (ps) Coincidence Timing Resolution 4 x 4 mm 2 LYSO crystals on 3.8 x 3.3 mm 2 active area ( ~22% of scintillation photons lost) Crystal length: 22 mm 15 mm 5 mm st 2nd Trigger setting (photons) Experiment taken at room temperature No temperature stabilization 10

11 Counts (arb. u.) Coincidence Timing Resolution 3 x 3 x 5 mm 3 LYSO crystals on 3.8 x 3.3 mm 2 active area Energy window: FWTM of 511 kev peak 153 ± 6 ps FWHM Coincidence Timing (ps) Experiment taken at room temperature No temperature stabilization Data: Smoothed Model: gaus_fw Weighting: y No weig Chi^2/DoF = R^2 = y A w xc

12 Counts Energy Resolution 4 x 4 x 22 mm 3 LYSO crystal on 3.8 x 3.3 mm 2 active area % FWHM Gamma energy (kev) Saturatíon was corrected Experiment taken at room temperature No temperature stabilization 12

13 Saturation Correction p N ln 1 k N N: active cells (7800) k: triggered cells p: # of photons Experiments taken at room temperature No temperature stabilization 13

14 Photopeak shift (%) Temperature Dependence dsipm 0.6 %/ C Temperature dependent light output of LYSO: 0.2 %/ C (2) 0.45 %/ C (3) MPPC 8.2 %/ C (1) Temperature ( C) 1 K. Burr et al, Nuclear Science Symposium Conference Record, N18-2, R. Mao et al, IEEE Transactions of Nuclear Science, vol. 55, C. Kim, Nuclear Science Symposium Conference Record, M07-113,

15 Summary Digital SiPM operational Integrated electronics at cell level Integrated time-to-digital converter and photon counter Fully digital interface Main benefits of the dsipm Best possible timing due to first photon trigger No additional ASICs needed Low sensitivity to temperature variations Low power consumption Easy system integration 15

16 Next Steps Optimize the detection (anti-reflection coating, fill-factor, crystal coupling) Operate larger detector arrays Work together with partners to explore further applications 16

17 Talk N28-5 (Wed, Oct 28 th, 2:30pm, Grand Ballroom 7) T. Frach, The Digital Silicon Photomultiplier - Principle of Operation and Intrinsic Detector Performance Visit us at Booth 213