辐射驱动冲击波速度被动式测量

在神光Ⅱ和神光Ⅲ原型装置上采用了辐射驱动冲击波速度被动式测量技术，对冲击波发光图像信噪比进行了理论分析和实验研究，结果表明：靶室内杂散光比冲击波信号至少强4个量级以上，是影响信噪比的关键因素。据此提出了信噪比控制技术，通过电磁屏蔽优化，采用了基于光触发的快时间分辨测量技术，提高了冲击波速度测量精度。基于冲击波测量辐射温度，对辐射驱动冲击波速度被动式测量技术进行了考核。实验测量的冲击波发光图像清晰，数据信噪比及冲击波速度和物理预期一致，验证了技术的可靠性。

Passive measurement of radiation driven shock velocity

The passive diagnostic for radiation driven shock velocity is of critical importance in the research of radiation driven fusion and extreme high-pressure equation of state. Such diagnostic has been set up on SG-Ⅱ and the laser prototype facility. The control technique of signal-to-noise of shock breakout images has been developed based on the theoretical analysis and experimental study which shows that the stray light such as stimulated scattering light is 4 order stronger than the shock light. The precise temporal-resolved technique has also been developed based on the successful application of the faster sweep rate of the streak camera with aids of high-quality light triggering instead of traditional electronic triggering. The developed passive diagnostic has been validated successfully by an experiment whose results show the shock image is clear and the deduced shock velocity is consistent with the calculated one.