  In the past years, the interest in the laser-driven acceleration of heavy
ions in the mass range of A ~ 200 has been increasing due to promising
application ideas like the fission-fusion nuclear reaction mechanism, aiming at
the production of neutron-rich isotopes relevant for the astrophysical
r-process nucleosynthesis. In this paper, we report on the laser acceleration
of gold ions to beyond 7 MeV/u, exceeding for the first time an important
prerequisite for this nuclear reaction scheme. Moreover, the gold ion charge
states have been detected with an unprecedented resolution, which enables the
separation of individual charge states up to 4 MeV/u. The recorded charge-state
distributions show a remarkable dependency on the target foil thickness and
differ from simulations, lacking a straight-forward explanation by the
established ionization models.
