Measurement of the non-linearity in the gamma-ray response of the GAGG:Ce inorganic scintillator

TL;DR

This study precisely measures the non-linear gamma-ray response of GAGG:Ce scintillators across a broad energy range, crucial for optimizing space-based gamma-ray detectors.

Contribution

It provides the first accurate characterization of GAGG:Ce non-linearity in the 20-662 keV range using SDD readout, aiding detector development.

Findings

GAGG:Ce exhibits measurable non-linearity in gamma-ray response.

The measurement technique is accurate and applicable for detector calibration.

Results support GAGG:Ce's suitability for space gamma-ray detection.

Abstract

A characteristic of every inorganic scintillator crystal is its light yield, i.e., the amount of emitted scintillation photons per unit of energy deposited in the crystal. Light yield is known to be usually non-linear with energy, which impacts the spectroscopic properties of the scintillator. Cerium-doped gadolinium-aluminium-gallium garnet (GAGG:Ce) is a recently developed scintillator with several interesting properties, which make it very promising for space-based gamma-ray detectors, such as in the HERMES nanosatellite mission. In this paper we report an accurate measurement of the GAGG:Ce non-linearity in the 20-662 keV gamma-ray energy interval, using a setup composed of three samples of GAGG:Ce crystals read out by Silicon Drift Detectors (SDDs).