Vanishing effect in post-collision interaction during photon-excited Coster-Kronig decay.

In radiationless transitions to atomic inner-shell hole states produced by threshold photoionization, the Auger electron energy is shifted up by post-collision interaction between the two continuum electrons. According to both semiclassical and quantum-mechanical models, this shift is expected to disappear if the photoelectron energy exceeds that of the Auger electron (the vanishing or ''no-passing'' effect). This effect, recently observed for a long-lived (4d) hole state of Xe, is now also demonstrated for the very fast Xe L/sub 2/-L/sub 3/N/sub 4/ (J = 3) Coster-Kronig transition, excited with synchrotron radiation.