Self-broadening and shifting of the Li(2s–2p) and K(4s–4p) line cores

✍ Scribed by L. Reggami; M. Bouledroua; A.R. Allouche; M. Aubert-Frécon

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 298 KB
• Volume: 110
• Category: Article
• ISSN: 0022-4073
• DOI: 10.1016/j.jqsrt.2008.09.011

✦ Synopsis

The aim of this work is to determine quantum mechanically the width G and the shift D of the lithium Lið2p ! 2sÞ and potassium Kð4p ! 4sÞ resonance lines when these atoms are evolving in their parent gases. The interaction potentials along which the atoms Lið2pÞ þ Lið2sÞ and Kð4pÞ þ Kð4sÞ approach each other are constructed from reliable data. The radial wave equation is then solved numerically by using these potentials to compute the elastic phase shifts. By adopting the simplified Baranger model for the pressure broadening, which assumes the impact approximation, the cross sections effective in linewidth and lineshift are analyzed. The analysis leads in particular to the determination of the width and shift rates and the computations show that these rates have constant values and, mainly, do not depend on temperature. An approximate method is further applied to the calculations of the cross sections. The results reveal the influence of the long-range ÀC 3 =R 3 interactions and confirm the universality of the obtained formulas of G and D.