Beta-ray test for strip scintillator readout MPPC

GLD Cal group meeting @ KEK06/2/28 (Tue)

Niigata universitySayaka IBA

Contents

1. Motivation2. Best type of scintillator surface covering3. Readout MPPC4. Setup of beta-ray test5. Results

1. Signal2. Discussion of number of photon from fiber

6. Compare with readout PMT7. Summary8. Future plan

1. Motivation Scintillator Study

Compare of many type of surface covering

Select 10x40x2mm and 3M film

MPPC study Measurement of performances

Beta-ray bench test (scinti + WLS fiber + MPPC)

Example of future Calorimeter design

Scintilltor : 10x40x2mmReadout : MPPC

Can MPPC really receive few photon from scintillator?? Compare to number of photon from strip scintillator readout MAPMT

studied by Jacosalem-san

20 mm 40 mm 80 mm 120 mm 160 mm0

102030405060708090

100110120130140150

Sensor's Length

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2. Best type of scintillator surface covering

From Jacosalem-san study 3M radiant mirror film has the greatest pulse height Using 40mm length, we can catch enough signal

3M Radiant Mirror FilmTeflonBlack tape

3M radiant mirror filmTeflonAl evaporationWhite paint + teflonWhite paintBlack tapeAu evaporation

40mm 80mm 120mm

Select 3M film surface covering and 40mm length for beta-ray test

Select !

3. Readout MPPC First type from HPK,100pixels Gain : 1.41x107 Deviation of PH (RMS) : 10% Efficiency (average of 50pixels) :

~59% at 49.0V Efficiency (laser light all covered;

include cross talk) : ~75% at 49.0V. ~80% at 49.1V MPPC overview

MPPC 100pixels (10x10pixels)First type

~85um

~100um

Efficiency : 1pixel, Bias : 49.0V≧

4. Setup of beta-ray test

We connected scintillator and MPPC through wavelength sifter fiber and tried beta ray test

Measurement conditions Scintillator : 10x40x2mm strip type (surface : 3M mirror sheet) MPPC : first MPPC (100pixels), Bias 49.1V Source : 90Sr (beta-ray) WLS fiber : Φ1.0mm, length 20cm, Y-11 (Kuraray) Trigger : scintillator + PMT

Setup

5. Results

MPPC readout timing is same level as PMT timing No right leak

Signal from oscilloscope(up) from MPPC, (down) from PMT

Pedestal(using clock)

Signal

ADC graph

250ns

2mV(MPPC)

MPPC

Trigger PMT

Results cont… number of photoelectron

Pulse height = arithmetical mean （算術平均） - pedestal mean = 66.1 (ADCcount)

Number of detection photoelectron from MPPC = 6.1pe

pedestal

1pixel event

2pixel

Number of photoelectron = Pulse height (ADCcount)

10.8 (ADCcount/1pe)

# of Event

ADCcount

MPPC can detect MIP signal

Results cont… number of photon from fiber

Light spread loss from fiber PDE

PMT readout

MPPC readout

QE

Checked number of photon from fiber Both readout (MPPC and PMT) type use same condition scintillator and fiberSo, number of photon from fiber must be same

Efficiency is different between MPPC and PMTWe can’t discuss the merits to compare only number of photoelectron or pixel

We considered,,, Efficiency for MPPC readout

Particle detection effect (PDE; ε) Light spread loss from fiber

Efficiency for PMT readout Only quantum efficiency (QE)

Results cont… We considered to PDE and light

spread loss from fiber The optical resin is coated on

detection surface of MPPC Light spread from fiber and

MPPC has light loss 43% loss for 1.0mm diameter

fiber

tot

photonstotfired N

NNN

exp1

PDE (ε) = εgeom×QE×εguiger = 50%×80% (at 49.1V) = ~40%

Light spread loss from fiber

Nphotons = 15.8 (photons)

Consider to light loss -> Number of photon from fiber = ~28(photons)

Number of photon for MPPC detection : Nphotons

( # of fired pixel : Nfired = 6.1, #of total pixel Ntot = 100 )

We measured beta-ray signal from scintillator PMT readout to compare MPPC readout Measured by Jacosalem-san

Measurement conditions Readout PMT : 16ch MAPMT (H6568-10, HV: -950V, QE: ~20%) Same as conditions of readout MPPC

Scintillator : 10x40x2mm, surface covering 3M film Beta-ray source : 90Sr WLS fiber : diameter 1.0mm,

length 20cm from PMT

6. Compare of scinti - PMT result

PMT result cont… -- number of pe and photon

Number of photoelectron from PMT = 5.8 pe Number of pe = number of photon from fiber x QE of PMT (20%)

number of photon from fiber = 29(photons)

Single photoelectron peak (using PMT)Scintillator : 10x40x2mm 3M film

1pe = 13.8 ADCcount

pedestal

signal

Pulse height

Example of light yield

Number of photoelectron = Pulse height (ADCcount)13.8 (ADCcount/1pe)

7. Summary of beta-ray test We can see beta-ray signal from scintillator readout MPPC Compare detection (number of pixels or photoelectron) and num

ber of photons from fiber

Light detection ability of MPPC is good as PMT for MIP The way of calculation for light loss from fiber spread is almo

st good

We can say that “signal of 1pixel = signal of 1photonelectron”

Device Fiber dia (mm) # of detection photonelectron

# of photon from fiber

MPPC 1.0mm 6.1±0.7 (pixels) 28±10 (photons)PMT 1.0mm 5.8±0.5 (pe) 29±6 (photons)

8. Future plan at Niigata

Check to number of photon from laser using PMT Use photon counting PMT (R6353P, R6358-10: side on type) Laser light inject PMT directly Search 1photonelectron peak

Check 1pixel event is certainly from 1photon 1photon laser light inject MPPC

UG students are studying SiPM from Russia and MPPC 400pixels (first type)