激光诱导Al等离子体中电子密度和温度的实验研究  

Experimental Investigation on the Electron Density and Electron Temperatureof Laser-Induced Al Plasmas

作　　者：唐晓闩[1] 李春燕[1] 朱光来[1] 季学韩[1] 凤尔银[1] 张为俊[2] 崔执凤[1] 

机构地区：[1]安徽师范大学物理系原子与分子物理实验室,安徽芜湖241000 [2]中国科学院安徽光学精密机械研究所环境光谱学实验室,安徽合肥230031

出　　处：《中国激光》2004年第6期687-692,共6页Chinese Journal of Lasers

基　　金：安徽省原子与分子物理重点学科建设经费;安徽省教育厅重点项目 (2 0 0 1KJ116ZD);安徽师范大学青年基金(2 0 0 2xqn4 0 )资助课题

摘　　要：激光烧蚀等离子体在微量元素分析方面有着重要的应用背景 ,而缓冲气体的种类及压力对激光等离子体的特性有重要影响。报道了以氦气、氩气、氮气和空气作为缓冲气体 ,实验测定了不同气压下Nd∶YAG激光烧蚀Al靶产生的等离子体中的时间分辨发射光谱 ,利用发射谱线的Stark展宽和相对强度计算了等离子体中的电子密度和温度 ,得到了在不同缓冲气体中激光诱导Al等离子体的电子密度随延时、气压的演化规律 ,同时得到了电子温度的时间演化特性。实验结果表明 ,电子密度的数量级约为 10 17cm-3 ,电子温度测量值约为 10 0 0 0K ,二者都是在激光脉冲后随时间快速衰减 ,直到 4 μs以后达到一个较低的水平并缓慢变化 ,其中以氩气作为缓冲气体时等离子体中的电子密度最大。The laser-induced plasma plays an important role in the trace element analysis. The properties of plasma are dependent on the kinds and pressure of buffer gas. With He, Ar, N 2, Air as buffer gases respectively, the time-resolved emission spectra of laser induced Al plasmas at different pressure are measured. The electron density and electron temperature of Nd∶YAG laser-induced Al plasma are calculated by the measured relative emission-line intensity and Stark broadening. The dependence of electron density on the time delay, kinds and pressure of the buffer gas are studied. The time evolution property of the electron temperature is also obtained. The experimental results show that the electron density and the electron temperature in laser induced Al plasmas are the order of 10 17 cm -3 and 10000 K respectively. They are both decayed rapidly with the time delay from the laser pulse off and then changed slowly after 4 μs. Among several of buffer gases, the electron density is the largest in Ar gas.

关 键 词：激光物理 激光等离子体 电子密度 电子温度 发射光谱 时间演化 

分 类 号：TN241[电子电信—物理电子学] O53[理学—等离子体物理]