Influence of X-ray Irradiation on the Properties of the Hamamatsu   Silicon Photomultiplier S10362-11-050C
  We have investigated the effects of X-ray irradiation to doses of 0, 200 Gy, 20 kGy, 2 MGy, and 20 MGy on the Hamamatsu silicon-photomultiplier (SiPM) S10362-11-050C. The SiPMs were irradiated without applied bias voltage. From current-voltage, capacitance/conductance-voltage, -frequency, pulse-shape, and pulse-area measurements, the SiPM characteristics below and above breakdown voltage were determined. Significant changes of some SiPM parameters are observed. Up to a dose of 20 kGy the performance of the SiPMs is hardly affected by X-ray radiation damage. For doses of 2 and 20 MGy the SiPMs operate with hardly any change in gain, but with a significant increase in dark-count rate and cross-talk probability. 
Chen Xu, Robert Klanner, Erika Garutti, Wolf-Lukas Hellweg
physics.ins-det hep-ex