The broadening of p-d and d-p transitions
by collisions with neutral hydrogen atoms
P.S. Barklem and B.J. O'Mara
Department of Physics, University of Queensland, St. Lucia 4072, Australia
ABSTRACT
The collisional broadening theory of Anstee & O'Mara (1991,1995) for s-p and p-s transitions by collisions with atomic hydrogen is extended to p-d and d-p transitions.
Width cross-sections for collisional broadening of atomic lines corresponding to p-d and d-p transitions by neutral hydrogen atoms are tabulated as a function of effective principal quantum numbers for the upper and lower states, for a relative velocity of 10000 m/s. The cross-sections vary with velocity as v^(-alpha), and results for the parameter alpha are similarly tabulated.
The cross-sections are tested by application to synthesis of suitable strong solar lines. The derived abundances are consistent with meteoritic values.