Stark broadening of isolated lines emitted by singly-ionized tin

Calculations have been performed on the electron impact broadening of isolated lines from singly-ionized tin from a cool plasma. These have been compared with results of measurements recently performed by Miller, Roig, and Bengtson on a plasma produced by a conventional shock tube, and satisfactory overall agreement has been obtained. Our method is similar in procedure to that of the semi-empirical approximation of Griem, but we take into account the details of the radiator structure, including configuration interaction for two of the terms. We propose a new expression from which the relevant effective Gaunt factors for singly-charged ions can be calculated for incident energies above threshold. In some cases, a significant variation of line width within multiplets is noted. Some difficulties have been experienced with transitions to states involving equivalent electrons.