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Information × Registration Number 0225U000631, (0121U109590) , R & D reports Title Elaboration of new methods for generating regular and stochastic electromagnetic radiation in beam-plasma systems and high-gradient acceleration of charged particles with fields excited by high-current beams and powerful laser pulses. Simulation of electric discharges of different type for search of effective modes in nonequilibrium plasma chemistry popup.stage_title Дослідження ролі особливих розв’язків в теорії динаміки заряджених частинок. Дослідження процесів релаксації заряджених частинок у зовнішньому постійному магнітному полі. Динаміка кільватерних полів та сценарій розвитку поперечної нестійкості (BBU) релятивістських електронних згустків в плазмово-діелектричних електродинамічних структурах. Одночасне прискорення та фокусування електронних та позитронних згустків у плазмово-діелектричних кільватерних прискорювачах при оптимальному поперечному профілі густини плазми в дрейфовому каналі. Збудження кільватерних електромагнітних полів послідовністю релятивістських електронних згустків в іонно-діелектричних резонаторах. Транспортування іонного пучка, компенсованого радіально інжектованим додатковим електронним пучком в дрейфовому проміжку між двома каспами. Моделювання утворення озону у стримерному режимі позитивної корони. Head Onishchenko Ivan M, д.ф.-м.н. Registration Date 15-01-2025 Organization National Science Center "Kharkiv Institute of Physics and Technology" popup.description1 The purpose of scientific work is theoretical research and development: physical principles of generation, on the basis of which new types of sources of powerful regular and stochastic radiation can be created in undeveloped ranges of wavelengths; the concept of high-gradient acceleration of charged particles, which is based on the excitation of intense wakefields in plasma and dielectric by an electron bunch or a laser pulse; methods of compensation of the spatial charge of the high-current ion beam in the induction accelerator; theoretical bases of streamer discharges for their use in nonequilibrium plasma chemistry. popup.description2  The processes associated with the emergence of special solutions in some physical systems are studied. In such cases, in order to correctly describe the dynamics of the systems, it is necessary to increase the modeling accuracy or use the adaptive methods. Besides, it reveals that such systems can be very sensitive to those small, but not taken into account in the mathematical model, parameters. The theory of relaxation of the longitudinal momentum of a relativistic electron beam moving in periodic magnetic field is constructed, taking into account the effects of radiation friction and diffusion of particles in the field of their own spontaneous emission. The excitation of the wake field by a relativistic electron bunch in a plasma-dielectric accelerating structure is studied. PIC-modeling shows the possibility of simultaneous acceleration and focusing of the accelerated bunch by a wakefield in a rectangular dielectric waveguide with a plasma channel. The process of longitudinal optical phonons excitation by a relativistic electron bunch or their periodic sequence in an ion-dielectric resonator is considered. Two main nonlinear mechanisms that restrict the resonant growth of the wave amplitude are taken into account  the trapping mechanism and the nonlinear frequency shift caused by the anharmonicity of longitudinal phonons. In the problem of inertial heavy-ion fusion, the possibility of using the cusp magnetic field to isolate electrons of a compensated high-current ion beam before acceleration and its compensation by an electron beam after the cusp is investigated. It is shown that the use of a metal plate to collect electrons and avoid the appearance of a polarization field allows, with the considered parameters, to achieve isolation only up to a beam density of 1010 сm-3. Numerical simulation of the streamer mode of positive corona in air and oxygen is performed with calculation of the intensity of oxygen molecule dissociation. Product Description popup.authors Bondar Denys S. Halaidych Kostiantyn V. popup.nrat_date 2025-01-15 Close