Improved X-ray detection and particle identification with avalanche photodiodes

TL;DR

This paper presents a waveform fitting technique for avalanche photodiodes that enhances energy resolution, corrects timing, and enables particle identification, improving X-ray detection accuracy.

Contribution

It introduces a novel fitting method to account for detector response variations, significantly improving resolution and timing, and enabling particle discrimination in APD-based detection.

Findings

Energy resolution improved by up to a factor of 2 at 8.2 keV.

Timing accuracy improved by up to 25 ns.

Effective particle identification between X-rays and electrons.

Abstract

Avalanche photodiodes are commonly used as detectors for low energy x-rays. In this work we report on a fitting technique used to account for different detector responses resulting from photo absorption in the various APD layers. The use of this technique results in an improvement of the energy resolution at 8.2 keV by up to a factor of 2, and corrects the timing information by up to 25 ns to account for space dependent electron drift time. In addition, this waveform analysis is used for particle identification, e.g. to distinguish between x-rays and MeV electrons in our experiment.