Analysis of radiation damage in silicon charge-coupled devices used for dark matter searches

TL;DR

This paper presents a novel method to identify and analyze radiation-induced crystal defects in CCDs caused by nuclear recoils, enhancing dark matter detection capabilities.

Contribution

It introduces a new technique to detect individual nuclear recoil defects in CCDs, aiding in distinguishing dark matter signals from background noise.

Findings

First study of individual nuclear recoil defects in CCDs.

Demonstrated defect detection via leakage current increases.

Potential to improve dark matter search sensitivity.

Abstract

Nuclear recoils in crystal detectors generate radiation damage in the form of crystal defects that can be measured in scientific-grade CCDs as local hot spots of leakage current stimulated by temperature increases in the devices. In this proceeding, we use a neutron source to generate defects in DAMIC-M CCDs, and using increases in leakage current at different temperatures, we demonstrate a procedure for identifying crystal defects in the CCDs of the DAMIC-M experiment. This is the first time that individual defects generated from nuclear recoils have been studied. This technique could be used to distinguish nuclear recoils from electron recoils in some energy ranges, which would improve the ability of CCD detectors to search for weakly interacting dark matter.