板间距对空间约束激光诱导铝等离子体光谱特性的影响

Effect of plate spacing on spectral properties of laser-induced Al plasma with spatially confinement

开展了平板空间约束条件下板间距对纳秒激光诱导铝等离子体发射光谱特性的影响研究,获得板间距对等离子体光谱增强因子和光谱增强时间的影响规律,以及板间距对等离子体电子温度和电子密度的时间演化影响规律。研究结果表明,在平板空间约束下,由于反弹冲击波压缩等离子体羽的作用,使等离子体光谱出现了增强,在板间距为8 mm、10 mm和12 mm平板空间约束下,激光诱导铝等离子体光谱的最大光谱增强因子分别为2.3、1.7和1.3倍,对应的时间延时分别为8μs、11μs和12μs。在平板空间约束下,激光诱导铝等离子体电子温度和电子密度均有提高。随着平板间距增大,电子温度和电子密度增大出现的时间越延后,与空间约束等离子体发射光谱强度的时间演化规律一致。

In this paper, the effect of plate spacing on the characteristics of nanosecond laser-induced aluminum plasma emission spectroscopy under the flat-plate spatial confinement was studied. The laws of the influence of plate spacing on the plasma spectral enhancement factor, spectral enhancement time and the time evolutions of plasma electron temperature and electron density were obtained. The research results shown that the plasma spectrum was enhanced due to the bouncing shock wave compression interaction with the plasma plume under the spatial confinement, and the maximum spectral enhancement factors of the laser-induced aluminum plasma spectrum were 2.3, 1.7 and 1.3 times with the plate spacing of 8 mm, 10 mm and 12 mm, respectively, corresponding to the time delays of 8 μs, 11 μs and 12 μs. The electron temperature and electron density of the laser-induced aluminum plasma were increased with spatial confinemen. With the increasing of the plate spacing, the delay time of enhancement of electron temperature and electron density appeared more delaye, which was consistent with the time evolution of the spatially confined plasma emission spectral intensity.