PARTIAL CROSS SECTION MODULATIONS IN C$_{60}$: EXTENDED
MEASUREMENTS
A. Ruedel, R. Hentges, and U. Becker
Fritz-Haber-Institut der Max-Planck-Gesellschaft,
Faradayweg 4-6, 14195 Berlin, Germany
Valence photoionisation cross sections of the two outermost
orbitals of C$_{60}$ were measured up to 290 eV photon energy.
The results show a continuation of the quantum oscillations
known for lower photon energies towards higher energies with first
clear indication for an enveloping beating frequency in the
rapidely oscillating branching ratio HOMO/HOMO-1. The results
are interpreted in terms of a semiempirical model based on
effective potential with finite widths $\delta$ arround the
C$_{60}$ cage.