SYNCHROTRON RADIATION STUDY OF PHOTOIONIZATION AND PHOTODISSOCIATION PROCESSES OF O-2 IN THE 12-26 EV REGION

Photoionization and photodissociation of O2 has been studied from the mass selected ions O2+, O+ and O- produced by monochromatic synchrotron radiation of O2 in the 12-26 eV region using the Swedish national synchrotron facility MAX in Lund. The measured ion intensity as a function of the photon energy shows a rich line structure superimposed upon a continuous background. The observed structure is interpreted in terms of autoionization, photodissociation and ion pair formation processes via excited Rydberg states in O2, converging to various low lying O2+ states. Some lines appear in window series which are fitted to the Fano resonance formula.