Radiation Damage Study of SensL J-Series Silicon Photomultipliers Using 101.4 MeV Protons

TL;DR

This study investigates how 101.4 MeV proton radiation affects J-series silicon photomultipliers, revealing increased noise and dark current that impact their suitability for space applications, with minimal effect on detector gain.

Contribution

It provides the first detailed analysis of proton radiation effects on J-series SiPMs, including noise increase and detection threshold changes, relevant for space-borne scintillation detectors.

Findings

Dark current and noise increase significantly after irradiation.

Detection threshold rises to 20-40 keV post-irradiation.

Minimal impact on SiPM gain and photon detection efficiency.

Abstract

Radiation damage of J-series silicon photomultipliers (SiPMs) has been studied in the context of using these photodetectors in future space-borne scintillation detectors. Several SiPM samples were exposed to 101.4 MeV protons, with 1 MeV neutron equivalent fluence ranging from 1.27*10^8 n/cm^2 to 1.23*10^10 n/cm^2 . After the irradiation, the SiPMs experienced a large increase in the dark current and noise, which may pose problems for long-running space missions in terms of power consumption, thermal control and detection of low-energy events. Measurements performed with a CeBr3 scintillator crystal showed that after exposure to 1.23*10^10 n/cm^2 and following room-temperature annealing, the dark noise of a single 6 mm square SiPM at room temperature increased from 0.1 keV to 2 keV. Because of the large SiPM noise, the gamma-ray detection threshold increased to approximately 20 keV for a CeBr3 detector using a 4-SiPM array and 40 keV for a detector using a 16-SiPM array. Only a small effect of the proton irradiation on the average detector signal was observed, suggesting no or little change to the SiPM gain and photon detection efficiency.