惯性约束聚变的中子半影成像诊断系统的优化研究

在激光驱动的惯性约束聚变实验中，中子半影成像是重要的诊断方法.基于分辨率的要求，模拟了中子源与半影孔装置间不同距离、半影孔装置不同厚度、半影孔装置不同外径以及不同孔型的系统点扩展函数，通过分析点扩展函数的尖锐性和等晕性优化诊断系统.同时还给出了系统的装配误差要求，并发现系统在线性重建时能达到15 μm分辨率，而非线性重建时能满足5 μm分辨率的诊断要求. 关键词： 中子半影成像 Monte Carlo方法 系统优化 分辨率

Optimization of diagnostic system for neutron penumbral imaging in inertial confinement fusion

Penumbral imaging of the neutron production in laser-driven inertial confinement fusion experiment is an important diagnostic technique. In order to meet the resolution requirement, we simulate the point spread function (PSF) under the conditions of different source-aperture distances, different thicknesses, different outer radii, and different shapes of the aperture. Base on the sharpness and the isoplanaticity of PSF, the diagnostic system can be optimized. According to the simulation results, tolerant misalignment of system is analysed: a resolution of 15 μm can be satisfied by the linear reconstruction method, and a resolution of 5 μm can be achieved by using the nonlinear reconstruction method.