Oscillator strengths for transitions from excited levels of alkali metal atoms in discrete and continuous spectra

Reviewed are the experimental data on possibilities of optical transitions from excited levels of alkali metal atoms in discrete and continuous spectra. The photoionization process consideration was proceeded by a short review of the latest data for forces of oscillators (theory and experiment) of transitions in supplementary series of alkali atoms. The attention is paid to the fact that in a number of cases the diversion between the experimental and the theoretical results surpasses the limits of experimental error. The material presented may be used for aims of optical diagnostics. Presented are the results of experimental and theoretical investigation of the photoionization from excited levels of alkali metal atoms and discussed is the possibility of application of simplified methods of photoionization cross section - calculation on the basis of hydrogen model. The attention is given to the fact that the large value of the main quantum figure of alkali metal atom excited state alone does not garantee the similarity of the corresponding cross section to a hydrogen one