Relative abundances and recoil energies of fragment ions formed from the x-ray photoionization of N2, O2, CO, NO, CO2, and CF4

A specially designed mass spectrometer has been used to study the fragment ions following x-ray photoionization of several simple gaseous molecules, containing only first-row elements. Two photon sources were used: CuLα (930 eV) and CKα (280 eV). The higher-energy x-ray source produced initial vacancies primarily in the K shells of the different elements, while the lower-energy radiation produced ionization entirely in the valence shells. Data were obtained as a function of collection voltage, and relative abundances of the fragment ions were evaluated under conditions of equal collection efficiency. From the shape of the collection efficiency curve the average recoil energies were estimated. The results are briefly discussed in terms of the effect of the KLL Auger processes and multiple ionization.