CLASSICAL-THEORY OF L-CHANGING TRANSITIONS IN COLLISIONS BETWEEN RYDBERG ATOMS AND IONS

The l-changing transitions in collisions of Rydberg atoms with ions, A (nl(0))+B+-->A(nl)+B+, are considered within the classical approximati on for atomic electron motion. The elliptic orbit of the electron evol ves slowly under the influence of the time-dependent electric field ex erted- by the incident ion. The quantum electron state is represented by an ensemble of classical trajectories. Within the dipole approximat ion extremely simple analytical formulas for the final-state l-distrib ution function are obtained for a fixed value of the impact parameter. The influence of the non-coulomb core is taken into account approxima tely. The results of our calculations compare favorably with recent ex perimental data for the Na+(26d, 28d) Rydberg atom. The method can be extended to the calculation of distributions over various observables other than l.