The performance of IHEP-NDL LGAD sensors after neutron irradiation

TL;DR

This study evaluates the impact of neutron irradiation on LGAD sensors used in high-energy physics, showing significant degradation in charge collection and timing resolution at high fluences.

Contribution

It provides empirical data on LGAD sensor performance degradation after neutron irradiation up to 2.5 x 10^15 neq/cm2.

Findings

Collected charge drops from 40 fC to 7 fC at highest fluence

Timing resolution worsens from 29 ps to 39 ps after irradiation

Signal-to-noise ratio decreases from 48 to 12 at high fluence

Abstract

The performances of Low Gain Avalanche diode (LGAD) sensors from a neutron irradiation campaign with fluences of 0.8 x 10^15, 15 x 10^15 and 2.5 x 10^15 neq/cm2 are reported in this article. These LGAD sensors are developed by the Institute of High Energy Physics, Chinese Academy of Sciences and the Novel Device Laboratory for the High Granularity Timing Detector of the High Luminosity Large Hadron Collider. The timing resolution and collected charge of the LGAD sensors were measured with electrons from a beta source. After irradiation with a fluence of 2.5 x 10^15 neq/cm2, the collected charge decreases from 40 fC to 7 fC, the signal-to-noise ratio deteriorates from 48 to 12, and the timing resolution increases from 29 ps to 39 ps.