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Information × Registration Number 0225U005201, (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 особливостей та ефективності розподілу енергії високочастотних хвиль у магнітоактивній плазмі при їх нелінійній взаємодії. Збудження високих номерів гармонік електромагнітних хвиль зарядженими частинками в азимутально-гофрованих електродинамічних структурах. Умови однорідного фокусування послідовності позитронних згустків при збудженні кільватерних полів у плазмі. Теорія збудження кільватерних коливань релятивістськими електронними згустками в напівпровідникових резонаторах. Моделювання процесів, розвиток яких може призводити до переходу позитивної корони в іскру. Head Onishchenko Ivan M., д.ф.-м.н. Registration Date 26-12-2025 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 efficiency of energy distribution of high-frequency waves in magnetoactive plasma during their nonlinear interaction was investigated, taking into account resonant conditions of interaction both in time and space. Through the mechanism of wave-particle interaction, it becomes possible to purposefully transfer energy of external waves to electron and ion components of plasma. An electrodynamic theory of high harmonics excitation of electromagnetic waves by a ring electron beam in coaxial cylindrical waveguide with azimuthally corrugated outer wall placed in axial magnetic field was created. The frequencies and increments of growth under conditions of Cherenkov and cyclotron resonances of beam electrons with harmonics of TE wave were obtained. The theory of wake plasma excitation and eigen electromagnetic oscillations in a semiconductor resonator by relativistic electron bunch was developed. The spatial structure of oscillations and their frequency spectra showed the prospects of using semiconductors in problem of electromagnetic radiation generation and in new methods of high-gradient acceleration. Numerical simulation of wakefield excitation in plasma by a sequence of positron bunches determined that at coincidence of distance between bunches with half-length of excited plasma wave, focusing fields are obtained that are the same for all bunches of sequence. In this case the leading front of bunches is slowed down and the trailing front is accelerated, that leads to a decrease in energy spread of bunches and makes proposed focusing method promising for use in focusing sections of electron-positron colliders. It is shown that in plasma-chemical streamer discharges, secondary streamers are a manifestation of plasma density equalization along the streamer channel after main streamer covers discharge gap. In a streamer mode of positive corona, it is in the secondary streamers that the bulk of oxygen dissociation occurs, the first step towards ozone formation. Product Description popup.authors Kostiantyn V. Galaydych Denys S. Bondar popup.nrat_date 2025-12-26 Close