Electronics system for the cosmic X-ray polarization detector

This study presents an electronics system for cosmic X-ray polarization detection(CXPD). The CXPD was designed as a high-sensitivity soft X-ray polarimeter with a measurement energy range of 2–10 keV carried by a CubeSat. A stable and functionally complete electronics system under power and space constraints is a key challenge. The complete CXPD electronics system(CXPDES) comprises hardware and firmware. CXPDES adopts a three-layer electronic board structure based on functionality and available space. Two gas pixel detectors(GPDs) were placed on the top layer board, and CXPDES provided the GPDs with voltages up to-4000 V. Each GPD signal was digitized, compressed, encoded, and stored before being transmitted to the ground. The CXPDES provided stable and high-speed communication based on a scheme that separated command and data transmission, and it supports the CXPDES in-orbit upgrade. In addition, environmental monitors, silicon photomultiplier(SiPM) triggers, power management, GPDs configuration, and mode switches were included in the overall operating logic of the CXPDES. The results obtained by testing the CXPDES showed that it satisfied all the requirements of CXPD. The CXPDES provides design experience and technological readiness for future large-area X-ray polarimetry missions.