Oxygen beam gas Auger electron emission

High resolution Auger electron emission spectra for oxygen ion beams excited by single collisions with noble gases were measured. Electrons ejected from the oxygen ion-monatomic gas collision region at a mean laboratory emission angle of 23.70 were recorded with a 36 cm double focussing electrostatic electron analyzer (transmission function, ΔE/E, = 0.02 percent full-width-at-half-maximum). The Auger electron decay-in-flight of oxygen ions was studied as a function of exciter gas (helium, neon, argon, and krypton), incident ion energy (2 to 30 MeV), and incident ion charge state (1+ to 4+). Increased multiple ionization and enhanced line broadening was observed for heavier exciter gases and higher incident beam energies, but little incident ion charge state dependence was detected. Resolution for these measurements is limited by instrumental line broadening due to the finite acceptance angles of the spectrometer. The relative importance of the effects which contribute to Auger electron line broadening is discussed