Plasma broadening and shifting of spectral lines along the isoelectronic sequence of boron.

Abstract

Temperature dependence of the Stark widths (N III and F V) and shifts (N III and O IV) of the 3${\mathit{s}}^{2}$S-3p${(}^{1}$S${)}^{2}$${\mathit{P}}^{0}$ and 3${\mathit{p}}^{2}$${\mathit{P}}^{0}$-3d${(}^{1}$S${)}^{2}$D transitions have been studied theoretically using the impact semiclassical method and experimentally observed in the plasma of a low pressure pulsed arc. Plasma electron densities were determined from the width of the He II ${\mathit{P}}_{\mathrm{\ensuremath{\alpha}}}$ line while electron temperatures were measured from the relative line intensities. To estimate the influence of different ions on the width and shift of lines, evaluations of the plasma composition data were performed and, in conjunction with our theoretical results, the contribution of ion broadening was estimated. Within the estimated uncertainties experimental Stark widths agree well with the results of our semiclassical electron impact widths in the studied electron temperature range. For the conditions of the present experiment, estimated contribution of the ion broadening has never exceeded five percent of the total width. So within the precision of this experiment it was not possible to detect its presence with certainty. Along the boron isoelectronic sequence the experimental widths and shifts agree with semiclassical electron impact data predictions. In the case of O IV lines the inclusion of the energy levels with different parent terms in our semiclassical calculations of the Stark widths and shifts improved the agreement between theory and experiment considerably. Comparisons of the experimental widths with simple theoretical formulas for estimation of plasma broadened linewidths show an agreement within estimated uncertainties. \textcopyright{} 1996 The American Physical Society.