Self-heating Effect in Silicon-Photomultipliers

TL;DR

This paper investigates the self-heating effects in silicon photomultipliers (SiPMs) caused by radiation damage, providing methods to measure and correct for temperature-induced performance changes, especially in damaged devices.

Contribution

It introduces a measurement approach for assessing self-heating in SiPMs and offers correction techniques for radiation-damaged devices' parameters.

Findings

Self-heating significantly affects SiPM performance post-radiation damage.

A method to measure steady-state temperature as a function of power and thermal resistance.

Preliminary results demonstrate the feasibility of the proposed correction approach.

Abstract

The main effect of radiation damage in a Silicon-Photolumtiplier (SiPM) is a dramatic increase in the dark current. The power dissipated, if not properly cooled, heats the SiPM, whose performance parameters depend on temperature. Heating studies were performed with a KETEK SiPM, glued on an Al$_2$O$_3$ substrate, which is either directly connected to the temperature-controlled chuck of a probe station, or through layers of material with well-known thermal resistance. The SiPM is illuminated by a LED operated in DC-mode. The SiPM current is measured and used to determine the steady-state temperature as a function of power dissipated in the multiplication region of the SiPM and thermal resistance, as well as the time dependencies for heating and cooling. This information can be used to correct the parameters determined for radiation-damaged SiPM for the effects of self-heating. The method can also be employed for packaged SiPMs with unknown thermal contact to a heat sink. The results presented in this paper are preliminary.