The O Kα and C Kα emission and O K absorption spectra from O2 and CO2. IV

The oxygen and carbon Kα emission and oxygen K absorption spectra of the molecular gases O2 and CO2 are reported. The spectra were obtained on two different spectrometers, both with single flat crystal configurations. All the emission spectra were excited by direct electron bombardment and are in fair agreement with an interpretation based on allowed electric dipole transitions between single vacancy states and molecular orbital theory for the molecules. The oxygen K absorption of O2 and CO2 is dominated by a strong resonance peak before the K-shell threshold which is interpreted as being due to the transition of oxygen K electrons to the first unoccupied valence orbital of the respective molecules.