针对超高压下透明材料的高压离化机理,分析了透明材料中冲击波直接诊断技术的基本方法.利用Drude自由电子气模型,分析了不同冲击压力下冲击波阵面反射率的变化.设计了专门的实验,将探测器致盲区与信号区错开,获得了蓝宝石中冲击波阵面反射的信号.结果表明:冲击波速度为32 km/s时,其波阵面的反射率约为35%,致盲效应出现时间与激光脉冲峰值到达时刻相同,持续时间也与激光脉宽相同.分析了致盲应产生的原因,并提出了解决办法.给出了加蓝宝石窗口后的测速公式,经过和实验对比,确认了测速公式的正确性.%According to the ionization mechanism of transparent material under super high pressure, the direct diagnosis method of shock wave has been analyzed. With the Drude free electron model, the reflectivity difference of shock wave front under different pressures was analyzed. The blank effect in the detector was studied, which is caused by the X-ray ionization of transparent material, after analyzing the reflectivity data in space-time scale. The experiment shows that the beginning point and duration of blank effect are consistent with the start point and duration of laser pulse, respectively. And the reflectivity of shock wave front is about 35％ when the shock velocity is 32 km/s. The reason and solution for blank effect was presented. The formula to calculate the shock wave velocity in transparent material was also deduced and verified.
展开▼
