新式气体切伦科夫探测器光学系统设计及效率分析

Optical System Design and Efficiency Analysis of Novel Gas Cherenkov Detectors

气体切伦科夫探测器是惯性约束聚变的重要诊断设备,可用于聚变反应历程的测量。基于探测器的测量原理,并针对传统卡塞格林光学系统的不足,分析了一种新型气体切伦科夫探测器的光学结构,采用3片90°离轴抛物镜和1片平面反射镜组成的离轴光学系统,将探测窗口置于光学系统的出瞳位置,可减小同轴系统的缺陷提高光收集效率;利用多次反射镜反射增加光程,实现干扰信号分离。分析了光学系统的光束限制和光线追迹结果,比较了离轴系统与传统同轴系统的光收集效率。结果表明,离轴光学系统的光学效率为8.3%,同轴光学系统的效率为0.5%。

Gas Cherenkov detectors （GCDs）, based on converting fusion gamma into photons, is an important diag- nostic tool for archiving fusion reaction history measurements. A novel design of the GCD using three pieces of 90° off-axis parabolic mirror and a turning flat mirror, will take the place of the conventional GCD using Cassegrain reflector optics. Light collection is more effective by using the off-axis optical system and positioning the optical detector at the exit pupil of the optical system. Optical ray tracing demonstrates that how light can be collected by the optical detector from different object surface. A comparison analysis of the novel and traditional system given in the paper shows that light collection efficiency is 8.3% by using the off-axis system while the efficiency is 0.5% by using Cassegrain reflector optics.