Search academic texts

Information × Registration Number 0225U002236, (0123U101803) , R & D reports Title Transport processes and kinetics of low-temperature and fusion plasmas popup.stage_title Моделі для опису процесів перенесення в дугових розрядах та моделі на базі дрейфово-кінетичних рівнянь для опису впливу процесів перенесення на поширення хвиль в термоядерній плазмі токамаків Head Denysenko Ihor B., Доктор фізико-математичних наук Registration Date 25-02-2025 Organization V.N. Karazin Kharkiv National University popup.description1 The aim of this project is to develop a theory and a methodology for description of transport processes in low-temperature and fusion plasmas using kinetic approaches. To achieve this aim, it is planned to solve the following tasks: to develop an arc discharge model for the convective mode of evaporation of a metal anode; to study how the speed of vapor expansion in the near-anode layer depends on the temperature of anode and the current flowing through the discharge, as well as to investigate the properties of the arc discharge under these conditions; to describe the processes in the near-anode layer using phenomenological approaches, as well as using the Boltzmann kinetic equation; to develop theoretical and numerical models describing motion of nanoparticles in an afterglow plasma with taking into account that the charging of nanoparticles is a stochastic process, and using these models to investigate how the motion and deposition of nanoparticles on surfaces depend on external conditions; to study the conditions of formation of low-energy ion beams with a high current density in the plasma created by a source based on an arc discharge with a thermocathode; to determine the conditions for the formation of a double layer of volume charge around the plasma created in the vapors of the anode material; to investigate the conditions for the formation of H– ions near the metal hydride cathode and to develop methods for their effective extraction; to obtain the dispersion characteristics of low-frequency waves in 2D tokamaks taking into account the toroidal magnetic drift of both untrapped and trapped plasma particles, their finite Larmor radius and the finite width of their banana trajectories. A revision of the Braginsky standard transport model is planned to include the electron relativity and to find relativistic corrections to the transport coefficients. A relativistic generalization of the neoclassical transport theory for toroidal systems is also planned. popup.description2  Physical and numerical models of arc discharge in the convective mode of evaporation of metal anode are developed. A system of differential equations describing the spatial distributions of concentrations and temperatures of discharge particles in the near-anode quasi-neutral region of the arc discharge and boundary conditions for solving these equations are proposed. For the case where the anode is copper, expressions for various reaction and transfer coefficients and reaction cross sections are obtained as functions of the electron and ion temperatures and the ion and atom concentrations. A global model describing the ionization region of a magnetron discharge in argon with a copper target is developed. Experimental studies of the near-surface formation of low-energy ion and electron beams in the plasma of an arc discharge with a thermionic cathode were carried out. New methods of controlling the current and energy of ions in this discharge are proposed. The dependences of the ion current density on the working pressure in the vacuum chamber and the position of the holder relative to the axis of the plasma source are determined. The possibility of increasing the ion current density on the sample surface by using a permanent ring magnet is shown. The surface of the (TiZr/TiSi)N sample was treated with a plasma ion flux. It is shown that such treatment leads to the cleaning of the surface layer from various impurities without damage and creates a substrate for subsequent thermionic deposition of a coating with a high degree of adhesion. A model based on self-consistent drift-kinetic equations and wave equations is developed to study the dispersion characteristics of low-frequency waves in 2D axially symmetric tokamaks, taking into account the stationary current, transport processes, toroidal magnetic drift of plasma particles, their finite Larmor radius, and the finite width of their banana trajectories Product Description popup.authors Ivko Serhii V Azarenkov Mykola O. Bondar Denys S. Volkova Yuliia Ye. Harkusha Ihor Ye. Hrechko Yaroslav O Kanishсheva Mariia M. Nosova Olena M. popup.nrat_date 2025-02-25 Close