氦、氩、氪低压激光诱导等离子体激发的空间解析发射图谱的比较

Comparison in spatially-resolved emission image excited from low-pressure laser-induced plasmas using helium,argon,krypton

采用二维成像光谱仪系统,研究了铜(样品)和不同氪、氩或氦气压下激光诱导等离子体气体的发射强度空间分布。发射区的形状和强度完全取决于等离子体气体的种类和气压。这些等离子体气体的发射区基本上集中在样品表面附近,而铜样品的发射区则朝周围的气体扩展。氩或氪气压越高,铜线的发射强度越强;而对于氦等离子体,气压越大,铜线的发射强度越弱。上述效应可以通过氪、氩和氦在碰撞激发剖面图上的差别来解释。

The spatial distribution of the emission intensities of both copper （sample） and plasma gases from a laser-induced plasma was investigated by using a two-dimensionally imaging spectrometer system,when krypton, argon,or helium was employed under various pressure conditions. The shape and the intensities of the emission zone were strongly dependent on the kind and the pressure of the plasma gas. The emission zones of these plasma gases were generally concentrated near the sample surface, whereas those of the copper sample were more expanded towards the surrounding gas. The emission intensity of the copper line became enhanced at larger gas pressures of argon or krypton, while that was much less intense in the helium plasma. These effects could be explained by the difference in the cross-section of collisional excitation between krypton, argon and helium.