Electron impact widths of some Ar(II)-u.v.-multiplets

The electron impact widths of 18 Ar(II)-lines, belonging to six different multiplets, have been measured in a steady state, 1 atm arc experiment. These lines are located in the ultraviolet range of the spectrum (250–330 nm) and are observable only at high temperatures (T17,000 K). For comparison, the respective widths have also been calculated according to a simplified expression for the impact broadening of ion lines. With only one exception, excellent agreement between the experimental and the theoretical results is found. In particular, the calculations explain the experimentally observed variation of widths within a multiplet.