球面晶体背光成像系统是一种重要的惯性约束聚变诊断技术, 为了验证球面晶体背光成像系统性能, 优化成像系统结构, 利用光线追踪软件SHADOW对该系统背光成像进行模拟, 对成像系统参量中成像物体位置、球面晶体弯曲半径和布拉格角等进行了模拟分析。结果表明: 布拉格角为57°和65°的球面晶体背光成像系统, 当成像物体厚度或者物体放置的误差Δa=±1 mm,晶体弯曲半径误差ΔR=±3 mm, 布拉格角误差Δθ=±0.1 mrad时, 在子午面和弧矢面光线追踪模拟的2个成像系统的相对放大率与经过相对放大率公式计算的结果比较吻合, 说明参量的微小变化对成像系统的相对放大率影响较小, 成像系统性能稳定可靠。

X-ray imaging system based on spherically bent crystal is an important diagnostic technique for inertial confinement fusion (ICF). To testify the performance of the imaging system and optimize the structure of imaging system, the backlighting imaging system was studied by the ray tracing software SHADOW. Through the analysis for the system parametes, such as the position of object, the radius and Bragg angle, the results showed that for the spherical surface crystal back light imaging systems with Bragg angle of 57° and 65° ,when the object thickness or object laying aside error was Δa=±1 mm, the crystal bevelling radius error was ΔR=±3 mm, and the Bragg angle error Δθ=±0.1 mrad, the relative magnification of the 2 imaging systems simulated on the meridian plane and the sagittal plane through light tracing ,tailled with the computation result by relative magnification formula comparison.It is implied that the parameters have a little influence on the relative magnification of the imaging system, and the performance of imaging system is stable and reliable.