# Radiation Hardness tests with neutron flux on different Silicon photomultiplier devices

## TL;DR

This study evaluates the radiation hardness of various Silicon Photomultiplier devices by exposing them to neutron fluxes similar to those in high-energy physics experiments, analyzing changes in key electrical parameters.

## Contribution

It provides the first systematic assessment of neutron-induced effects on different SiPM models used in particle physics experiments.

## Key findings

- Neutron flux causes significant changes in SiPM dark current and gain.
- Different SiPM models exhibit varying levels of radiation tolerance.
- Results inform selection of radiation-hard SiPMs for high-radiation environments.

## Abstract

Radiation hardness is an important requirement for solid state readout devices operating in high radiation environments common in particle physics experiments. The MEGII experiment, at PSI, Switzerland, investigates the forbidden decay $\mu^+ \to \mathrm{e}^+ \gamma$. Exploiting the most intense muon beam of the world. A significant flux of non-thermal neutrons (kinetic energy $E_k\geq 0.5 ~MeV$) is present in the experimental hall produced along the beamline and in the hall itself. We present the effects of neutron fluxes comparable to the MEGII expected doses on several Silicon PhotoMulitpliers (SiPMs). The tested models are: AdvanSiD ASD-NUV3S-P50 (used in MEGII experiment), AdvanSiD ASD-NUV3S-P40, AdvanSiD ASD-RGB3S-P40, Hamamatsu and Excelitas C30742-33-050-X. The neutron source is the thermal Sub-critical Multiplication complex (SM1) moderated with water, located at the University of Pavia (Italy). We report the change of SiPMs most important electric parameters: dark current, dark pulse frequency, gain, direct bias resistance, as a function of the integrated neutron fluency.