Photoelectron and photoion study of the valence photoionization of C60

Abstract

Recent photoion yield measurements, done in the valence photoionization region of C60, reveal a high fraction of doubly and even triply charged ions [see A. Reinköster, S. Korica, G. Prümper, J. Viefhaus, K. Godehusen, O. Schwarzkopf, M. Mast, U. Becker, J. Phys. B: At. Mol. Opt. Phys. 37 (2004) 2135]. The Click to view the MathML source intensity increases continously up to hν≈60 eV and stays constants at higher photon energies. Moreover, the fragmentation into Click to view the MathML source and Click to view the MathML source is pronounced in the energy region hν≈50–70 eV. The question arises, if after electrons are removed from certain electronic levels, the multiple-ionization or even the fragmentation is somehow triggered. Or in other words, if the multiple-ionization or the fragmentation characteristics can be already seen in the simple (non-coincident) electron data. We can answer the question with the help of such non-coincident valence electron measurements, recorded in the interesting photon energy region hν≈40–70 eV