Determination of excitation temperature in laser-induced plasmas using columnar density Saha-Boltzmann plot
Authors: Safi A., Tavassoli S.H., Cristoforetti G., Legnaioli S., Palleschi V., Rezaei F., Tognoni E.
Autors Affiliation: Laser and Plasma Research Institute, Shahid Beheshti University, G. C., Evin, Tehran, Iran; National Institute of Optics of the National Research Council (INO-CNR), Via G. Moruzzi 1, Pisa, Italy; Applied and Laser Spectroscopy Laboratory, Institute of Chemistry of Organometallic Compounds, Research Area of National Research Council, Via G. Moruzzi, 1, Pisa, Italy; Department of Physics, K. N. Toosi University of Technology, Tehran, 15875-4416, Iran
Abstract: In exploiting the analytical capabilities of plasma-based spectroscopy method, the evaluation of plasma parameters, particularly the plasma temperature, is a crucial step. In this work, a modified Saha-Boltzmann plot, which uses the columnar densities of atomic and ionic ground levels, is utilized to calculate the plasma temperature in a laser-induced plasma from an aluminum alloy target. The columnar densities are here calculated by quantifying the self-absorption of resonance lines. It is demonstrated that this is a promising method for accurate determination of plasma temperature. To validate the capability of this technique, plasma emission is measured at different gate delay times. For each delay, excitation temperature is calculated both by the conventional Saha-Boltzmann plot (by using the excited states) and by exploiting the new Columnar Density Saha–Boltzmann (CD-SB) plot. The results suggest that at later times of the plasma evolution, the CD-SB plot can be more suitable for the determination of plasma temperature than conventional Saha-Boltzmann plot. These findings provide a new approach for physical characterization of plasmas and give access to a wealth of information about the state of plasma.
Journal/Review: JOURNAL OF ADVANCED RESEARCH
Volume: 18 Pages from: 1 to: 7
More Information: Abdus Salam International Centre for Theoretical Physics, MINDEF. – Financial support for this research provided by ‘ ICTP Program for Training and Research in Italian Laboratories, Trieste, Italy’ is gratefully acknowledged.KeyWords: Excitation temperature; LIBS; Plasma; Saha-Boltzmann plot; Self-absorption; SpectroscopyDOI: 10.1016/j.jare.2019.01.008Citations: 2data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2020-07-05References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here