R&D status of 13inch HAPD

1. R&D status of 13inch HAPD T. Abe, H. Aihara, M. Iwasaki, T. Uchida (Univ. of Tokyo) M. Tanaka, (KEK) Y. Kawai, H. Kyushima, M. Suyama (HPK) M. Shiozawa (ICRR)

2. Introduction • We believe HAPD is an useful photon detector for 2km detector in T2K. • We have developed large (13-inch) HAPD. • In this talk, we present the R&D status of the HAPD.

3. HAPD HAPD uses avalanche diode as e multiplier. # of parts < 1/10 of PMT

4. 190ps σ Theme • Excellent HAPD performance than PMT’s • Single photon sensitivity • Single photon time resolution ~ 190ps (s) • Readout system development dedicated for HAPD • Possible application to other field

5. Bombardment: x4500@20kV Ne/sNe=67 Avalanche Gain: X30 Total Gain:~105 Principle of HAPD Operation HAPD PMT 1st Dynode Gain: x5 Ne/sNe=2.2 Incident Light Incident Light Photoelectron Photoelectron Large gain @ 1st mult. stage  good single photon detection 10~20kV Dynodes Avalanche Diode No Dynodes (No TTS)  large HAPD with good time resolution Total Gain:~107 Total Gain:~105

6. Property of HAPD • Single photon sensitivity large gain at the first stage of multiplication • Good time resolution No TTS in dynodes • Cost reduction and easy Quality control simple structure without dynodes • Lower gain Need a dedicated readout system

7. t f HAPD system (Q, T) QP.H. TTime ≥1Gsps MOF 13-inch HAPD Pre-amplifier ASIC (Low noise) Waveform sampling (Fast sampling) +Digital filter (Noise Suppression) HAPD performances are evaluated using this system

8. 13inch HAPD performances • Energy measurement related items • Comparison between HAPD and PMT • Dynamic range • Position dependence of relative gain • Timing measurement related items • Comparison & # of P.E. dependence • HV dependence

9. HAPD and PMT 1P.E. 2P.E. 3P.E. 4P.E. 1P.E. 5P.E. 2P.E.(?) HPD（HV=12ｋV bias=330V) PMT(13inch)

10. :Sample A :Sample B :Sample C Dynamic range (no preamplifier) 3000p.e. equivalent input 110 HV=+20kV, Bias=290V for Sample A 370V for Sample B 390V for Sample C Light Source: Pulsed Laser (PW: ~70ps, λ: ~400nm) 100 90 80 Output/input [%] 70 60 -3% Deviation at Output Charge of 100pC (~3000p.e. input signal intensity equivalent at total gain of ~2x105) 50 40 1 10 100 1000 Output Charge [pC]

11. 18cm ~65deg. Position dependence of gain for photons<5 Gain uniformity:s~2%

12. 45 deg 70 deg Time resolution (large HAPD) Time resolution = Transit time variation Timing resolution Center

13. Timing resolution Spot Laser illuminated HV=12ｋV bias=330V Better st No dependence of # of p.e. 190ps

14. Photoelectron transit time Center Bias=290V Light Source: Pulsed Laser (PW: ~70ps, λ: ~400nm) 45 deg 70 deg Position dep. of Transit time < 1 nsec

15. HAPD vs. PMT

16. Under development f FPGA 1Gsps AMC t Pre-amplifier ASIC Analog memory cell (AMC) + FPGA for Digital Filter f HAPD electronics status (Q, T) ≥1Gsps MOF

17. HAPD electronics status • Preamplifier (low noise) We achieve intrinsic ENC to be 3400 leading S/N~60 for the HAPD gain of 2X105. • Analog Memory Cell (fast sampling) AMC + slow FADC is cheaper than fast FADC. Sampling speed of 1GHz and signal depth of 512ns are obtained. • FPGA We start to develop a dedicated FPGA board for DSP.

18. Application for 2km detector • The 13inch HAPD might be very big for 2km detector. • We will develop HAPD to apply for 2km detector in the following way • Small HAPD (8inch) will be fabricated in the next fiscal year. • Multi-pixel HAPD (13inch) can obtain fine segmentation without increasing # of HAPD (low cost).

19. Summary • We develop a 13inch HAPD and confirm • Excellent single photon st~190ps. • Excellent single photon sE~44%. • Total gain of > 2X105. • We develop a dedicated readout electronics for the HAPD.