Radiation damage of MPPC by 290MeV/u C beam at HIMACRadiation damage of MPPC by 290MeV/u C beam at HIMACTakayuki Tanaka Takayuki Tanaka Y.Itow T.Mase K.Masuda H.Menjo T.Sako H.Watanabe

Solar Terrestrial Environment Laboratory ,Nagoya University

Beam for irradiation

Accelerator HIMAC (Chiba,Japan)

Beam particle

Carbon 6+ ion

Energy 290MeV/nucleon

Beam intensity

10-107(particle/mm2 ∙s) = 0.05Gy/h-50kGy/h (for MPPCs)

Two types of MPPC were irradiated

Type 1: HPK S10362-11-050C (400 Pixel)

Type 2: HPK S10362-11-100C (100 Pixel)

Two samples for each type were tested

Type 1 Type 2

50C_1 Ｖ０＝ 70.59V 100C_1 Ｖ０＝ 69.59V

50C_2 Ｖ０＝ 69.55V 100C_1 Ｖ０＝ 69.48V

C ion beam line

Optical fiber from Xenon lamp

thermometer

Boxes including read out circuit

Base board of MPPCs

Set upSet up

In all samples, ADC value decreased by half after 1Gy irradiation

(Corresponding to 7.5*105 exposure )

Leak current measurementLeak current measurement

Cur

rent

(uA

)

Measure the leak current on 2 months after the irradiationTemperature ： 21±0.2 ℃

I-V curve (2 months after)

Leak current of irradiated MPPCs are quite bigger than these of not irradiated. (Tipically 10times)

Irradiation!

MethodMethod50C_1 50C_2

Bias72.0V Bias72.0V100C_1 100C_2

Bias70.0V Bias70.0V

Around 100 Gy signal was not detected by ADC anymore…

ADCCAMAC 2249W(LeCroy)

0

1

2

3

4

5

6

7

8

9

10

68 68.5 69 69.5 70 70.5 71 71.5 72

50C_1

50C_2

100C_1

100C_2

50C notirradiated

not１００Ｃirradiated

•Beam intensity is monitored by ion chamber,scintillator and scintilation fiber.(use as the beam intensity region)

PlanIn this November, we will irradiate C beam and Co gamma beam again to understand what kind of effects occur in MPPCs.

Bias V supply

collimater

ion chamber

Trigger scintillator + PMT

Scintilation fiber + PMT

MPPCbeam

line

Xe lampmonitor PM

Ts filter

read out

circuit

Abstract: We present the damage of MPPC by 290 MeV/u C6+ ion beam by HIMAC accelerator. We irradiated C6+ beam, which intensity was changed from 10 to 107(particle/s).Finally 1.2*1010particles(corresponding 16kGy) are irradiated to MPPCs.At the same light input, the output from MPPCs decreased by half after 1Gy irradiation.(1Gy irradiation corresponding to 7.5*105 C6+ exposure). And we also measured leak current 70 days after the irradiation. This current value was also higher than that of same type of MPPC(not irradiated)

Bias V

47kΩ

47kΩ

9.6nF

9.6nF

10kΩ

Read out

MPPC

Circuit diagram

Takasago TPO120-06D

Bias voltage(V)

•Integrated irradiation reached at 1.2*1010 particles (corresponding to 16kGy)

•Measure the MPPCs output charge at each dose by illuminating with a Xenon lamp. Several tens of photons reach to each MPPC per pulse.

•Charge was measured by ADC and average ADC value was evaluated every after exposure