A method is proposed for compressing laser pulses by fast-extending plasma gratings (FEPGs), which are created by ionizing a hypersonic wave generated by stimulated Brillouin scattering in a background gas. Ionized by a short laser pulse, the phonon forms a light-velocity FEPG to fully reflect a resonant pump laser. As the reflecting surface moves with the velocity of light, the reflected pulse is temporally overlapped and compressed. One- and two-dimensional fully kinetic particle-in-cell simulations with a laser wavelength of 1 µm show that in this regime, a pump pulse is compressed from 10–40 ps to 7–10 fs (i.e., a few optical cycles), with a two-dimensional transfer efficiency up to 60%. This method is a promising way to produce critical laser powers while avoiding several significant problems that arise in plasma-based compressors, including an unwanted linear stage, major plasma instabilities, and the need for seed preparation.

为实现惯性约束聚变（ICF）内爆燃烧停滞阶段过程中最大压缩时刻的冷燃料面密度分布测量，设计了包含字母客体与针孔阵列的照相客体，通过同一发相同视角测量源分布与客体照相技术，首次建立了皮秒激光驱动的高能X射线源编码照相技术。通过星光III实验研究，基于W丝阵靶照相的反演图像空间分辨率5.4 μm±0.7 μm；激光到X射线（50～200 keV）的能量转换效率，W丝阵靶5.4×10⁻⁴，与传统Au单丝靶的转换效率（4.8×10⁻⁴）一致。基于源编码照相解决了传统皮秒激光背光照相中空间分辨率与光源亮度不能兼顾的困难，为强背景干扰下提供高信噪比、高分辨率的ICF靶丸压缩背光图像提供了重要照相方式。

提出了一种基于混合像素探测器作为记录介质的用于激光聚变内爆D³He质子源能谱和产额测量的在线磁谱仪诊断系统。通过对探测器上特征团簇数目和能量的识别，结合诊断系统排布，可以快速获取激光聚变反应产生的D³He质子源的能谱和产额。在神光装置上对该诊断系统进行了测试。实验使用31束纳秒激光聚焦到靶丸上驱动聚变反应。靶丸内充有原子比1∶1的D₂和³He的混合气体。在线磁谱仪诊断系统测量到了中心能量在14.6 MeV、半高全宽为2.1 MeV、产额约(2.3±0.13)×10⁹的初级D³He质子能谱。该系统的建立可以实时给出D³He质子源能谱和产额信息，从而更加及时地指导实验的开展。

The results of a commissioning experiment on the SILEX-Ⅱ laser facility (formerly known as CAEP-PW) are reported. SILEX-Ⅱ is a complete optical parametric chirped-pulse amplification laser facility. The peak power reached about 1 PW in a 30 fs pulse duration during the experiment. The laser contrast was better than 10¹⁰ at 20 ps ahead of the main pulse. In the basic laser foil target interaction, a set of experimental data were collected, including spatially resolved x-ray emission, the image of the coherent transition radiation, the harmonic spectra in the direction of reflection, the energy spectra and beam profile of accelerated protons, hot-electron spectra, and transmitted laser energy fraction and spatial distribution. The experimental results show that the laser intensity reached 5 × 10²⁰ W/cm² within a 5.8 µm focus (FWHM). Significant laser transmission did not occur when the thickness of the CH foil was equal to or greater than 50 nm. The maximum energy of the accelerated protons in the target normal direction was roughly unchanged when the target thickness varied between 50 nm and 15 µm. The maximum proton energy via the target normal sheath field acceleration mechanism was about 21 MeV. We expect the on-target laser intensity to reach 10²² W/cm² in the near future, after optimization of the laser focus and upgrade of the laser power to 3 PW.

基于超短超强激光的短脉冲中子源是实现超快中子探测的理想中子源。如何提升中子产额是目前短脉冲激光中子源实现应用需求亟需解决的关键问题。提出基于靶背鞘场加速机制和束靶反应方案，采用LiD复合组分靶作为中子转换体，可以有效提升激光中子产额。与常规的LiF转换体相比，除了p-Li和d-Li两个反应道之外，LiD转换体可以多出p-D和d-D两个反应道，因此可充分利用激光加速的质子和氘离子的多反应通道优势来提升中子产生概率。实验结果表明，相比于LiF转换体，LiD转换体可带来中子产额2～3倍的提升，达到5.2×10⁸ n/sr的最高中子产额，并具备更好的前冲性。实验还区分了多反应通道的贡献，证明中子产额提升主要来自于p-D反应。