Blue asymmetry of potassium resonance lines broadened by caesium atoms

The authors have measured the absorption efficient in the quasi-static wings of the first potassium resonance lines in various K-Cs mixtures. At sufficiently high concentrations of caesium atoms both components of the potassium first resonance doublet have extended blue wings of the van der Waals type. The corresponding effective C6 constants determined from the experimental data are (1.5+or-0.3)*10-29 s-1 cm6 and (2.4+or-0.5)*10-29 s-1 cm6 for the stronger and weaker components, respectively. The calculated values of the effective C6 constants are 1.78*10-29 s-1 cm6 for the stronger component and 2.35*10-29 s-1 cm6 for the weaker component.