LHAASO-WFCTA SiPM成像探头研制进展

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草岑席
5 years ago
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1 THE PROGRESS OF SIPM-BASED CAMERA FOR LHAASO-WFCTA Baiyang Bi, Shoushan Zhang, Lingling Ma, Liqiao Yin for the LHAASO Collaboration

2 Outline Introduction LHAASO-WFCTA Why SiPM? Progress Design of Camera/Sub-Cluster Design of SiPM Pre-amplifier Analog & Digital Board Slow Control Board Winston Cone Summary 2

3 LHAASO KM2A: 5195 EDs 1171 MDs WCDA: 78,000 m cells(25m 2 /cell) WFCTA: 16 Cherenkov telescopes (1024 pixels/telescope) Mount. Haizi, Daochen, Sichuan (29 o N, 100 o E, 4410 m a.s.l., 600 g/cm) 3

4 WFCTA Prototype LHAASO-WFCTA 16x16 Pixels 32x32 Pixels 1 o /pixel 0.5 o /pixel PMT Array SiPM Array 4

5 Introduction to SiPM Silicon Photomultiplier Geiger mode APD(binary) SiPM 1~5mm Same Output APD 20~100μm NN ffffffffff = NN cccccccc 1 ee εεnn ppp NN cccccccc = NN cccccccc (1 ee NN pppp NN cccccccc ) 5

6 PMT vs SiPM PMT (WFCTA) SiPM Size 1 inch (25.4mm) 15mm x 15mm Resolution 12%@100pe, 4%@1000pe 12%@100pe, 4%@1000pe FWHM of Pulse ~6ns ~60ns Dark count rate(dark noise) Th=0.5pe Th=0.5pe Gain 10 >1000V 10 <100V G-T Stability ~0.2%/ 1.5%/ Magnetic field Sensitive Not sensitive Ageing under strong light Yes No Dynamic range Depend on PMT type, HV. Depend on number of APDs 6

7 Why SiPM? High gain at low operating voltage Duty cycle up to 30% (10% for PMT) Experience of FACT & CTA The First G-APD Cherenkov Telescope (FACT) La Palma, Canary Islands, Spain, 2011 CTA: single-mirror (dual mirror) Small Size Telescope(High Energy) 7

8 Moon trajectory 8x2 Telescopes 128 o x 32 o 90 o ±64 o,30 o ±16 o 8

9 Design of Camera Camera Box Sub-Cluster: 4x4 SiPM array Optical Filter Camera: 8x8 Sub-Clusters 9

10 Design of Sub-Cluster Winston Cone Frame Slow Control Board SiPM Array Pre-amplifier Board Analog Board Digital Board 10

11 Design of SiPM Two Terminal Strips Temperature Sensor LM94021 Test Sample: Hamamatsu S (4x4) chips 3mm x 3mm per chip Pixel Size: 25μm x 25μm Hamamatsu 9 (3x3) chips (15mm x 15mm) 5mm x 5mm per chip Pixel size: 25μm x 25μm Gain=1.1x10 Gain Uniformity: Typ:1.3% Dark Count Rate = Typ:5.4Mhz V-T Coefficient: 54mV/ 11

12 Pre-amplifier a R2 = 3Ω, R3 = 100Ω,R4 = 1kΩ V a = I x 3Ω Inverting Amplifier: Gain =

13 Pedestal Ped < 5mV σ ~ 0.43mV 13

14 Dynamic ranges NN ffffffffff = NN cccccccc 1 ee εεnn ppp NN cccccccc = NN cccccccc (1 ee NN pppp NN cccccccc ) rrrrrr 1 = NN cccccccc ln ( ) 1 NN ffffffffff NN cccccccc NN pppp Deviation < ±2% up to pe 14

15 Resolution 15

16 Stability of the Gain Keep operating voltage stable Duration of fluorescence signal could reach several μs 16

17 Design of Analog/Digital Board 15.6x Pre-amplifier 16 x 0.696x FADC 50MHz,12bit FADC 50MHz,12bit FPGA AB DB 17

18 Test of AB/DB Dynamic Range: Deviation < ±2% 10 pe ~ 32000pe Resolution: 10pe >70pe 18

Design of Slow Control Board Temperature Sensor LM94021

19 Design of Slow Control Board Temperature Sensor LM X SiPMs 16 X FADC SLC HV sensor 55V~65V FPGA 54mv/ 19

20 Trigger algorithm First level trigger:single channel trigger Signal to noise ratio: S/N>n Threshold varies with the intensity of the sky background light. Second level trigger: pattern recognition Patterns Cherenkov Event Fluorescence Event 20

21 Gain monitor The Gain of SiPM The SiPM gain (break down voltage) is sensitive to the temperature. The voltage drop on the R 0 varies with the intensity of the sky background light. Monitor the high gain and the low gain of the electronics. UV-LEDs configuration Low Temperature Coefficient (~ 0.2%) Pulse width <20 ns 21

22 Gain monitor Point Light Source Light source: 12mm Focus distance: 2870mm Camera size: 800mm 3.88% lower at corner than center 500pe (x 1,2,3,4,5,6) Vcc FPGA 50/100MHz DEIC420 x6 LED 22

23 Winston Cone Pixel:25.4mm In:24.4mm 0 8 Out:15mm Height: 25.3mm 23

24 Simulation Photons on focal plane = 2.87 Photons on SiPM surface 24

25 Summary Camera Design We have designed a new SiPM Pre-amplifier, AB,DB have been finished, more tests are undergoing Slow Control Board is being developed Winston cone is being tested Time schedule First SiPM camera will be built before Jan. 2018; 6 telescopes based on SiPM camera will be built and run before the end of telescopes will be run at

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27 DEIC420 In/Out 10ns 20ns In Out 27

28 Signal to noise ratio SiPM PMT (R7899) Relative PDE/QE nm nm Dark count threshold=0.5pe 5.4MHz <1kHz Sky background noise ~37 MHz ~21MHz S/N Ratio 0.11Ns 0.087Ns SSNN = NN ss ppp PPPPPP NN ppp pppp BBBB PPPPPP + NN DDDDDD NN ss ppp ppp NN BBBB PPPPPP 28

Concept of Hyper Kamiokande (20 times Super K) 48m x 50m x 250m x 2 Total mass ~ 1 Mton Photocathode coverage ~40% of surface ~200,000 PMTs => prohibi

Concept of Hyper Kamiokande (20 times Super K) 48m x 50m x 250m x 2 Total mass ~ 1 Mton Photocathode coverage ~40% of surface ~200,000 PMTs => prohibi R&D of a Large Format Hybrid Photo-Detector (HPD) for a Next Generation Water Cherenkov Detector Tokyo - HPK joint R&D program H.Aihara University of Tokyo HPK =Hamamatsu Photonics 1 presented at Next