新型针孔点背光发光模型与实验研究

纳秒级强激光(～1014 W/cm2)与固体靶相互作用可以获得高亮度的Multi-keV能段X射线.在当前的高能量密度物理研究中利用这样的X射线背光源照相方式可以获得高质量的物理图像,具有重要的应用价值.以模拟计算与神光Ⅱ激光装置实验结果相结合的方式研究了激光等离子体发光模型.在该模型的基础上改进了针孔点背光成像技术,独立发展了针对低Z靶材料K线的准单能背向针孔点背光和针对中Z靶材料L带的高亮度侧向针孔点背光.在神光Ⅱ激光装置上通过新型针孔点背光对惯性约束聚变靶丸样品成像获得了高质量的静态靶丸流线图像,空间分辨优于10μm.实验结果表明新型的针孔点背光具备高亮度,高空间分辨,高图像衬度等优点可以广泛应用于高能量密度物理和惯性约束聚变的研究中.

Radiation model and experimental research on novel pinhole-assisted point-projection backlight

High flux, Multi-keV X-rays, can be efficiently produced from nano-second laser interaction with metal target. Multi-keV backlight X-ray source is very important in inertial confinement fusion and high-energy density physics research. The one-dimensional numerical simulation results propose a laser plasmas radiation model, and the model is compared well with Shenguang II experimental results. The pinhole-assisted point-projection (PAPP) backlight is improved by the model; the rear-on PAPP backlight for low-Z metal target and the side-on PAPP backlight for middle-Z metal target are developed. The experiment is performed on Shenguang II 9th laser facility. The static stream line obtained with novel PAPP backlight provides high-quality capsule image, and the spatial resolution is better than 10 μm. Results show that novel PAPP backlight has advantages of traditional PAPP in source brightness, spatial resolution and image contrast.