针对惯性约束聚变实验中X射线辐射源精确诊断的需求，开展了针孔成像系统在编码成像应用中的研究。研究目的是建立符合实际实验几何条件的物理模型，分析有限尺寸光源与针孔孔径对点扩散函数以及成像分辨的影响，为后续编码孔径设计与反演算法优化提供理论基础。在该研究中，构建了基于几何光学光线追踪的数值模拟模型，模拟光源至针孔及探测器平面的传播过程；通过统计大量光线的空间分布得到系统的PSF，并进一步与目标光源进行卷积运算，得到真实探测器平面的光强分布；同时对成像结果进行反演分析，评估成像系统的空间响应特性。主要结果表明，在当前尺度条件下系统PSF主要受光源尺寸以及几何放大倍率控制，小孔对能量通量和边缘形态产生调制作用，但对中心结构影响有限。反演结果验证了模型的物理合理性，为ICF编码成像系统参数优化和图像重建提供了可靠理论支撑。
To meet the demand for precise diagnostics of X-ray radiation sources in Inertial Confinement Fusion (ICF) experiments, research on the application of pinhole imaging systems in coded imaging was conducted. The objective of this study is to establish a physical model consistent with actual experimental geometric conditions, and to analyze the effects of extended sources and pinhole apertures on the point spread function (PSF) and imaging resolution. This provides a theoretical basis for subsequent coded aperture design and inversion algorithm optimization. In this study, a numerical simulation model based on geometrical ray-tracing was constructed to simulate the propagation process from the source through the pinhole to the detector plane. By statistically analyzing the spatial distribution of a massive number of rays, the system's PSF was obtained, which was then convolved with the target source to yield the actual intensity distribution on the detector plane. Simultaneously, an inversion analysis of the imaging results was performed to evaluate the spatial response characteristics of the imaging system. The main results indicate that, under the current scale conditions, the system's PSF is primarily dominated by the source size and geometric magnification. The pinhole aperture modulates the energy flux and edge morphology, but has a limited effect on the central structure. The inversion results verify the physical validity of the model, providing reliable theoretical support for parameter optimization and image reconstruction in ICF coded imaging systems.

 

高能量X射线成像；小孔成像；编码成像；数值模拟；