Measured stark widths of several Sn I and Sn II spectral lines in a laser-induced plasma

Abstract

Data on Stark widths of spectral lines are of high interest for astrophysics and analytical techniques of stellar plasma diagnosis. Stark widths of 43 spectral lines of Sn I and 27 spectral lines of Sn II has been measured in a laser-induced plasma (LIP) at an electron temperature of 11,000 K and an electron density of 1.1x10¹⁶cm-³. The LIP optical emission spectroscopy generated by a 10640 Å radiation, with a flux of 1.4x10¹° W cm-² on several tin and lead targets in an atmosphere of argon was recorded at 2.5 µs and analyzed between 1890 and 7000 Å. The population level distribution and the corresponding temperatures were obtained using Boltzmann plots. The plasma electron densities were determined using well-known Stark broadening parameters of spectral lines. Special attention was dedicated to the possible self-absorption of the different transitions. The local thermodynamic equilibrium (LTE) conditions and plasma homogeneity have been checked. The experimental results obtained have been compared with the experimental and theoretical values given by other authors. The results obtained in this study will allow a substantial improvement in the interpretation of the data of the ultraviolet spectrum of the tin observed by the Goddard High Resolution Spectrograph aboard the Hubble Space Telescope. These atomic data are relevant to the analysis of the isotopic abundances of tin in stellar atmospheres.