Speaker
Description
The reaction mechanisms have been investigated intensively in many
reactions with heavy ions. Several processes can take place at the interaction of
two colliding nuclei. The main of them are fusion-fission, quasifission, fast fission,
multinucleon transfer, the formation of the evaporation residue, deep inelastic
collisions and, finally, quasielastic and elastic scattering. A big set of the
experimental data obtained in very different nuclear reactions were measured with
use of double-arm Time-Of-Flight spectrometer CORSET, which allows to
measure binary processes with high accuracy. The experiments were carried out in
FLNR JINR at U-400 and U-400M accelerators, in European scientific centers, but
several experiments were conducted in collaboration with Indian colleagues as
well. The investigated compound nuclei formed in the reactions last from
neutron-deficient 178Pt up to superheavy nucleus with Z=122. Many of the
reactions were measured in wide energy range, below and well above the
Coulomb barrier. The contribution of different processes in the mass-energy
distributions of the reaction products is mainly defined by the entrance channel
characteristics, such like mass asymmetry of the reaction partners, Coulomb factor
(Z1Z2), angular momentum and excitation energy of the compound system, etc. It
was shown that in some cases it is possible to distinguish different mechanisms
and extract their corresponding mass-energy distributions. Moreover, the applied
experimental methods give the possibility to deduce the cross-section values of
different processes. The detailed and complex analysis of mass and energy
distributions of the fusion-fission fragments indicates that not only spherical proton
and neutron shells influence on the behavior of mass and energy distributions, but
deformed proton shells either. In quasifission process which conquers with
fusion-fission the influence of shell effects was also observed. Possible ways of the
set-up development will be also discussed in the presentation. The proposed
upgrade of the spectrometer would significantly enlarge the facilities for
experimental investigations of the reaction mechanisms observed in reactions with
different entrance channel properties, and allow investigations of the structure both
reaction products and evaporation residues.
