气炮加载实验中光学窗口透射率测量技术及其应用

Technique for Measuring Transmittance of Optical Windows under Dynamic Loading and Its Application

报道一种用于气炮加载条件的窗口透射率测量技术。该技术将一种激发电压低(4.5 V)、响应时间快(约500 ns)、输出功率稳定的半导体脉冲光源设置在弹丸内部,在碰靶前激发出光,作为照明光源,用于观测透明样品/窗口在加载过程中的透射率变化。将该技术用于石英玻璃冲击透明性研究,发现石英玻璃在经冲击压缩再卸载到水的过程中,其透射率下降了近30%,该结果不支持文献中所给出的液态水压致固化的解释。

A measurement technique for optical transmittance of window material under gas-gun-driven shock loading condition was developed,in which a pulsed light source of semiconductor laser was mounted in the projectile and along its central axis to measure the transmittance change of transparent sample during loading and unloading processes.The advantages of the light source over the traditional xenon lamp are：（1） the work voltage is only 4.5V;（2） the response time is less than 500ns;（3） the output power is stable.The improved method provides an important tool for studying the transparency change,absorption,and failure of brittle materials.Quartz glass,as an example,is found to partially lose its transparency during the unloading process after shock compression of 1.8GPa,and the decrease of transmittance is as high as 30%.The results do not support the explanation of liquid-solid phase transition given by literature.