Calculated Electron and Ion Stark Broadening of the Allowed and Forbidden 2^{3}P-4 ^{3}P, ^{3}D, ^{3}F Transitions in Neutral Helium
Abstract
Profiles of the line of He i at 4471.48 A (2 3P-4 3D) inclusive of the forbidden component at 4470.04 A (2 3P-4 3F) are derived, using the quasi-static approximation to account for the perturbing ions and the impact approximation as generalized for overlapping lines to describe the electron effects The influence of the 4 3P level is considered as a further perturbation, but broadening of the 2 3P levels is neglected. Tabulated profiles of the line absorption coefficient are presented which, in addition to Stark broadening, allow for fine structure of the lower levels and thermal Doppler broadening. For low electron densities, asymptotic formulas are proposed, together with suitably weighted and displaced Doppler profiles
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1968
- DOI:
- 10.1086/149830
- Bibcode:
- 1968ApJ...154.1111G