Broadening of the Lyman-βline of hydrogen by low-frequency fields in dense plasmas

Abstract
A previously developed extension of the quasistatic approximation for the broadening of the Lyman-α line is applied to Lyman β. This extension allows for slow variations of the total field acting on a radiating atom. The corresponding low-frequency Stark broadening depends on the radiator velocity and is therefore correlated with the thermal Doppler broadening. With the low-frequency field correction, a major disagreement with experiment near the center of the Lyman-β line is removed. Corresponding corrections for lines from high-Z hydrogenic ions are also estimated.