The broadening of d-f and f-d transitions
by collisions with neutral hydrogen atoms
P.S. Barklem, B.J. O'Mara and J. E. Ross
Department of Physics, University of Queensland, St. Lucia 4072, Australia
ABSTRACT
The theory of Anstee & O'Mara (1991,1995) for the broadening of spectral lines due to collisions by neutral hydrogen atoms is extended to d--f and f--d transitions of neutral atoms. Width cross-sections are tablulated against effective principal quantum numbers for the upper and lower states of the transition, for a relative collision velocity of 10000 m/s. The cross-sections are fitted to a variation with velocity of v^-alpha, and results for the velocity parameter (alpha) are similarly tabulated. The data is tested by application to d--f spectral lines in the solar spectrum. The derived abundances are consistent with those for meteorites.