摘要
在惯性约束聚变(Inertial Confinement Fusion,ICF)实验中,为诊断等离子体区域温度信息,需要通过中子飞行时间法测量中子的能谱,即转化为对探测器的输出信号相对于激光同步脉冲的延迟时间进行精确测量。本文介绍了一种对中子飞行时间进行高精度测量的设计方案,该方案采用恒比定时方法(Constant Fraction Discriminator,CFD)对探测器输出信号进行定时,并利用德国ACAM公司生产的TDC-GP21芯片进行精确时间测量。基于该方案完成的测量电路电子学分辨时间在1 500 ns量程内均优于200 ps。同时,其电子学分辨时间加上探测器分辨时间典型测量结果为217.5 ps。
Background： In inertial confinement fusion （ICF） experiments, the temperature and density of fusion plasma zone are extremely important parameters requiring to diagnose. Purpose： The aim is to design a circuit for diagnosing the temperature information of the plasma zone. Methods： In order to diagnose the temperature information of plasma zone, neutron time-of-flight method was adopted to measure the neutron energy spectrum, i.e., to measure the delay time between the signal of the detector and start signal. We designed a program to accurately measure the time-of-flight with constant fraction discrimination （CFD） method, and used the TDC-GP21 （Time Digital Conversion） produced by ACAM Company （Germany） to complete accurate time measurement. Results： Based on the program, the electronics time-resolution of the measurement circuit within 1 500 ns range is higher than 200 ps, and the measurement deviation is smaller than 0.06%. At the same time, the typical result of electronics time-resolution included detector time-resolution is 217.5 ps. Conclusion： The recording capability and measurement accuracy of the circuit designed can meet the needs of practical applications, which could be used in neutron diagnosing.
出处
《核技术》
CAS
CSCD
北大核心
2015年第7期49-54,共6页
Nuclear Techniques
基金
国家自然科学基金(No.11475121
No.11205108)资助
