1. R&D of MPPC in kyoto
M.taguchi

2. picture
I will show you real one later!

3. MPPC(Multi pixel photon coutner)
MPPC characters:
100~1000 APD pixel in 1mm2
Each pixel operates as Geiger mode
　(independent of input light)
The output is a sum of all the APD signals
Compact
Low-cost
Insensitive to the magnetic field
Low bias voltage :30~75V
High gain:105~107

4. Raw signal and ADC hist of MPPC2 1
Great performance for photon counting

5. History of R&D 2005.Apr~ measurement of fundamental performance
feedback to HPK
2005.Nov
2005.Dec laser test of the sample we used at beamtest
2006.Jan we got the new samples
2006.Feb feedback to HPK
2006.Mar~ laser test of the new samples
2006.May feeback to HPK
Now at this stage

6. Summary of the parameter of the new sample
type
# of pixel
gain
Cross talk
PDE(MPPC)/QE(PMT)
HPK32
400
6.55×105
0.11
2.1
HPK53
100
2.64×106
0.21
@noise rate=800kHz,T=20℃

7. Uniformity in 1pixel gain efficiency RMS/mean=2% HPK53(100pixel)
bias=68.8V
1pixel
gain
laser
100μm
RMS/mean=2%

8. Uniformity of each pixel
efficiency
Uniformity of each pixel
HPK53(100pixel)
Bias=68.8V
RMS/mean=3%
gain
Total 100pixel
RMS/mean=3%

9. N-Grid P0D FGD ECAL SMRD Elec. Noise (TH) 10~40kHz Gain 1E5~1E6
Linearity
~10PE
>200
~100
#Pixels
>100
>1000
>500
Target (MIP) 10 20 15
Dynamic Range
<2000
Timing Resolution
~10ns
~2ns
2.5ns
Sensor diameter
1mm
1.2mm
1.1mm
Package Size
<10mm
<5mm
PDE
>15%
Threshold (TH)
>1.5
>1.5(2.5)
>0.5
For 16ch
7fc
Noise (TH)
10~40kHz

10. Summary and future plan
The new samples satisfy T2K requirement
We can use MPPC in T2K (particularly in On-Axis)
Study Individualtiy of large number of samples
Readout electronics
Packaging
Beamtest of S type scintillator with MPPC

11. Back up

12. Measurement of gain MPPC gain Q = e・(amp gain) amp
Blue LED
Measurement of gain
Charge sensitive ADC
amp
X10～100
MPPC
電荷量
# event
0p.e
1p.e
Caluculate charge of 1p.e
MPPC gain Q = Q
e・(amp gain)
素電荷

13. Measurement of gain 311-53-1A-002-1 311-32-1A-002-5 3×106 1×106 15℃
20℃
20℃
1×106
25℃
25℃
68.4
69.6
68.4
69.4
Bias V
Bias V

14. Crosstalk measurement
Crosstalk‥ photons emitted from one pixel during the Geiger discharge 　　　　　　　　causes the Geiger discharge at neighboring pixels
・Assuming 2p.e noise is caused by crosstalk of 1p.e noise(accidental coincidence of 1p.e noise is negligible)
Data taken by random trigger
Crosstalk rate =
1.5p.e
0.5p.e

15. Measurement of crosstalk
15℃
15℃
15℃
0.3
0.3
20℃
20℃
20℃
25℃
25℃
25℃
68.4
69.6
68.4
69.4
Bias V
Bias V

16. Beamtest @KEK in Nov.2005 setup Motivation (more than 5p.e for MIP)
0.5～1.4GeV/c
proton & pion
～100 event/spill
beam size 1x1cm2
Motivation
・Can the light yield for T2K near detector be obtained?
beam
64ch MAPMT
(as reference)
(more than 5p.e for MIP)
HPK100e or Russian SiPM
4 layers
Scintillator 1.3x2.5x50 cm3
　(used in K2K scibar detector)
1mmΦ fiber

17. Beamtest@KEK(cont’d)
MPPC type
MPPC p.e for MIP
PMT p.e for MIP
Ratio of MPPC p.e with PMT(%)
HPK100#13
9.9
18.3 54
HPK100#14
10.2
18.2 56
HPK100#16
13.3 73
Russian600#13
22.9
126
Russian600#14
17.1 94
・The measured PDE including optical contact for HPK100 and Russian SiPM are about 0.7 and 1.0 of PMT, so obtained light yield is consistent with the expectation considering the misalignment of a fiber

18. Uniformity in 1pixel gain crosstalk efficiency RMS/mean=1.7%
HPK32(400pixel)
bias=68.8V
gain
crosstalk
0.25
RMS/mean=1.6%

19. Uniformity of each pixel
efficiency
Uniformity of each pixel
HPK32(400pixel)
Bias =68.8V
RMS/mean=3.4%
crosstalk
gain
0.18
RMS/mean=2.9%
RMS/mean=16%

20. KL→π0νν