Four-photon ionisation in Cs I near the 6f resonance

Abstract

Presents the first application to a physical case of the effective-operators method introduced by Armstrong, Beers and Feneuille (1975) to interpret resonant multiphoton ionisation. In particular, the four-photon ionisation of Cs I near the 6f resonance is considered. Atomic quantities needed for the evaluation of effective operators are obtained by using a non-relativistic central-potential model. Theoretical results are compared with experimental data recently obtained by Morellec, Normand and Petite (1976). Taking into account the uncertainty of the measurements, the main experimental features and, in particular, the shapes of the resonance curves are reproduced well by the calculation described here.