Cherevko K. Thermodynamics of the surface phenomena and fragmentation in the nuclear matter

This scientific work addresses the problem of the thermodynamics of interfaces and fragmentation of the nuclear matter. Thermodynamic properties of the curved interfaces are studied in details. Theoretical models of the fragmentation phenomena that account for the addends in the surface tension coefficient connected with the surface curvature are developed. The methods of the equilibrium and non-equilibrium statistical thermodynamics are used to develop the novel thermodynamic approach based on the Gibbs-Tolman formalism that allows for evaluating the curvature correction to the surface tension coefficient in the nuclear matter in case of the Skyrme type energy density functional. Based on the properties of the equation of state of nuclear matter the link of the bulk and surface properties is shown. Within the introduced model the dependence of the curvature correction to the surface tension coefficient on temperature is found. It is shown that the qualitative behavior in a wide temperature range is similar to that of the ordinary liquids. The possibility to use the curvature correction term to the surface tension as a criterion for the efficiency of the Skyrme interaction in describing surface properties is studied. It is shown that not all the existing parametrizations are capable to describe adequately the interphase interfaces in nuclear matter. The known thermodynamic relations for ordinary liquids are used for the nuclear-system formed in the proton-induced multifragmentation phenomena in order to analyze its possible evolution pathways in the P-V plane. A number of decay channels suggesting the most appropriate qualitative picture are proposed. The analysis of the quantitative characteristics of the reaction channel that involves the “mechanical” breakdown of the “cold shell” due to the increased pressure in the inner part of the system suggests that on the macroscopic level it meets the necessary conditions for describing the proton-induced multifragmentation phenomena. The possibility to apply the hydrodynamic description for the description of the heavy ion collisions at intermediate energies. Self-consistent theoretical model of the collisions introduced. The model suggests that one can define four distinct stages of the collision. Among them are the violent stage at the beginning of the process when the highly compressed zone is formed and the second stage that is characterized by the lateral jetting and lasts till the shockwave from collision plane reach the boundary of the nuclei. At the later times the system comes to the third stage that corresponds to the expansion process that is finally changes to the last stage when Rayleigh-Plateau instability is observed and the fragmentation takes place due to the Coulomb forces. It is shown that the final topology of the system is fully defined during the first two stages of the collision. Modification of the model is suggested to include the curvature correction to the surface tension coefficient. Modification of the proximity nucleus-nucleus potential is suggested that accounts for the curvature correction to the surface tension coefficient. The effect of the surface curvature on the orientation effects in the fusion reactions of the deformed nuclei is studied. It is shown that in case of the deformed nuclei suggested correction gives a non-negligible contribution to the fusion barriers heights and positions depending on the mutual orientation of the nuclei. Theoretical model of the facilitated diffusion in the membrane systems allowing prediction of the influence of the biological tissues irradiation by heavy ion and proton beams on the diffusive flow is suggested. The changes in the structure and thermodynamic properties of water under the irradiation by the α-particles are studied in the molecular dynamic simulations. To interpret the obtained numerical results the theoretical model based on the fundamental Bogolyubov chain of equations is adapted and the “effective temperature” of the system is calculated.