基于前冲康普顿电子高能伽马能谱测量系统设计

发布时间：2019-07-23 15:30

【摘要】：除中子外,聚变核心同时释放大量高能伽马,其能谱可反映聚变过程的关键物理参数,并为过程诊断提供重要信息.由于聚变伽马的时间与能量特性,需要设计高探测效率及能量分辨率的伽马谱仪.根据高能伽马谱仪的概念设计(gamma-to-electron magnetic spectrometer),针对该系统中伽马-电子转换靶、电子偏转汇聚、电子探测等关键环节进行优化设计以提高系统探测效率及能量分辨率.其中采用Monte-Carlo程序Geant4模拟研究了伽马-电子转换靶中康普顿散射与多次库仑散射对由转换靶出射电子的能谱与角分布的影响.开发并行遗传算法对复杂几何偏转磁场参数进行优化,得到低强度(小于100 Gauss)复杂边界偏转磁场.根据系统优化设计结果,采用Geant4模拟了该系统对不同能量伽马的响应.此外,还可模拟该系统对特征聚变伽马能谱的测量,结果显示,该系统可在聚变中子产额分别为2.5×10~(15)及1.2×10~(16)条件下,对10—20 MeV高能伽马能谱测量实现能量分辨分别满足0.5 MeV(小于5%)及0.25 MeV(小于2.5%),说明该系统可用于聚变过程伽马能谱的诊断.
[Abstract]:In addition to that neutron, the fusion core release a large amount of high-energy gamma at the same time, and the energy spectrum of the fusion core can reflect the key physical parameters of the fusion process and provide important information for the process diagnosis. Because of the time and energy characteristics of fusion gamma, it is necessary to design a gamma spectrometer with high detection efficiency and energy resolution. According to the concept design of high-energy gamma-ray spectrometer, the key links such as gamma-electron conversion target, electron-deflection convergence and electronic detection in the system are optimized to improve the system's detection efficiency and energy resolution. In this paper, the influence of Compton scattering and multiple coulomb scattering on the energy spectrum and angular distribution of the emitted electrons from the target is studied by using the Monte-Carlo program, Geant4. A parallel genetic algorithm was developed to optimize the complex geometric deflection magnetic field parameters to obtain a complex boundary deflection magnetic field with a low intensity (less than 100 Gauss). According to the system optimization design results, the response of the system to different energy gamma is simulated by using the Geant4. in addition, the system can also simulate the measurement of the characteristic fusion gamma energy spectrum of the system, and the result shows that the system can be under the condition that the yield of the fusion neutrons is 2.5-10-(15) and 1.2-10-(16), The energy resolution of 10-20 MeV high-energy gamma energy spectrum was measured to satisfy the energy resolution of 0.5 MeV (less than 5%) and 0.25 MeV (less than 2.5%), and the system can be used in the diagnosis of the gamma energy spectrum of fusion process.
【作者单位】：中国工程物理研究院北京应用物理与计算数学研究所;中国工程物理研究院激光聚变研究中心;
【基金】：中国博士后科学基金(批准号:2015M581028) 国家自然基金(批准号:11675021,11505166) 中国工程物理研究院科学技术发展基金(批准号:2014A0402016)资助的课题~~
【分类号】：O571.323

【相似文献】