A brief overview of the studies on the irreversible breakdown of LGAD testing samples irradiated at the critical LHC-HL fluences

Abstract

LGAD sensors will be employed in the CMS MTD and ATLAS HGTD upgrades to mitigate the high levels of pile-up expected in the High Luminosity phase of the LHC. Over the last several years, much attention has been focused on designing radiation tolerant gain implants to ensure that these sensors survive the expected fluences, (more than 1–2 × 1015 neq/cm2). However, in test beams with protons and a fs-laser, highly irradiated LGADs operated at a high voltage, have been seen to exhibit violent burn-out events that render the sensors inoperable. This paper will focus on the critical electric field and accordingly the bias thresholds to mitigate the risk of Single Event Burnout (SEB).