Measured Stark widths of several Ni II spectral lines

Abstract

The Stark broadening parameters of 17 lines of Ni II have been measured in a plasma produced by ablation of an Al–Ni alloy with a Nd:YAG laser. The broadening parameters were obtained with the target placed in molecular argon at 6 Torr, which provides appropriate measurement conditions. A Boltzmann plot was used to obtain the plasma temperature (16 500 ± 2100 K) and published values of the Stark broadening in Al II to obtain the electron density ((1.07 ± 0.10)1017cm−3); with these values, the plasma composition was determined by means of the Saha equation. The local thermodynamic equilibrium condition was checked. Contributions to broadening arising from a mechanism different from the Stark broadening as well as self-absorption influence were estimated for every studied line. A comparison was made with previous experimental values and recent theoretical estimates of the Stark broadening where possible.