一种用于DT聚变诊断的新型中子谱仪的设计

Design of a Novel Neutron Spectrometer for DT Fusion Diagnosis

介绍了一种基于反冲质子法和磁分析技术的新型DT聚变中子谱仪,能够以高信噪比对9—17MeV的中子能谱进行精确测量,适用于稳态及脉冲条件下的等离子体温度(Ti)和燃料面密度(ρR)的诊断,对14MeV的初级DT中子具有约4%的能量分辨率和约10-8的探测效率。谱仪的磁分析系统使用高性能钕铁硼二极永磁铁建造,焦平面上使用CR-39固体径迹探测器测量反冲质子的位置分布。使用239Puα源对磁分析系统进行了实验研究,并建立了配套的粒子输运模拟程序。结合实验和程序模拟结果,使用蒙特卡罗软件模拟分析了谱仪整体性能。谱仪结构紧凑、性能良好且适用于稳态及脉冲辐射场,可望在未来的聚变研究中得到有效应用。

Design of a novel spectrometer for measurements of neutrons in the energy range 9—17 MeV has been proposed.Based on proton recoil method and magnetic analyzing technigue,the spectrometer can be used to determine DT fuel areal density（ρR）and ion temperature under steady state and pulsed radiation field.The detection efficiency is about 10^-8 for measuring 14 MeV neutrons with an energy resolution of about 4%.A neodymium-iron-boron permanent dipole was used for the magnetic analyzing system and CR-39 track detectors were used in the focal plane.The system has been tested with 239Pu α suorce and a corresponding particle transport simulation program has been worked out.Performance of the spectrometer was investigated with Monte Carlo simulation,experiment data and the transport simulation.Due to its good performance,compact structure,and availability for both steady state and pulsed radiation field,the spectrometer can be effectively used for fusion research in the future.