摘要
硅漂移探测器(silicon drift detector, SDD)是一种高性能X射线探测器,具有极其广泛的应用. SDD射线探测系统由SDD器件、前置放大器和脉冲处理系统组成,现有的SDD脉冲处理系统存在脉冲堆积抑制性能差以及易受前级系统参数波动影响的问题,导致探测系统性能变差.本文提出一种SDD数字脉冲处理系统,在该系统中,模数转换器(analog-to-digital converter, ADC)直接采样前置放大器的输出,并将数据传输到数字脉冲处理平台进行处理.结合SDD器件与前置放大器的信号特性,分析ADC采样位数与采样频率对系统性能的影响;提出两种优化的ADC采样电路,防止因ADC采样位数不足引起能量分辨率变差.对数字脉冲处理系统中的脉冲成形算法进行研究,结果表明成形信号不会因前级系统的参数变化而畸变,证明了该数字脉冲处理系统的鲁棒性.建立完成SDD数字脉冲处理系统,并对系统进行测试,验证了系统的正确性.
Silicon drift detector(SDD) is a kind of high performance X-ray detector, which is widely used. The ray detection system based on SDD is composed of SDD device, preamplifier and pulse processing system. The now available pulse processing system has the problems of poor pulse pile-up rejection performance and being vulnerable to the parameter fluctuations of front-end system, which degrades the performance of detection system. A digital pulse processing system is proposed. In this system, analog-to-digital converter(ADC) directly samples the output signal of preamplifier, and transmits the data to the digital pulse processing platform for processing. According to the signal characteristics of SDD device and preamplifier, the influence of ADC sampling bits and sampling frequency on system performance is analyzed. Two optimized ADC sampling circuits are proposed to reduce energy resolution degradation induced by insufficient ADC sampling bits. The pulse shaping algorithm in the digital pulse processing system is studied. The results show that the shaping signal will not be distorted due to the parameter fluctuations of the front-end system, which proves the robustness of the digital pulse processing system. The digital pulse processing system is implemented and tested,and the correctness of the system is verified.
作者
宋文刚
张立军
张晶
王冠鹰
Song Wen-Gang;Zhang Li-Jun;Zhang Jing;Wang Guan-Ying(Institute of Microelectronics of the Chinese Academy of Sciences,Beijing 100029,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2022年第1期74-82,共9页
Acta Physica Sinica
关键词
硅漂移探测器
数字脉冲处理
前置放大器
模数转换器
脉冲成形
silicon drift detector
digital pulse processing
preamplifier
analog-to-digital converter
pulse shaping
