长脉冲高能激光对金属靶材烧蚀实验研究

Ablation of metal target materials by long-pulse high energy laser

为研究长脉冲高能激光与金属靶材相互作用的机理,使用2种激光器对铝、钢、铜和钛靶材进行烧蚀试验。记录靶材穿透时的激光轰击次数,测量穿过通孔的激光能量和孔的面积,得到不同材料在不同能量密度下的烧蚀率。实验表明:能量密度低的激光束,即使对靶材可能有烧蚀作用,它的烧蚀率要比能量密度高的激光束小很多。能量密度达到造成液态质量迁移条件的长脉冲激光,可获得较大的烧蚀率和截面积较大的通孔。

The ablation experiments on different target materials such as Al, Fe, Cu and Ti were conducted by using 2 kinds of lasers to investigate the interaction of the long-pulse high-energy laser with metal target plates. The ablation ratios of various materials under different energy densities were obtained by recording the times of laser bombardment the laser took to penetrate the target material as well as measuring the laser energy going through the hole and the area of the hole. The experiments prove that the ablation ratio of the laser beam with low energy density is much lower than that of the laser beam with high energy density, even sometimes the former can still makes a limited ablation on the plate. A long-pulse laser, whose energy density can cause the liquid mass transferred, can get a greater ablation ratio and a hole with larger cross section.