New Method for Silicon Sensor Charge Calibration Using Compton Scattering

TL;DR

This paper introduces a novel calibration method for silicon sensors using Compton scattering, enabling accurate charge calibration at low thresholds crucial for next-generation radiation-damaged detectors.

Contribution

The paper adapts the Compton scattering calibration technique, previously used for scintillators, specifically for silicon sensors with thin geometries and RD53A readout chips.

Findings

Successful calibration of silicon sensors using Compton scattering

Applicable to sensors with thresholds below 1000 electrons

Demonstrates potential for improved detector calibration accuracy

Abstract

In order to cope with increasing lifetime radiation damage expected at collider experiments, silicon sensors are becoming increasingly thin. To achieve adequate detection efficiency, the next generation of detectors may have to operate with thresholds below 1000 electron-hole pairs. The readout chips attached to these sensors should be calibrated to some known external charge, but there is a lack of traditional sources in this charge regime. We present a new method for absolute charge calibration based on Compton scattering. In the past, this method has been used for calibration of scintillators, but to our knowledge never for silicon detectors. Here it has been studied using a 150 micron thick planar silicon sensor on an RD53A readout integrated circuit.