Radiation damage uniformity in a SiPM

TL;DR

This study investigates how radiation damage affects the gain and breakdown voltage of a specially designed SiPM cell exposed to neutron radiation, analyzing damage uniformity and the impact of self-heating.

Contribution

It introduces a dedicated single-cell SiPM structure for detailed radiation damage analysis and compares breakdown voltage measurements from IV and gain data.

Findings

Radiation damage affects SiPM gain and breakdown voltage.

Damage uniformity was confirmed across multiple cells.

Self-heating effects influence measurement accuracy.

Abstract

A dedicated single-cell SiPM structure is designed and measured to investigate the radiation damage effects on the gain and breakdown voltage of SiPMs exposed to a reactor neutron fluence up to $\Phi$ = 5e13 cm$^{-2}$. The cell has a pitch of 15 $\mu$m. Results of the measurements and analysis of the IV-curves are presented. Impact of the self-heating effect was investigated. The radiation damage uniformity of 1 cell and 120 cells was checked up to $U_\mathit{ov}$ = 1.7 V. Fluence dependence of the breakdown voltage from the current measurements $U^{IV}_\mathit{bd}$ was extracted and compared to that of the breakdown voltage from the gain measurements $U^{G}_\mathit{bd}$.