Arrays of digital Silicon Photomultipliers Intrinsic performance and Application to Scintillator Readout

Transcription

1 Arrays of digital Silicon Photomultipliers Intrinsic performance and Application to Scintillator Readout Carsten Degenhardt, Ben Zwaans, Thomas Frach, Rik de Gruyter Philips Digital Photon Counting NSS-MIC Conference, November 2 nd, 2010

2 How to replace old-fashioned PMTs? Take the digital SiPM 1 pixel Increase integration 2 x 2 pixel on one chip Assemble arrays 8 x 8 pixels on one PCB 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 is the key element to superior detector performance 3

4 Digital silicon photomultiplier technology The principle 4

5 Digital silicon photomultiplier technology The principle 5

6 Digital silicon photomultiplier technology The principle 6

7 Digital silicon photomultiplier technology The principle 7

8 The digital SiPM array Features 8 x 8 digital SiPMs (on 4 x 4 chips) 6400 diodes per pixel ~ 11 cm 2 4-side tiling possible Inputs 1.8 V, 3.3 V, 30 V JTAG (test and configuration) 200 MHz reference clock External trigger input Outputs 100 MHz serial data (photon count, timestamp) Event detect trigger 8

9 Measurement setup (1) dsipm array electronic trigger dsipm array Clock, Config, Data FPGA board Coincidence detection FPGA board Clock, Config, Data USB connection PC 9

10 Counts (arb. u.) Intrinsic timing performance (44 ± 1) ps FWHM Timestamp difference (ps) Timing jitter over full delay range: 44 ps FWHM 10

11 Measurement setup (2) dsipm array psec-laser dsipm array Clock, Config, Data FPGA board Coincidence detection FPGA board Clock, Config, Data USB connection PC 11

12 Counts Timing performance Timestamp difference (ps) Timing jitter over full delay range: 59 ps FWHM 12

13 Measurement setup (3) dsipm array LYSO scintillator array dsipm array Clock, Config, Data FPGA board 22 Na Coincidence detection FPGA board Clock, Config, Data USB connection PC 13

14 Scintillator readout Floodmap LYSO array, 8 x 8 crystals, 4 mm x 4 mm pitch, 22 mm length 14

15 Counts Scintillator readout Energy resolution Data: selecthist1_b Model: GaussFWHM Weighting: y No weighting % FWHM Chi^2/DoF = R^2 = y ± A ± w ± xc ± LYSO array, 8 x 8 crystals, 4 mm x 4 mm pitch, 22 mm length Energy (kev) Saturation was corrected 15

16 Pixels Scintillator readout Energy resolution LYSO array, 8 x 8 crystals, 4 mm x 4 mm pitch, 22 mm length Saturation was corrected ,5 11,0 11,5 12,0 12,5 13,0 13,5 14,0 Energy resolution (%) 16

17 Counts Scintillator readout Timing resolution 1500 LYSO array, 8 x 8 crystals, 4 mm x 4 mm pitch, 22 mm length Data: TDCsum_B Model: GaussFWHM Weighting: y No weighting ps FWHM Chi^2/DoF = R^2 = Summed timing of all 8 x 8 crystals y ± A ± w ± xc ± Timing mainly limited by photon statistics (CRT with 3x3x5 mm 3 LYSO: 153 ps) Timestamp difference (ns) 17

18 Counts Scintillator readout Timing resolution Two sources 8.3 cm apart Dt = 570 ps 8.6 cm ,5-1,0-0,5 0,0 0,5 1,0 1,5 Timestamp difference (ns) 18

19 Small crystal readout LYSO array, 30 x 30 crystals, 1 mm x 1 mm pitch, 10 mm length Log scale Data analysis by P. Düppenbecker, see talk M

20 Summary Arrays of 8 x 8 digital SiPMs operational Intrinsic timing resolution: 59 ps FWHM Performance with LYSO scintillator arrays ~12 % FWHM energy resolution 328 ps FWHM coincidence timing resolution Mainly limited by number of detected photons 20

21 Next Steps Optimize the detection (crystal coupling, anti-reflection coating, fill-factor, ) Build detector modules Work together with partners to explore further applications 21

22 Talk N58-1 (Thu, Nov 4 th, 8:00am, Ballroom G) T. Frach, The Digital Silicon Photomultiplier Prototype System Architecture and Performance Evaluation Visit us at Booth #105 22