Solar X-ray Polarization Detector (SXPD): a solar flare detector based on GMPD

Abstract

We present the design of a solar flare detector, the Solar X-ray Polarization Detector (SXPD), based on the Gas Microchannel Plate Pixel Detector (GMPD). The primary scientific objectives are to measure the polarization state and spectrum of individual solar flares in the soft X-ray band, where polarized bremsstrahlung radiation is expected to be produced by high-energy electron beams accelerated within the solar magnetic field and plasma. The SXPD comprises two key modules: a Pinhole Imaging Tube and a GMPD module. This paper provides a detailed description of the structural design and performance of the SXPD. With its imaging capability, the SXPD can resolve individual solar flares in the soft X-ray energy range with an angular resolution of 1.5 arcsec. Based on conservative estimates, over typical durations, the detector can achieve an MDP of 15.0% - 23.0% for B-class flares, 8.0% - 12.0% for C-class flares, 2.0% - 2.3% for M-class flares, and 0.6% - 1.0% for X-class flares.