Spatial diagnostics of the laser-produced tin plasma in air

Abstract

We present here new experimental studies on the laser-produced tin plasma generated by focusing the beam of a Q-switched Nd:YAG laser (532 nm) on the sample in air at atmospheric pressure. The optical emission spectra were recorded with a set of five spectrometers covering the spectral range from 200–720 nm. The electron temperature has been calculated to be about (10 600 ± 600) K using three methods; the two-line ratio, Boltzmann plot and the Saha–Boltzmann plot method, whereas the electron number density of about (9.0 ± 0.8) × 1016 cm−3 has been calculated using the Stark broadened line profiles of tin lines and the hydrogen Hα-line. Furthermore, the branching fractions have been deduced for 15 spectral lines of the 5p5d → 5p2 transition array in tin, whereas the absolute values of the transition probabilities have been calculated by combining the experimental branching fractions with the lifetimes of the excited levels. Our measured values are compared with those reported in the literature and NIST data base, showing good agreement.