Stark profiles of forbidden and allowed transitions in a dense, laser produced helium plasma

Abstract

Comparisons of experimental and theoretical Stark profiles of the allowed 2¹P-3¹D helium line at 6678AA and of the forbidden 2¹P-3¹P component at 6632AA in a dense plasma were carried out. The plasma was produced by optical breakdown of helium by means of a repetitive, high power CO₂ laser. The allowed line shows good agreement with conventional theory, but discrepancies are found around the centre of the forbidden component. When normally neglected ion motions are taken into consideration, the observed discrepancies are partially removed. Tables of the Stark profiles for the pair of lines are given for electron densities in the range 3*10¹⁵-3*10¹⁷ cm^-3 and temperatures in the range 10000-40000K.