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Aleksandrov N.L.,Moscow Institute of Physics and Technology | Kindysheva S.V.,Moscow Institute of Physics and Technology | Kochetov I.V.,Troitsk Institute for Innovation and Fusion Research
Plasma Sources Science and Technology

Kinetic processes in a weakly ionized non-equilibrium plasma are considered under conditions that are typical for plasma-assisted ignition/combustion and flow control. The focus is on the simulation of active species production that leads to ignition delay reduction, flame stabilization and expansion of the flammability limit of combustible mixtures. We discuss the lack of information on electron cross sections for hydrocarbons and the accuracy of widely used approaches to simulate kinetics of active species production in air and combustible mixtures. Fast gas heating after a high-voltage nanosecond discharge is studied for various gas mixtures and reduced electric fields. We analyze the effect of negative ions generated in the afterglow of a high-voltage discharge with regard to plasma-assisted ignition and plasma aerodynamics application. © 2014 IOP Publishing Ltd. Source

Grigorian G.M.,Saint Petersburg State University | Kochetov I.V.,Troitsk Institute for Innovation and Fusion Research
Plasma Physics Reports

The formation of carbonitride (CxNy) films in the active and afterglow phases of a glow discharge in CH4-N2 mixtures (as well in these mixtures diluted with argon and helium) was studied experimentally. The dependences of the film growth rate on the discharge current and gas pressure are obtained. The composition (the N/C ratio) and IR absorption spectra of the films are determined. Measurements of the absorption spectra made it possible to identify bonds between C and N atoms. A novel method of carbonitride film deposition in the "double afterglow" mode was proposed. The use of this method appreciably increases the film deposition rate. Possible mechanisms of the formation and destruction of carbonitride films in the active and afterglow phases of the discharge are discussed. © 2013 Pleiades Publishing, Ltd. Source

Filippov A.V.,Troitsk Institute for Innovation and Fusion Research
Contributions to Plasma Physics

The influence of the outer boundary shape on the electrostatic interaction of two charged point macroparticles in an equilibrium plasma is studied within the Debye-Hückel approximation, i.e., based on the linearized Poisson-Boltzmann model. It is shown that the boundary shape has a strong influence on the electrostatic interaction between two macroparticles, which switches from repulsion at small interparticle distances to attraction as it approaches the half-length of the computational cell. It is found that in the case of dust particles arranged in the nodes of a simple cubic lattice, the electrostatic force acting on them is equal to zero; hence, an infinite simple cubic lattice of charged dust particles is mechanically stable. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim). Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Source

Dyatko N.,Troitsk Institute for Innovation and Fusion Research | Donko Z.,Hungarian Academy of Sciences
Plasma Sources Science and Technology

At low reduced electric fields the electron energy distribution function in heavy noble gases can take two distinct shapes. This 'bistability effect' - in which electron-electron (Coulomb) collisions play an essential role - is analyzed here for Xe with a Boltzmann equation approach and with a first principles particle simulation method. The solution of the Boltzmann equation adopts the usual approximations of (i) searching for the distribution function in the form of two terms ('two-term approximation'), (ii) neglecting the Coulomb part of the collision integral for the anisotropic part of the distribution function, (iii) treating Coulomb collisions as binary events, and (iv) truncating the range of the electron-electron interaction beyond a characteristic distance. The particle-based simulation method avoids these approximations: the many-body interactions within the electron gas with a true (un-truncated) Coulomb potential are described by a molecular dynamics algorithm, while the collisions between electrons and the background gas atoms are treated with Monte Carlo simulation. We find a good general agreement between the results of the two techniques, which confirms, to a certain extent, the approximations used in the solution of the Boltzmann equation. The differences observed between the results are believed to originate from these approximations and from the presence of statistical noise in the particle simulations. © 2015 IOP Publishing Ltd. Source

Samokhin A.A.,Troitsk Institute for Innovation and Fusion Research
Plasma Physics Reports

An efficient numerical code for simulating the propagation of a high-power electromagnetic pulse in a vacuum transmission line is required to study the physical phenomena occurring in such a line, to analyze the operation of present-day megavolt generators at an ̃10-TW power level, and to design such new devices. The main physical theoretical principles are presented, and the stability of flows in the near-threshold region at the boundary of the regime of magnetic self-insulation is investigated based on one-dimensional telegraph equations with electron losses. Numerical (difference) methods-specifically, a method of characteristics and a finite-difference scheme-are described and their properties and effectiveness are compared by analyzing the high-frequency modes. © Pleiades Publishing, Ltd., 2010. Source

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