Radiation damage of MPPC by 290MeV/u C beam at HIMAC

1
Radiation damage of MPPC by 290MeV/u C beam at
HIMAC
Takayuki Tanaka Y.Itow T.Mase K.Masuda H.Menjo
T.Sako H.Watanabe Solar Terrestrial Environment
Laboratory ,Nagoya University
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
1.21010particles(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
7.5105 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)
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 V070.59V
100C_1 V069.59V 50C_2 V069.55V
100C_1 V069.48V

Beam for irradiation
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)
Set up
Circuit diagram
Optical fiber from Xenon lamp
Bias V
monitor PMTs
Xe lamp
filter
Base board of MPPCs
47kO
ion chamber
C ion beam line
9.6nF
47kO
MPPC
collimater
beam line
9.6nF
MPPC
Trigger scintillator PMT
10kO
thermometer
read out circuit

Boxes including read out circuit
Scintilation fiber PMT
Read out

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

Bias V supply
ADC CAMAC 2249W(LeCroy)
Takasago TPO120-06D

• Integrated irradiation reached at 1.21010
  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

Leak current measurement
Measure the leak current on 2 months after the
irradiation
Temperature 210.2 ?
I-V curve (2 months after)
Current (uA)
In all samples, ADC value decreased by half after
1Gy irradiation (Corresponding to 7.5105
exposure )
Around 100 Gy signal was not detected by ADC
anymore
Bias voltage(V)
Leak current of irradiated MPPCs are quite
bigger than these of not irradiated. (Tipically
10times)
Plan In this November, we will irradiate C beam
and Co gamma beam again to understand what kind
of effects occur in MPPCs.