Time-resolved emission spectroscopy in laser-generated argon plasmas—determination of Stark broadening parameters

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• 作者：Cadwell ; L. ; Hü ; wel ; L.
• 关键词：Optical breakdown ; Plasma ; Stark broadening ; Argon
• 刊名：Journal of Quantitative Spectroscopy and Radiative Transfer
• 出版年：2004
• 出版时间：February 1, 2004
• 年：2004
• 卷：83
• 期：3-4
• 页码：579-598
• 全文大小：568 K

文摘

We have investigated time-resolved emission spectra of neutral argon lines in a pulsed laser-generated argon plasma source at atmospheric pressure. Depending on time after spark ignition, electronic excitation temperatures between roughly 5600 and 9600K are observed. Electron density values between 0.6 and 2.3×10¹⁶cm⁻³ are determined from Griem's theory of Stark-broadened line shapes as applied to the 703.025nm emission line of argon. An examination of the influence of spatial averaging on temperature and electron density values indicates that for our extended plasma source only the hottest core region contributes significantly to the signal. Therefore, despite the obvious spatial inhomogeneity of the plasma source, the reported parameter values can be attributed to a plasma region where conditions vary only weakly. Within this framework, the electron contribution to the Stark-broadening parameters of 12 neutral argon lines is obtained with an estimated overall average uncertainty of about 20 % . Our work demonstrates that laser produced plasmas can be used as a simple and versatile source to extract reliable Stark-broadening parameters.