Electron impact broadening of ionized chlorine lines

A pulsed arc in dichlorodifluoromethane was the source of a plasma used to measure, on a shot-to-shot basis, profiles of 33 lines of singly ionized chlorine. An electron density of 6.80 and 5.03*10¹⁶ cm^-3 was determined by the laser interferometry at a single wavelength, while electron temperatures 18600 K and 14500 K were measured from relative intensities of Cl II lines. The experimental Cl II Stark profile half-halfwidths were compared with theoretically calculated values. A systematic and increasing discrepancy between experimental and theoretical values, computed from Griem's semiempirical formula, for the lines of Cl II multiplets with the energy levels approaching the ionization threshold was found.