辐射驱动实验中预热对冲击波速度诊断的影响

使用主动式任意反射面速度干涉仪进行了平面靶预热膨胀量的观测,并对间接驱动下不同能量和靶型的预热膨胀量进行了计算。实验发现,在5kJ单端驱动的激光能量作用下,平面样品后界面的膨胀量可达2.1μm左右。优化靶设计后,在冲击波速度测量实验中使用双端驱动方式,通过测量膨胀量修正台阶厚度,可以获得更加精确的动态台阶厚度值。结合精确获得的冲击波传输时间,在匀速传输的条件下可以获得高精度的冲击波传输速度值。该方法在辐射驱动超高压条件下具有很好的适用性,可以为状态方程实验提供高精度的冲击波速度数据。

Effect of preheat on shock wave measure technique in laser indirect-drive experiment

In this paper, the active velocity interferometer system for any reflector has been presented to adjust the thickness change. The expansion was calculated under different laser energy and target design. The experiment shows, the expansion is about 2.1 m under 5 kJ indirect single-ended drive. The thickness change can be obtained after calculating the fringe change. After the optimization of target design in double-ended drive experiment, the step thickness can be achieved accurately with corrected preheat effect on the thickness. The time for shock wave breaking out on the step target can be achieved with the optical stream camera. Under the condition of steady velocity in step target, the shock wave velocity can be gotten from the experiment data. This technique is suitable for the shock wave experiment with radiation drive, and provided the shock wave for equation of state with high accurate.