应用于天基探测粒子分辨的四阈值过阈时间-波形甄别（QuadTOT-PSD）方法研究

In space-based detection, high fluence rate background radiation constituted by high energy heavy charged particle, electron, γ-ray and other cosmic ray will seriously interfere the detecting of low fluence rate and energy rays such as soft X-ray. It’s necessary for data acquisition system (DAQ) to identify desired signals under this condition in order to reduce the interference. Limited by the size of the detector, high energy particles will generate interfere signals which are similar to the desire signals when just deposit partial energy.Thus, it is hard to identify the desired particle through traditional amplitude discriminating methods with over-threshold comparator. The pulsed shape discrimination method named ‘Full waveform sampling + Digital signal process’ which is widely used in ground-based detection can identify different particles according to the differentiations of signal waves. However, it can not be used in space-based detection efficiently as the trouble of spacecraft payload, power consumption, and aerospace-grade standard. This project plans to develop a QuadTOT-PSD method to solve the problem in the soft X-ray space-based detection through the research on the sorts, energy range and intensity of the background radiation and the major structure of the soft X-ray detectors. The characteristic of pulsed signals can be identified by only several samples of the whole wave. Then a small-scale signal discriminating circuit with low power consumption, high-speed response and dead time free can be developed to meet the special requirement in space-based detection.

在天基辐射探测中，高能重带电粒子、电子、γ射线等注量率较高的本底辐射会对软x射线等低能、低注量率射线的测量造成严重干扰，这需要数据获取系统(DAQ)能在该条件下对指定粒子的信号波形进行甄别，剔除本底辐射的干扰。由于探测器尺寸有限，高能粒子仅沉积部分能量时将会产生和被测信号幅度相近的干扰信号，因而传统的基于过阈比较器的幅度甄别方法难以进行粒子分辨。地面探测常用的“全波形采样+数字信号处理”波形甄别方法，虽然可以根据信号波形的差别进行粒子分辨，但由于航天器载荷、功耗以及器件标准等方面的限制无法有效的应用在天基探测中。本项目针对天基软x射线探测的应用背景，通过对本底辐射的种类、能量范围和强度的调研和分析，结合主流的软x射线探测结构，开展QuadTOT-PSD的方法研究，通过对信号波形的有限抽样，完成其特征的识别，实现一种规模小、功耗低、响应快、无死时间的信号波形甄别方案，满足天基探测的特殊需求。

本项目针对天基软x射线探测的应用背景，通过对本底辐射的种类、能量范围和强度的调研和分析，结合主流的软x射线探测结构，开展QuadTOT-PSD的方法研究，通过对信号波形的有限抽样，完成其特征的识别，实现一种规模小、功耗低、响应快、无死时间的信号波形甄别方案，满足天基探测的特殊需求。项目立项初期对系统的技术指标要求已全部达成：时间刻度250ps，能量刻度100eV，信噪比50dB。项目顺利的按照预期计划完成了QuadTOT-PSD四阈值波形甄别系统的开发，并支持合作研究单位顺利推进x射线脉冲星导航任务。