Electron impact excitation of inner-shell excited states of CO

The design of an electron impact spectrometer for use in inner-shell studies of atoms and molecules is described. The use of the spectrometer to investigate inner-shell excited states of CO is reported. These states include the lowest lying valence states, (1s sigma C ) -1 (2p pi ) 1 Pi and 3 Pi , Rydberg states below the 1s C ionisation potential and doubly excited states above the ionisation potential.