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Information × Registration Number 0220U101298, 0118U001609 , R & D reports Title Nuclear collective dynamics for high temperatures and neutron - proton asymmetries popup.stage_title Head Magner Oleksandr G., Доктор фізико-математичних наук Registration Date 07-02-2020 Organization Institute for Nuclear Research of NAS of Ukraine popup.description2  Research subject is dissipative properties of nuclear-nuclear collisions within the kinetic, hydrodynamic and statistic approaches. Research methods are based on Boltzmann and Langevin equations of the collective dynamics, and on equilibrium and non-equilibrium statistical physics. The purpose is to study the dissipation of collective excitations, properties of nuclear superheavy fission, equation of nuclear matter state, and isotopic instability versus non-equilibrium parameters at extremal temperatures and neutron-proton asymmetries. Basic results: (1) the absorption coefficient for collective excitations of particle gas is an universal function of Knudsen parameter, independent of the particle mass and size, and of the characteristics of equilibrium state, - system temperature and particle number density; (2) absorption coefficient has a maximum for the transition from the frequent to rare collision regime; (3) role of the non-markovian dissipative effects in the rate of the induced nuclear fission is the stronger the larger temperature of the initial equilibrium state; (4) mass distributions of fission fragments is strongly changed from the mass-symmetrical to the mass-asymmetrical behaviour while the dependence on energy excitations is relatively slow; (5) mean values of the total kinetic energy are increased with increasing of the mass number of nucleus; (6) critical points of nuclear matter within the van der Waals model improved by quantum statistics effects in the first approximation of the perturbation theory are significantly changed in good agreement with accurate theoretical and experimental results; (7) chemical instability conditions restrict possible limits for existence of nuclear matter in temperatures and neutron-proton asymmetries. Our results can be applied in the BITP NAS of Ukraine, GSI of Germany, CERN of Switzerland, and JINR of Russia. Product Description popup.authors popup.nrat_date 2020-04-02 Close