研制了一套线面同时成像任意反射面速度干涉仪(VISAR)用于激光驱动飞片速度场时空分辨测量。将传统VISAR改为成像干涉结构,用变像管扫描相机和高速光电分幅相机分别记录作为信号载体的梳状干涉条纹,实现靶面一条线上各点速度历史和多个时刻二维靶面上所有点速度的测量。所研制的线面同时成像VISAR具有小于10 μm的空间分辨和约15 m/s的速度分辨能力,线成像VISAR时间分辨小于50 ps,面成像VISAR曝光时间小于5 ns。用其测量了激光驱动带约束刀口铝膜飞片的速度场,给出了高时空分辨全场速度分布,从中可以清晰看出飞片的演化发展过程。实验结果表明,线面同时成像VISAR将是各种飞片产生技术及相应加载手段中全场速度诊断的有力工具。
A simultaneous line imaging and plane framing imaging velocity interferometer system for any reflector (VISAR) for spatial and temporal resolution measurement of velocity field of laser driven flyer is developed. Different from the conventional point VISAR, imaging VISAR uses streak camera and framing camera to record the movement of comb fringe, and provides a one-dimensional velocity history versus time along a line and a two-dimensional velocity map of the whole surface at different time. In addition, the instrument measures velocity field at spatial resolution of 10 μm and velocity resolution of 15 m/s. The technique is employed to measure temporal and spatial velocity field of Al foils flyer driven by a pulse laser, and to reveal the continuous evolution of flyers. These results demonstrate that the simultaneous line imaging and plane framing imaging VISAR can be a valuable diagnostics for shock physics.