在惯性约束聚变研究中获得滞止阶段内爆靶丸芯部状态图像具有极其重要的意义和价值。高功率密度拍瓦装置打击高Z金属靶产生轫致X射线(>70 keV)光源，并利用康普顿背光照相获取该图像是重要的诊断方法。基于神光Ⅲ主机装置48×3 kJ的驱动能力开展相关背光照相性能研究。结合国外相关实验结果和数值模拟计算方法分别从光源亮度以及内爆过程产生的噪声分析入手，从理论上设计了整套康普顿成像系统。结果表明在神光Ⅲ主机上利用康普顿背光照相可以获得高质量的内爆压缩靶丸滞止阶段图像。

Pivotal parameters and restricted condition of the grating-size-limited compressor in an ultra-short, ultra-intense laser system are analyzed, and three basic parameters are obtained. An optimal method for compressor to output a maximal pulse energy is developed, and the maximal output pulse energy of the grating-size-limited compressor is given. Compared with the traditional circular beam method, an advanced elliptical beam method is presented, which could be used to output much higher pulse energy, a smaller spot size and a larger focal intensity. Using numerical simulation, the maximal output pulse energy of the 500 mm grating compressor based on the circular beam and the elliptical beam are calculated separately. The results show that the 500 fs, 500 J, 1 PW pulse can be obtained without using tiled grating technology if elliptical beam method is used.

分析了超短超强激光系统中有限尺寸光栅压缩器设计的关键物理参数及约束条件,得到了压缩器优化的三项基本变量。给出了一种输出能量最大化的压缩器优化方法,进而确定了有限尺寸光栅压缩器的最大工作能力。针对传统的圆光束方案提出了改进的椭圆光束方案,增大了聚焦能量,减小了焦斑尺寸,提高了峰值聚焦功率密度。通过数值模拟对500 mm曝光口径介质膜光栅在圆光束和椭圆光束两种方案下的最大输出能力进行分析比较,指出单块光栅在椭圆光束方案下可以实现500 fs,500 J,1 PW的脉冲输出。