Open AccessComparative study on self-absorption of laser-induced tungsten plasma in air and in argon
Author(s) -
Ran Hai,
Zhonglin He,
Xiao Yu,
Liying Sun,
Ding Wu,
Hongbin Ding
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.002509
Subject(s) - materials science , argon , laser , laser induced breakdown spectroscopy , plasma , absorption (acoustics) , absorption spectroscopy , fluence , tungsten , tunable diode laser absorption spectroscopy , plasma diagnostics , nanosecond , spectroscopy , ultrafast laser spectroscopy , optics , emission spectrum , atomic physics , analytical chemistry (journal) , spectral line , chemistry , physics , quantum mechanics , astronomy , chromatography , metallurgy , composite material
The onset of self-absorption of laser-induced plasma poses a problem for converting emission line intensities to concentrations, which is one of the main bottlenecks in quantitative laser-induced breakdown spectroscopy (LIBS) measurements. In this paper, the effects of atmosphere and laser fluence on self-absorption reduction of the plasma induced on tungsten-copper alloy target were investigated with nanosecond infrared (1064 nm) laser pulse over a range of 2.9 to 18.2 J/cm 2 . The time-resolved features of self-absorption, and temperature and electron density of the plasma were characterized in atmospheric air and argon, respectively. The experimental results show the effect of self-absorption can be significantly reduced by increasing the laser pulse energy. The argon atmosphere is more helpful for self-absorption reduction. The time-resolved diagnostics of emission spectra in the early stage of the plasma formation are very effective to prevent self-absorption to improve the LIBS analytical performance.