超高速碰撞碎片云的四序列激光阴影照相

为研究超高速碰撞过程中所产生碎片云的特性，在中国空气动力研究与发展中心超高速所碰撞靶上发展了四序列激光阴影照相系统。该系统由YAG激光光源、阴影仪、成像系统和控制系统组成，在采用多光源空间分离、偏振分光、光束角放大、补偿式滤光等技术后，获得了撞击速度 v=4．6km／s时碎片云的四序列阴影照片。笔者对该系统的工作原理、调试情况及试验结果进行了介绍。调试及试验结果表明：（1）该系统可以获得最小间隔为1μs、曝光时间为10ns的4个不同时刻的超高速碰撞碎片云图像，满足碰撞试验中对碎片云照相的要求；（2）该技术可以发展为更多序列激光阴影照相系统，并应用于其它超高速瞬态过程的测量显示。

Four sequences laser shadowgraph for the visualization of hypervelocity impact debris cloud

Four sequences laser shadowgraph system has been set up on tne nypervelocity impact range of Hypervelocity Aerodynamics Institute, CARDC, to visualize the hyperveloeity impact debris cloud. The system includes YAG laser source, shadowgrapher and imaging system. Satisfying debris cloud image, with impact velocities up to 4.6km/s, was obtained with the technique of multi-light source divided in space, polarization decomposition, light angle magnification and compensated filter, etc.. Contents introduced in this paper are the principle, the debug of the system and the result of test. Test results show that： （1） Four images of hypervelocity impact debris cloud are gotten at different time which least interval is ls and time of exposure is 10ns, which satisfies the need of photo of the debris cloud for the research of hypervelocity impact; （2） Eight sequences laser shadowgraph system could be developed at the base of the four sequences laser shadowgraph system, and the system can be used in the field of other hypervelocity process.