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 C 6 constants determined from the experimental data are (1.5+or-0.3)*10 -29 s -1 cm 6 and (2.4+or-0.5)*10 -29 s -1 cm 6 for the stronger and weaker components, respectively. The calculated values of the effective C 6 constants are 1.78*10 -29 s -1 cm 6 for the stronger component and 2.35*10 -29 s -1 cm 6 for the weaker component.