Positive and negative ion desorption induced by photon impact (10–100 eV) on condensed gases

Abstract

Singly and doubly charged ion desorption from condensed argon is studied by photon excitation in the 10–100 eV energy range. The ion yield curve and threshold energy measurements indicate that multiple excitation or ionization processes, such as formation of satellite states and double or triple photoionization, are the dominant primary electronic processes. Negative ion (O −) desorption from condensed oxygen as produced by photon impact in the 17–38 eV range is also reported. The observation of resonant processes suggests that molecular Rydberg states of adsorbed O 2 molecules may contribute to the desorption mechanism.