Lepton Flavor Physics with Most Intense DC Muon Beam Yusuke Uchiyama

Transcription

1 Lepton Flavor Physics with Most Intense DC Muon Beam Yusuke Uchiyama

2 What we did Development and optimization of single counter Carried out 1 st pie5 with two counters <35 ps by two-counter measurement But with smaller size counter Detail study of SiPM What we have done since then Continue SiPM study Carried out 2 nd Frascati Layout study with MC

3 BC422 6x3x0.5 cm 3 3M mirror film SiPM Saint-Gobain BC422 ( mm 3 ) Achieved excellent resolution of 43 ps( ) at relatively high over-voltage Observed deterioration at further over-voltage Increase of dark noise, after pulsing

4 3 SiPM in series connection Waveform digitizer Thermal chamber Shaping amplifier Scintillator:BC422, 60x30x5mm 3 Sensor:3x3mm 2, 50μm-pixel SiPMs Reference counter:bc422, 5x5x5mm 3, 1 MPPC for trigger & collimation 90 Sr β-source (<2.28MeV) Amplification & shaping (pole-zero cancellation) High speed sampling with waveform digitizer USB PC DRS Input (4ch)

5 Further study to understand the timing resolution of plastic scintillation counter from SiPM properties Detail comparison of different type of SiPMs Recently, many manufacturers produce blue-sensitive SiPMs with p-on-n structure New MPPCs from Hamamatsu New standard MPPC New trench MPPC T.Nagano et.al, IEEE NSS/MIC 2012 HPK has recently developed new technologies After pulse suppression Trench for cross-talk suppression Metal quench resistor High fill factor for small pixel Etc. IEEE NSS/MIC 2012, VCI 2013 Id:180

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7 Manufacturer Model number Type HPK S C Conventional MPPC (Old) S P Ceramic package Surface mount S C(X) S C(X) S C(X) 3X3MM50UMLCT-B New MPPC (Standard) Trench-type MPPC 25μm pixel Improved fill factor AdvanSiD NUV type KETEK PM3350 prototype A Trench type SensL MicroFB SMT B-series with fast MicroFB SMT output 35μm pixel Common features: 3 3 mm 2 dimension, p-on-n structure

8 @23 Trench MPPC New MPPC 50μm 25μm 8 V 4 V Old MPPC 2 V Much wider operational range. Breakdown voltages are lower by 5 V (standard), 15V (trench)

9 Old MPPC (S C) 20 ns After shaping New MPPC (S C(X)) Trench MPPC (S C(X)) Average waveform Confirmed less after-pulsing

10 Dark measurement Random trigger Photo-electron counting capability Large improvement in the separation Over-voltage ~2.0 V 0pe 1pe 2pe Charge (10 9 e) Over-voltage ~2.5 V アフターパルスにより連続的な分布に Old MPPC New MPPC

11 @23 SensL New Old AdvanSiD KETEK Old MPPCs New MPPCs Kept controlled up to high V over due to the after-pulse suppression

12 @23 Standard SiPMs Trench SiPMs Cross-talk Probability # 2pe # 1pe

13 Standard NEW MPPC 1pe 2pe 5pe V over =1.5V Cross talk increases at high bias Very long tail in charge distribution Cross-talk process runaway Big impact on energy measurement (excess noise factor) Impact on time measurement? arxiv: pe 2pe 10pe V over =4.0V 100pe Saturation of electronics Charge (10 9 e)

14 (Photo Detection Efficiency) New50um 25um Trench Old SensL AdvanSiD KETEK Measure relative PDE using UV-LED (~ scinti. Light) Calculate PDE from 0 p.e. probability LED (~390nm) Extended PDE at higher V over for new MPPCs Recovered fill factor for smaller pixel (25um) Trench-type MPPC also shows good PDE due to relatively high fill factor (55%, ~10% lower than standard type) Scintillator spectrum

15 Old New50um 25um SensL Trench AdvanSiD KETEK Measure relative PDE using UV-LED (~ scinti. Light) Calculate PDE from 0 p.e. probability LED (~365nm) Extended PDE at higher V over for new MPPCs Recovered fill factor for smaller pixel (25um) Trench-type MPPC also shows lower PDE for short wavelength (?) Scintillator spectrum

16 New50um 25umTrench New50um 25um Old SensL Old SensL AdvanSiD KETEK Trench AdvanSiDKETEK LED (~390nm) LED (~365nm) *Relative scales for the two plots are not same HPK MPPCs show higher PDE for near-uv Extended PDE at higher V over for new MPPCs Recovered fill factor for smaller pixel (25um) Trench-type MPPC also shows good PDE due to relatively high fill factor (55%, ~10% lower than standard type). But PDE is suppressed at shorter wave length (?)

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18 BC422 6x3x0.5 cm 3 No wrapping Trench Old New New (25μm) Almost same resolution attained at each optimal bias. (No major improvement) Trench-type shows slightly poorer resolution

19 Trench New New (25μm) Old Observe softening of waveform as V over for standard new MPPC Slower pulse shape for Trench MPPC This sample is not the final version. HPK is trying to improve this

20 t Counter t ref Old New New (25μm) Faster charge collection by higher E-field Trench!? Pulse time by Constant-Fraction method As a consequence of softened pulse shape, time measurement drifts for applied bias Larger temperature dependence of time measurement Old New New 25um Trench 2.5 ps/ 5.5 ps/ 2.8 ps/ 0.1 ps/

21 30 C 20 C 40 C Old MPPC (S C) New MPPC (S C(X)) 20 C 25 C 30 C Temp. dependence of time(mean) at fixed bias Due to the time drift at high bias, new MPPC has higher dependence(~30ps by 5 ) Bias voltage (V) (Over C) 30 30/ 12 = 31.2 ps Detector resolution(final) Contribution from temp. (uniform distribution) Bias voltage (V) (Over C) Not an issue

22 SensL HPK MPPC attained 30 C 25 C 20 C 20 C 25 C 30 C Stable! Bias voltage (V) (Over C) ps poorer resolution Good stability for wide bias range No more care for temperature Bias voltage (V) (Over C) Breakdown coefficient AdvanSiD: 24 mv/ KETEK: 16 mv/ MPPC Old: 49 mv/ MPPC New:59 mv/

23 Tested SensL B-series Fast -output, connected in parallel Normal readout Fast output Fast output shaped by amp This could be a good solution, if our final electronics doesn t have shaper. However, Pulse-shape is not so sharp when 3 SiPMs are connected in parallel The best resolution is given when combing fast-output & our amp shaping 55 ps Huge dark noise (>x10) Operation current is as large as 80mA Need twice cable Separate line for bias

24 New MPPC After-pulse reduction, wider operation range Improvement in stability after one pulse, effective for measurement at high rate Trench-type: in addition, cross-talk suppression Comparable PDE for smaller pixel thanks to improvement in fill factor Temperature dep. of time measurement Degraded in new MPPC, but not an issue Trench-type shows high stability as KETEK, AdvanSiD Time resolution for scintillator p.e. statistics dominant PDE is the most important High resolution with HPK MPPC having high PDE at NUV Not a big improvement with the new MPPC

25 After pulse, noise Cross talk PDE Bias, Temp. stability Time resolution Old MPPC New MPPC (Standard) New MPPC (25um) New Trench MPPC AdvanSiD NUV KETEK SensL Good

26 For final optimization of single counter Test another scint. (BC422Q) Finalize counter dimension Decide SiPM in ~40 days AdvanSiD will provide modified version of NUV-SiPM Order final SiPMs in this year by Italian budget Electronics Test PCB, cable Test with final electronics (prototype of WaveDREAM) Calibration Develop calibration algorithm with Michel e + Study calibration method with laser system Construction Design mechanical structure Publication for the R&D

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28 Fast scintillators from Saint-Gobain properties BC418 BC420 BC422 BC404 Light Output [% Anthracene] Rise Time [ns] Decay Time [ns] Wavelength [nm] Attenuation Length [cm] Used in the beam test Used in this study (Best ) Present MEG timing counter Faster scintillator gives higher time resolution P.e. at the earliest part are only effective Scintillation with fast response given in near-uv light

29 One readout for 3 SiPMs connected in series Effectively large area sensor to get larger number of photons Apply x3 bias Automatic adjustment of overvoltage for each SiPM by the common current Reduction of capacitance Sharper pulse shape Decrease of gain (~40%) Over-voltage ~3.8 V /MPPC

30 New Standard, 4V New Trench, 4V New Trench, 9V Trench 型で大幅な波形のなまりを観測

31 40 C Old MPPC (S C) 25 C New MPPC (S C(X)) 30 C 30 C 20 C 20 C Bias voltage (V) (Over C) Bias voltage (V) (Over C) バイアス一定の場合の分解能の温度依存性 レファレンスカウンタは各温度で Over-voltage をそろえてある 新型では高バイアスをかけることで 到達分解能は安定に得られる

32 40 C Old MPPC (S C) 25 C New MPPC (S C(X)) 30 C 20 C 20 C 30 C Over voltage 一定での分解能温度依存性 新型 ( 旧型 )60mV/ C(55mV/ C) の温度係数を仮定して補正

33 30 C 40 C 20 C Old MPPC (S C) New MPPC (S C(X)) 25 C 20 C 30 C Bias voltage (Over C) (V) Bias voltage (Over C) (V) Over voltage 一定での時間測定温度依存性 新型 ( 旧型 )60mV/ C(55mV/ C) の温度係数を仮定して補正 もし温度変化をバイアスコントロールでアクティブに補正できれば影響を最小限にできる

34 Old MPPC (S C) New MPPC (S C(X)) 降伏電圧の温度依存性 Old:49 mv/ New:59 mv/ 参考 : AdvanSiD センサー :24 mv/ KETEK センサー :16 mv/ ( どちらも p-on-n, blue sensitive type)

35 MPPC bias voltage Input attenuater 150 MPPC Amp Amp Pole-zero cancellation Output

36 Pole-zero cancellation potentiometer 0 Ω (attenuated by 2) 200 Ω For precise time measurement Restore baseline by pole-zero cancellation, and Extract fast risepart 1000 Ω t rise ~1.7 ns Signal from scintillator (3MPPC in series connection) 0 (nsec)

37 Old V over =2.4V P crosstalk =60% New V over =2.5V P crosstalk =50% New V over =4.2V P crosstalk =70% Trench V over =8V P crosstalk =35%