用光学记录速度干涉仪测量自由面速度

 建立了一套光学记录速度干涉仪系统(ORVIS)，用于测量强激光产生的冲击波状态方程中的自由面速度。该光学记录速度干涉仪系统的时间分辨率为179 ps，可以测量自由面速度随时间变化的整个过程。在天光KrF高功率准分子激光装置上进行激光打靶实验，激光波长248.4 nm，脉冲宽度25 ns，最大输出能量158 J。在激光功率密度为6.24×10¹¹W·cm^-2的条件下，测得厚20 μm铁膜的自由面速度可达3.86 km/s；在激光功率密度为7.28×10¹¹W·cm^-2条件下，100 μm铝膜（靶前有100 μm的CH膜作为烧蚀层）的自由面速度可以达到2.87 km/s。

Free-surface velocity measurements using an optically recording velocity interferometer

An optically recording velocity interferometer system(ORVIS) was developed for the free-surface velocity measurements in the equation of state experiments. The time history of free-surface velocity could be recorded by the electronic streak camera. In the experiments, ORVIS got a 179 ps time resolution, and a higher time resolution could be got by minimizing the delay time. The equation of state experiments were carried out on the high power excimer laser system called “Heaven Ⅰ” with laser wavelength of 248.4 nm, pulse duation of 25 ns and maximum energy 158 J. Free-surface velocity of 20 μm thick iron got 3.86 km/s with laser intensity of 6.24×1011W·cm-2, and free-surface velocity of 100 μm thick aluminum with 100 μm CH foil at the front got 2.87 km/s with laser intersity 7.28 ×