Pressure Effects of Foreign Gases on the Absorption Lines of Cesium. III. The Effects of Krypton

The effect of Kr on both fine-structure components of the first four members of the principal series of Cs is described with particular attention paid to the low-pressure region. The most detail is given for Cs(1)/Kr, where the pressure range extended to 80 atm. In addition, the shift of the peak of the ${}_{}{}^2{}_{}{}^{}P_{\frac{3}{2}}^{}{}_{}{}^{}$ component up to Cs(20) inclusive was measured at low pressures only. The peak-shift measurements showed that for low series members the shift is linear with relative density of Kr at low pressure; as the pressure increases there is a transition region and then a second linear region. As the series member gets higher, the first linear region and the transition region shrink. For series member lines higher than Cs(5), only the second linear region was observable. Very nonlinear half-widths are observed for low series members. In many respects, the data obtained for Cs/Kr are very similar to those obtained for Cs/Ar.