冲击波作用下CHBr_3/NaCl界面热弛豫特性研究

STUDY OF THERMAL RELAXATION AT CHBr_3/NaCl INTERFACE UNDER SHOCK COMPRESSION

非透明材料冲击温度测量是通过对界面光辐射历史的观察实现的 ,因此对界面光辐射历史的研究是非透明材料冲击温度测量的基础。但由于冲击阻抗的失配导致界面上出现波的反射而引起温度的变化与界面热流动产生的温度变化交杂在一起 ,以及过程的瞬时性 ,使得对这一过程的实验研究显得非常困难。设计了一种界面波阻抗近似相同的特殊实验装置 ,用光辐射测量技术研究了在冲击压缩下CHBr3/NaCl界面的热弛豫过程。实验结果和理论分析表明CHBr3/NaCl界面的热弛豫时间在纳秒量级 ,与Grover等人的理论预估一致。

Shock temperature measurement of opaque materials is through measuring the optical radiation at sample/window interface.So the research of optical radiation history at sample/window is fundament of shock temperature measurement of opaque materials.But this research is not easily realized because of the mixture of temperature changing at the interface caused by thermal diffusion and wave reflecting because of mismatching of shock impedance between sample and window material.In this paper a special experiment system was proposed for researching the thermal relaxation process.The experimental results at two shock pressure points show that the thermal relaxation time is about nano second,which agrees with the theoretical result calculated by Grover et al.