Spatial resolution studies using point spread function extraction in optically read out Micromegas and GEM detectors

TL;DR

This study compares the spatial resolution of Micromegas and GEM gaseous detectors using point spread function extraction with synchrotron X-ray beams, highlighting their resolution capabilities for imaging applications.

Contribution

It introduces a method to evaluate and compare the spatial resolution of Micromegas and GEM detectors using synchrotron radiation and point spread function analysis.

Findings

Micromegas achieved a resolution of approximately 108 microns.

GEM detectors achieved a resolution of approximately 127 microns.

The method allows quantification of resolution-limiting factors in gaseous detectors.

Abstract

Optically read out gaseous detectors are used in track reconstruction and imaging applications requiring high granularity images. Among resolution-determining factors, the amplification stage plays a crucial role and optimisations of detector geometry are pursued to maximise spatial resolution. To compare MicroPattern Gaseous Detector (MPGD) technologies, focused low-energy X-ray beams at the SOLEIL synchrotron facility were used to record and extract point spread function widths with Micromegas and GEM detectors. Point spread function width of $\approx$108\,\microns for Micromegas and $\approx$127\,\microns for GEM foils were extracted. The scanning of the beam with different intensities, energies and across the detector active region can be used to quantify resolution-limiting factors and improve imaging detectors using MPGD amplification stages.