MAGNETOOPTICAL SPECTRA OF LITHIUM AND SODIUM

New measurements of Faraday rotation spectra for the elements lithium and sodium are reported. The observed patterns are all obtained and analysed under full Paschen-Back coupling conditions. These are believed to be the first accurate measurements for these elements extending to high principal quantum numbers. The course of f-values in the principal series is compared with available calculations, which take account of core polarization effects by the quantum defect orbital method. Our measurements reveal that the influence of the magnetic field on the f-values of the high series members grows as B2n4. When this is corrected for, our data extrapolate to absorption cross sections in the base of the continuum which agree well with earlier measurements. We also apply this correction to our earlier data for potassium.