Effects of configuration interaction between autoionization and Stark-state resonances

Abstract
Strong interference effects have been found in the electric-field-induced autoionization signal of an isolated, doubly excited bound state in Ba. These interferences arise from interaction with narrow, long-living Stark resonances, which exist degenerately with a quasicontinuum of rapidly ionizing Stark states in the neighboring channel. By comparison with a theoretical model we conclude that the configuration interaction is energy dependent and increases by about a factor of 2 in the center of each Stark resonance.