Electron Decay-in-Flight Spectra from Autoionizing States of Highly Stripped Oxygen, Fluorine, Chlorine, and Argon Ions

Abstract

We report the results of spectroscopic studies of electrons associated with the decay in flight of metastable autoionizing states in three-, four-, five-, and eleven-electron heavy ions. The binding energies of a large number of observed states are found to be in good agreement with theoretical predictions (c.f. the companion paper of Junker and Bardsley) where such values are available. The lifetime of the lowest-lying quartet state, $(1s2s2p)^{4}P_{\frac{5}{2}}^{o}$ has been measured in three-electron oxygen, fluorine, chlorine, and argon ions. Competition between autoionizing and (in some cases forbidden) radiative-decay modes is discussed. There is evidence that the formation of metastable autoionizing states is quite a general phenomenon, occuring in a wide variety of atomic systems. A need for more extensive energy-level and lifetime calculations is readily apparent.