The position resolution of the Gas Microchannel plate Pixel Detector

The Gas Microchannel plate Pixel Detector (GMPD) is purposefully designed and manufactured for astrophysical X-ray polarization detection, slated for use in various space missions such as the Cosmic X-ray Polarization Detector (CXPD) CubeSat, Low Energy Polarimeter Detector (LPD/POLAR-2), and the Chasing All Transients Constellation Hunters (CATCH). Past research has explored the polarization and spectral performance of GMPD. This study, for the first time, experimentally investigates its imaging characteristics to validate its imaging capabilities. Utilizing a deconvolution method, we measured the position resolution of GMPD, revealing distinctions in the detector's imaging capabilities for X-rays of varying energies and in orthogonal directions. These research findings will provide targeted insights for optimizing the photoelectron track reconstruction algorithm and correcting systematic effects in polarization measurements for future applications of GMPD.