The 90° electron spectra from oxygen-ion single collisions with Ar have been measured at energies of 17 to 41 MeV and charge states of 3+ to 8+. A broad peak in the spectra is observed and identified as electrons lost from the incident ion. A simple model of the electron-loss process is described which supports the identification.

• Received 19 March 1973

DOI:https://doi.org/10.1103/PhysRevLett.30.823