STARK MIXING OF DEGENERATE STATES

The initial value problem and the field dressing associated with the t ime-dependent Stark effect are treated, which are of importance in app lications. An exact solution of time-dependent field mixing of degener ate states as an initial value problem is obtained in the restricted s ubspace of a given principal quantum number of hydrogenic ions, with t he field-dependent phases explicitly included. The field mixing in ter ms of the transformation from spherical to parabolic representation is clarified. The distinction between these two problems is stressed and previous work on the field-perturbed dielectronic recombination is re -examined.