The hot fusion is a frequently used way to produce exotic nuclei. There are many experimental data concerning e.g. total and differential fusion cross-sections, spin distributions, multiplicites of particles emitted during fusion process or deep inelastic collision. These data should be compared with results of theoretical calculations.
The theoretical description of the heavy ion collisions at energies of the
order of few hundreds MeV would be of great interest for studying
the validity of the transport equation. At these energies the
fused system will reach the temperature of 4-5 MeV and such a high
temperature will influence:
The heights of the fusion and fission barriers;
The magnitude of the friction forces;
The value of the diffusion and the mass tensors.
The change of the fusion barrier with temperature could be estimated
within of the extended Thomas-Fermi (ETF) method applied to the Skyrme
interaction. The ETF model predicts a significant
decrease with temperature of the surface term in the liquid drop energy,
while the Coulomb part is almost unchanged. The temperature dependence
of the friction forces was extensively discussed within the linear
response theory and other microscopic theories. All theoretical
models predict an increase of the friction forces with temperature
and saturation at higher temperatures. Also the commonly used Einstein
relation between the diffusion and the friction forces should be tested
in the wide range of temperatures. The last theoretical works
suggest that the Einstein relation should be modified.
Theoretical investigation of multifragmentation process.
A model of dynamical instabilities of finite, hot, expanding nuclear
droplets is developed. The model accounts for small amplitudes
density and surface isoscalar modes that become unstable for
nuclear densities below 0.5-0.6 times the normal nuclear density.
Adiabatic and diabatic evolution is considered.
We plan to extend the model for isovector modes and
include dissipation.