Effects of diabaticity on fusion of heavy nuclei in the dinuclear model ...

products. However, in the driving potential calculated with the phenomenological method the
peculiarities <strong>of</strong> the single-particle spectra <strong>of</strong> the DNS nuclei are not taken into account explicitly.
The shell effects in the driving potentials calculated with the TCSM-method and the alter-
native microscopical method reflect the influence <strong>of</strong> peculiarities <strong>of</strong> the single-particle spectra
near the Fermi surface on the nucleon exchange process. For this reason, these driving potentials
can carry more information about the DNS evolution in η than the driving potential calculated
with the phenomenological method. It is obvious that the position <strong>of</strong> the initial configuration
η i defines the evolution direction <strong>of</strong> the DNS in η. The driving potentials calculated with the
TCSM- and with the alternative microscopical methods have few local minima. The absence
<strong>of</strong> local minima for some magic nuclei in the dinuclear system can be explained by the shell
structure <strong>of</strong> the conjugated nucleus and the influence <strong>of</strong> the neutron subsystem.
The effect <strong>of</strong> the deformations <strong>of</strong> the nuclei on the driving potential is presented in Figs.
4-6b) and 4-7b) for the dinuclear systems 180 Hg and 246 Fm, respectively. Here, the driving
potential calculated within the TCSM and the phenomenological potential are shown.We assume
that the deformations take the effects <strong>of</strong> polarisation <strong>of</strong> the nucleus induced by the mean-field
<strong>of</strong> the other nucleus into account. The potential energy <strong>of</strong> the DNS with prolate nuclei is
smaller than the potential energy with spherical nuclei (Figs. 4-6a) and 4-7a) ) because the
Coulomb energy becomes larger for spherical nuclei. In this case, the fusion barrier in η gets
smaller than the one obtained with spherical nuclei. For oblate deformations <strong>of</strong> the nuclei,
the potential energy and the fusion barrier in η are larger than for spherical nuclei. In reality,
some averaging over the orientations <strong>of</strong> the nuclei has to be carried out in the initial DNS.
The deformation effects produce fluctuations <strong>of</strong> the value <strong>of</strong> the fusion barrier in η around the
value obtained for spherical nuclei. In the present version <strong>of</strong> the TCSM, the intrinsic symmetry
axes <strong>of</strong> the deformed nuclei lie along the internuclear axis. For arbitrary orientations <strong>of</strong> the
intrinsic symmetry axes <strong>of</strong> the deformed nuclei, a more general TCSM [81] should be used.
Calculations with the method suggested in [65] reveal a weak dependence <strong>of</strong> the potential on
the orientations <strong>of</strong> the nuclei. In order to completely take into account the deformation effect in
the driving potential calculated with the alternative microscopical method, the single-particle
levels should be taken for deformed nuclei. For the sake <strong>of</strong> simplicity, we use the single-particle
levels <strong>of</strong> spherical nuclei in the present calculations. However, the fit <strong>of</strong> the Fermi surface by the
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