Kinetic energies of fragment ions from N2absorbing soft X-rays by a photoion-photoion coincidence technique

Dissociative ionisation of N 2 induced by soft X-ray absorption has been studied using a photoion-photoion (PIPICO) coincidence technique. Photon-energy dependences of the yields dissociating into N + +N + and N + +N 2+ have been measured. Kinetic energies of these ions have been obtained by analysing the PIPICO spectrum at high resolution. The dissociation processes are discussed on the basis of their kinetic energies and the energy levels of N + , N 2+ , N 2 + and N 2 2+ .