Doublet line-strength ratios for the principal series of cesium

Space-charge amplification of the indirect ionization resulting from photoabsorption in cesium vapor has been shown to offer to conventional techniques of absorption spectroscopy a useful complement of highest sensitivity. It was used in this work together with a xenon continuum source filtered to a linewidth of 0.14 Å to measure the relative absorption probabilities for transitions of the cesium-principal-series (6²S-n²P_1/2,3/2) doublets. Anomalous pressure effects on the resulting line-strength ratios, resulting in part from polarization molecules of Cs₂*, were examined over a range of cesium-atom concentration varying from 1.2×10¹⁴ to 1.5×10¹⁵ cm^-3. From the corrected doublet line-strength ratios for 11≤n≤16, the segment of the curve of Fano X parameters corresponding to discrete energies was constructed. Interpolation between these results and those from electron-polarization experiments served to locate the pole in the principal-series, doublet line-strength ratio near 19²P.