Stark width and shift temperature dependence of the Ar I 425.9 nm line

Abstract

We report measured Stark widths and shifts of the neutral argon 425.9 nm line. A wall stabilized arc is used as a plasma source. Electron densities of 0.5 − 3.5 × 10 22 m −3 are determined from the width of the H β line and electron temperatures of 9000-11,000 K are deduced from plasma composition data. Measured Stark widths and shifts are systematically smaller than semi-classical theoretical results. Comparison of the experimental Stark widths and shifts with theoretical data shows gradual increase of the discrepancy with temperature. This is more distinctive in the case of shifts.