神光Ⅱ大型固体高功率激光装置是我国激光驱动器发展历史的里程碑, 其成功研制使我国高功率固体激光工程与技术、聚变物理与基础物理研究实现了全面且本质的跨越式发展。简要概述了神光Ⅱ激光装置研制中创新发展的大量工程方案与技术手段, 举例介绍了神光Ⅱ激光装置在近20年来的高质量运行中取得的众多有国际影响力的研究成果。经多方支持和多年持续发展, 已经形成数万焦耳级纳秒激光装置、皮秒拍瓦以及飞秒拍瓦激光装置等, 这些装置是我国惯性约束核聚变、强场物理、高能量密度物理等研究领域中重要的物理实验核心平台之一。

Through the use of time and space integrated kiloelectronvolt (keV) spectroscopy, we investigate the thermal emission of plasma, which produces strong line emission from the titanium K shell (He-\alpha at 4.7 keV and H-alpha at 4.9 keV), created by laser. In order to optimize the conversion efficiency enhancement on titanium foils, the experiment is conducted under a variety of laser-driven intensity conditions. The X-ray emission intensity at 4.7 keV is measured and compared with prediction. The experimental result demonstrates that the solid Ti target laser-produced plasma (LPP) source has X-ray emission at 4.7 keV, which are all generated from electronic transitions in Ti ions at pulse width of 2.1 ns or 30 ps, the crudely evaluated He-\alpha X-ray intensity appears to slightly increase with laser intensity enhancement, and the pre-pulse effect increases the conversion efficiency of the He-\alpha X-ray. In addition, a 90-\mum-thick Ti foil as a filter is used to transmit He-\alpha X-ray at near 4.7 keV, creating a quasi-monochromatic transmission and greatly reducing the lower- and higher-energy background.

用Si(Li)X射线能谱仪测量了低能放射性源~(55)Fe的辐射强度,用“时间标尺”法对5F型医用X光片和Kodak无屏X光片乳剂对于~(55)Fe辐射的特性曲线作了定量标定.结果表明,对于5F底片,与密度D=1相应的曝光量H_(D=1)=12×10~7photo/cm~2.

在激光等离子体实验中,用晶体谱仪可获得高温等离子体所发射的X光谱。本文介绍我们设计和使用的X光晶体谱仪的原理、结构及晶体衍射参数,谱仪的线色散率,谱线加宽和谱仪窗口等有关参数,并给出了摄谱的典型结果。