Collision Broadening of Principal Series Lines of Barium in the Presence of Krypton

Abstract
Spectral line broadening of barium 6 s 2 1 S 0 -6 s n p 1 P 1 ( n =7 to 18) transitions has been observed by the total absorption method. Absorption oscillator strengths of these lines have been determined by the hook method. The measured broadening cross section increases from 0.9 to 6.5×10 -13 cm 2 as n increases from 7 to 10, and then decreases to reach a small fraction of its maximum (∼2×10 -13 cm 2 for n ≥13); this n -dependence shows no definite irregularity as seen for the measured oscillator strengths.