Studies on the time response distribution of Insigh}-HXMT/LE

TL;DR

This paper investigates the time response distribution of the LE instrument on China's Insight satellite by designing a long exposure readout mode to measure photon readout times, providing a probability distribution of these times.

Contribution

It introduces a novel long exposure readout mode to accurately measure the photon readout time distribution of the CCD236 detector on Insight/ HXMT/LE.

Findings

Successfully measured the photon readout time distribution.

Provided a probability distribution model for photon readout times.

Enhanced understanding of the detector's temporal response characteristics.

Abstract

The Hard X-ray Modulation Telescope (HXMT) named Insight is China's first X-ray astronomical satellite. The Low Energy X-ray Telescope (LE) is one of its main payloads onboard. The detectors of LE adopt swept charge device CCD236 with L-shaped transfer electrodes. Charges in detection area are read out continuously along specific paths, which leads to a time response distribution of photons readout time. We designed a long exposure readout mode to measure the time response distribution. In this mode, CCD236 firstly performs exposure without readout, then all charges generated in preceding exposure phase are read out completely. Through analysis of the photons readout time in this mode, we obtained the probability distribution of photons readout time.