Atomic-Beam and Resonance Spectroscopy of Alkali and Alkaline-Earth Atoms

Abstract

During the last few years an extensive program of laser-spectroscopy investigations for sequences of alkali atomic states has been pursued in our laboratory. Very recently two fine-structure investigations were completed. The interesting Cs F-sequence was studied for n = 10−17 in experiments on a collimated beam [1]. With a CW dye laser the 7 ²P_3/2 state was excited, from which about 10 per cent of the atoms cascade to the 5 ²D_5/2 state. A single-mode, electronically tunable laser was then used to scan the ^{5 2}D_5/2 — n ²F_7/2,5/2 transitions. The fine-structure, that is inverted for all the studied F states, can be expressed as an expansion in odd powers of the effective principal quantum number. In addition to collimated-beam measurements, prcision level-crossing determinations of the fine structure for the 5 and 6 ²D K states were performed in a strong external magnetic field [2]. Also using precision values for high-n states, obtained by Gallagher and Cooke [3], an accurate expansion describing the K fine-structure splittings was determined.