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Information × Registration Number 0225U002494, (0122U001483) , R & D reports Title Investigation of anomalous diffusion processes in the interaction of high-energy particles with intense external fields and matter popup.stage_title Дифузія швидких заряджених частинок у вигнутих кристалах, перерозподіл частинок по кутам розсіяння при входженні пучків заряджених частинок у кристал та взаємодія ультракоротких банчів електронів з речовиною Head Onyshchenko Hennadii M., Кандидат фізико-математичних наук Registration Date 17-03-2025 Organization V.N. Karazin Kharkiv National University popup.description1 The aim of this work is to study the manifestations of anomalous diffusion and dynamic chaos in the interaction of high-energy particles with intense external fields and matter. The main problems to be solved are the following: - to find the diffusion indices of a beam of fast charged particles in straight and bent crystals; - to find conditions for the development of dynamic chaos in the interaction of a beam of charged particles and excited eigenwaves of the resonator, taking into account not only Cherenkov resonances, but also parametric resonances of higher order in the amplitudes of excited waves; - to study the process of diffusion of relativistic electron beams that generate high-energy electromagnetic radiation, taking into account two important factors: the presence of synchrotron cooling and relatively high strength of the external periodic field, which leads to higher harmonics of radiation; - to determine the conditions of applicability and achievable accuracy when using the diffusion approach when describing the transport of fast neutrons in a heterogeneous multiplicative medium with variable diffusion coefficients; - to obtain the dependences of the magnitude of the ionization losses of the bunch of particles on the time due to the spreading of the bunch, under the conditions of coherent effects in these losses; - to investigate the scenario of the process of redistribution of particles by scattering angles during particle channeling in the crystal. popup.description2  The influence of incoherent scattering of fast charged particles during the motion of a particle beam near one of the crystallographic planes of the crystal on the redistribution of the particle beam along the scattering angles has been studied. It has been shown that during motion in a crystal at angles to the crystallographic plane that exceed the critical angle of planar channeling, the phenomenon of anomalous diffusion occurs.The influence of anomalous diffusion on the propagation of neutrons in a multiplying system has been investigated. The results of numerical calculations of the equations of anomalous diffusion of neutrons indicate that in the case of subdiffusion, which corresponds to the presence of thin absorbing elements in the system, there is an acceleration of the decrease in the neutron flux with time. The study of the regular and chaotic dynamics of particles of a beam that excites high-frequency fields in the range from 1 GHz to 10 GHz in a resonator filled with plasma in a strong external magnetic field has been carried out. It is shown that in such a system local instability of the motion of the beam particles can develop due to the overlap of nonlinear resonances. The process of increasing the width of the energy spectrum of the beam of ultrarelativistic electrons is studied. It is found that the specified process can be generalized to anomalous diffusion, and the type of diffusion changes from ballistic at the beginning of the process to normal. The dependence of the diffusion index of fast charged particles in straight and bent oriented crystals on the energy of the transverse motion of the particles is studied. It is shown that the specified dependence is not monotonic. An analytical description of the ionization energy losses of two ultrarelativistic charged particles moving in a hydrogen medium is constructed, taking into account the interference effects in these losses. A formula is obtained that describes the dependence of these losses o Product Description popup.authors Buliak Yevhen V. Hirka Ihor O. Hakh Andrii H. Demydenko Illia V. Kitsenko Oleksandr Yu. Kyzym Pavlo S. Kyryllin Ihor V. Kovtun Volodymyr Ye. Malovytsia Maksym S. Manuilenko Oleh V. Omelchenko Viktoriia D. Trofymenko Serhii V. Truten Valentyn I. Ulybkin Oleksandr L. Shulha Mykola F. Shchus Oleksandr Р. popup.nrat_date 2025-03-17 Close