Direct measurement technique for shock wave velocity under super high pressure

作者：Wang Feng^*; Peng Xiao-Shi; Liu Shen-Ye; Li Yong-Sheng; Jiang Xiao-Hua; Ding Yong-Kun

来源：Acta Physica Sinica, 2011, 60(2): 025202.

• shock wave
• optical diagnosis
• imaging
• interfero meter

With the ionization mechanism for the transparent material under the super high pressure, the basic measurement method of shock wave has been analyzed. With the Drude-free electron model, the change in reflectivity of shock wave front under different pressures has been analyzed. The reflectivity of shock wave front for different probe lasers has been compared in theory. And it was found that the reflectivity of shock wave front for 660 nm of probe laser is higher than that for 532 nm. The effect of the detector was found to be caused by the X-ray ionization of the transparent material after analyzing the reflectivity data in space-time scale. From the experiment data, it is found that the beginning of "blank" effect coincides with the start point of laser pulse. The shock wave is later than the "blank" effect under the square laser pulse. In the experiment, the reflectivity of shock wave front is about 40% when the shock velocity is 35 km/s. The theoretical decreasing curve of shock velocity in the sapphire window is confirmed by the experiment data. The formula to calculate the shock wave velocity in the transparent material was deduced and verified.

• 出版日期2011-2
• 单位北京应用物理与计算数学研究所; 中国工程物理研究院; 中国工程物理研究院激光聚变研究中心