激光诱导Al等离子体中的Doppler效应  

Doppler Effect on Width of Characteristic Line in Plasma Induced by Pulsed Laser Ablating Al

作　　者：宋一中[1] 贺安之[1] 

机构地区：[1]南京理工大学理学院

出　　处：《光谱学与光谱分析》2005年第5期655-659,共5页Spectroscopy and Spectral Analysis

基　　金：中国博士后科学基金(2004036121);山东省科技计划立项课题(J04A63)资助

摘　　要：用Nd:YAG脉冲激光烧蚀Al靶产生等离子体,利用时间分辨技术采集Al等离子体辐射的时间分辨信息,使用光学多道分析系统(OMAⅢ)记录Al等离子体辐射光谱,从而获得激光诱导Al等离子体时间分辨光谱。分别利用Lorentz函数、Gauss函数以及这两种函数的线性叠加函数(后简称叠加函数),对Al原子共振双线AlⅠ396.15nm,AlⅠ394.40nm进行拟合分析,解析出实验谱线所含的Lorentz和Gauss线形成分。通过对比这两种线形成分发现,实验谱线主要由Lorentz线形成分所组成,Gauss线形成分相对少得多。通过对比Lorentz函数与叠加函数对实验谱线的拟合曲线,给出了Doppler效应展宽谱线的直观图像,估算了Doppler效应导致谱线的增宽量。结果发现,Doppler效应引起的Al共振谱线增宽约2×10-3～8×10-3nm,这与理论计算结果6.7×10-3nm符合得很好。因此,通过拟合分析与理论计算,对激光诱导Al等离子体中的Doppler效应给以圆满解释。Aluminum (Al) plasma was induced with a pulsed Nd: YAG laser beam ablating Al target in Ar. Time-resolved information of the plasma radiation was taken with time-resolved technique, and the spectra of the radiation were recorded with an optical multi-path analyzer (OMA III), whereupon, time-resolved spectra of the plasma radiation induced by pulsed laser were acquired. Based on the experiment data, Al resonant double lines, Al I 396.15 nm, Al I 394.40 nm, were respectively fitted with Lorentz, Gauss and their linear integrated function (abbr. Integrated function), whereupon, Lorentz and Gauss elements were separated from the experiment data profile curve. By contrasting Lorentz with Gauss curve separated, it was found that the experiment curve mainly consisted of Lorentz element, a with little Gauss. By contrasting Lorentz with Integrated fitting curve for experiment data, a visual picture of the characteristic lines broadened by Doppler effect was exhibited. According to the visual picture, the increase of full half-high width of the characteristic line broadened by Doppler effect was estimated. It was about 2 X 10(-3) -8 X 10(-3) nm, approximating the theoretical value 6.7 X 10(-3) nm. As a result, Doppler effect on the width of characteristic lines in the plasma could be reasonably explained by curve fitting analysis and theoretical calculation.

关 键 词：Doppler效应 时间分辨光谱 拟合分析 谱线半高全宽 谱线增宽 

分 类 号：O532.2[理学—等离子体物理]