PRODUCTION OF METASTABLE AR-IMPACT IONIZATION OF AR MEASURED BY TRANSLATIONAL-ENERGY SPECTROSCOPY( IONS BY ELECTRON)

The translational-energy-spectroscopy technique has been used to measu re the apparent ionization-excitation functions for the metastable sta tes 3d 4D, 3d 4F, 3d 2F, and 3d'2F of an Ar+ ion beam extracted from a n electron-impact ion source. The initial states were identified from the measured energy loss in the translational-energy spectra for singl e-electron stripping from ground-state and metastable Ar+ ions in coll isions with O2. This technique provides an alternative method of selec tivity in the study of electron-impact ionization and excitation proce sses.