Effect of Spectral Line Self-Absorption on the Laser-Induced Plasma Diagnostics

Abstract

In this paper, we propose and use an experimental method permitting the measurement of optical depth of a selfabsorbed spectral line emitted from laser-induced plasma on the surface of an aqueous solution. Using well-known equations describing the radiatif transfer and the evolution with the optical depth of the relative uncertainty on the measurement of line intensity and on the half width at half maximum, we have also deduced the uncertainty on the measurement of electron temperature and the electron density. An application to the diagnostics of this plasma has been realized, and we show the reliability of the spectroscopic measurements.

The comparison of manganese spectral lines for self-absorption reduction in LIBS using laser-induced fluorescence

“…Additionally, LIBS experimental system parameters, such as laser parameters, plasma spatiotemporal resolution parameters, and atmosphere parameters, will all affect the self-absorption effect. Therefore, several other researchers mitigated self-absorption by adjusting the experimental conditions [18][19][20][21]. For a particular spectral line, reducing both the lower-level particle number density (n i ) and the absorption path length (l) can reduce the self-absorption effect [22].…”