Nonstationary Electric Field Research Articles

Gaseous Plasma's Time-behavior on a Plate Motion Damping with Time Influenced by a Non-Uniform Non-Stationary Electric Field.

Gaseous Plasma's Time-behavior on a Plate Motion Damping with Time Influenced by a Non-Uniform Non-Stationary Electric Field.

Time domain analysis of impulse electromagnetic field at the interface of two media

Background. Ultrashort pulses of electromagnetic field are widely used in construction, archeology and demining, etc., by constructing effective georadars of the underlying surface, but theoretical study of physical processes of irradiation of medium is had a limit range of simplified model problems, usually in frequency domain. Therefore, the solutions of the problems of penetration of a pulsed wave with arbitrary time dependence into material medium are of special importance for understanding the possibilities and limitations of georadar’s study. Objectives. To obtain the analytical solution in time domain of the problems of reflection and propagation of a impulse electromagnetic wave through the interface of two media, which is the first model approximation to the description of physical processes that occur during operation of pulsed ultrawideband radar. Materials and methods. The problem of irradiation by nonstationary electric field of a lossless medium with a given permittivity is solved analytically by application of evolutionary approach. It consists in solving of Cauchy’s problem for the second-order partial differential equation Klein–Gordon type with respect to evolutionary coefficients. The components of the electromagnetic field in free space are found by integration by spectral parameters and summation by angular modes with appropriate combinations of basis functions. Results. Cauchy’s problems for differential equations that describe the behavior of reflected and refracted waves are solved. The electrical transverse components of the reflected and refracted waves as a function of time on the longitudinal axis were found for the case of irradiation with the step-like time dependence. Graphs of dependence of electric components on time and coordinates are plotted and analyzed. Conclusion. The phenomenon of an electromagnetic missiles in the medium that was irradiated by a pulsed electromagnetic wave of ultrashort duration was demonstrated for the first time. The obtained results can be generalized for the case of an arbitrary impulse by the Duhamel’s integral method. In addition, the electric field for observation point that do not lie on the longitudinal axis can be considered. An even more interesting continuation of the researches in terms of energy analysis is the study of the behavior of longitudinal electric and transverse magnetic components.

Exact Closed-Form Solutions of the Motion in Non-Inertial Reference Frames, Using the Properties of Lie Groups SO3 and SE3

The paper offers a general symbolic method to study the motion in a non-inertial reference frame. In order to achieve this, we use the algebraic and geometric properties of the Lie group of special orthogonal tensors, SO3, and the Lie group of the rigid body displacements, SE3. We obtain a simplified form of the initial value problem that models the non-inertial motion using a tensor instrument introduced in this paper. Thus, the study of the motion in a non-inertial reference frame is transferred into the study of a classical motion in an inertial reference frame. The applications of this method refer to solving the relative motion problem and deriving the straightforward solution to classical theoretical mechanics problems. The motion in a uniform gravitational force field in a rotating reference frame, the motion of a charged particle in non-stationary electric and magnetic fields, the exact solution of the relative rigid body motion in the non-inertial reference frame are studied. Using this symbolic method in studying the motion in a non-inertial reference frame reduces the number of computations. In addition, it offers, in some essential particular cases, exact closed-form coordinate-free analytical solutions.

Optimization of Non-Stationary Electric Field Parameters in Order to Increase the Efficiency of Chamber Furnaces

Topicality. The presented work is devoted to the urgent task of increasing the energy efficiency of chamber furnaces.The purpose is to solve the problem connected with optimizing the parameters of the non-stationary mode of the applied electric field in order to increase the efficiency of the chamber furnaces. Methodology. According to well-known methods of experiment planning, we obtained a set of Pareto-incomparable solutions of the chamber furnace, taking into account the voltage between the burner and the metal charge, which is the basis of the algorithm. Findings. The work proposes an innovative system acting the process of metal heating in a chamber furnace. The result is a developed chamber furnace control system, in which the optimal values of control actions at each step of the heating cycle are determined according to the created algorithm. The proposed control system is universal, because after miscalculations it produces the dynamics, according to which one needs to change the value of direct-current voltage and gas supply with a step in time to perform any given mode of metal heat treatment. The experimental studies conducted on a real chamber furnace with a bogie hearth at Zaporozhye Titanium and Magnesium Combine confirmed this. The analysis of the obtained metal annealing temperature curve showed that the implementation of the optimal values of the control actions, obtained using the developed algorithm, provides a high uniformity and better quality heating of the metal. The dynamics of gas consumption by the chamber furnace during the heating cycle in the basic mode, without voltage supply, and under the condition of its use in accordance with the performed optimization testify to the possibility of significant energy efficiency improvement of the considered furnaces. Conclusions. For the first time we proved the possibility and efficiency of using a non-stationary electric field in the furnace chamber as a control action, which confirms the originality of the obtained results. The practical value of the research is that the developed control algorithm is universal in terms of metal heat treatment and can be used in chamber furnaces of any industrial enterprise, while one heating cycle reduces the consumption of natural gas by more than 10 %.

Stabilization of a diffusion flame by a non-stationary electric field

The work is devoted to the study of stabilization of a diffusion torch by an electric field with a time-varying field line configuration. The stability of combustion was studied using this method of stabilization of the flame, namely the position of the ignition points in the presence and absence of an electric field. The experiments proved that the stabilizing effect of an electric field with a time-varying field line configuration is observed when the torch is stabilized near and above the plane of the electrodes. When the direction of electric forces coincides with the direction of the fuel jet, the effect of the field will strengthen the fluctuation of flame.

Quantum Solutions in Classical Electrodynamics and Its Connection with Geometrodynamics

A quantum solution of the classical electrodynamics equations has been found. It is shown that all information on the multiparticle process of creation of scalar pairs of particles by a nonstationary self-acting electric field is contained in solutions of the d’Alembert single-particle equation. The existence of a quantum solution of the d’Alembert equation is determined by the Ehrenfest theorem. In this case, the corresponding solution is independent of the Planck constant. The process of conversion of thermal and acceleration energies into radiation has been investigated. It is demonstrated that a self-acting electric field exhibits elastic behavior. The connection of classical electrodynamics with geometrodynamics is established. The geometrodynamic justification of the appearance of the Hubble magnitude in classical electrodynamics is provided. The probabilities of creation of one-dimensional space and charge during tunneling in time of the effective Planck particle are determined. It has been shown that the fine structure constant α can be interpreted as the probability $$ \alpha ={e}^{-\frac{\pi^2\gamma }{2}} $$ of charge creation without charge and real mass. This implies that the so-called fine structure of mathematical constants can contain information on the interactions of matter, which can be used to solve the problem of information loss in black holes.

Free and Forced Oscillations of Charged Particles in the Presence of Inertially Nonstationary Fast Oscillating Quadrupole Electric Fields

Free and forced oscillations of charged particles in the presence of inertially nonstationary quadrupole HF electric fields are studied. Polyharmonic oscillations of charged particles in the presence of fast oscillating fields with slowly varying parameters are represented using a model of a nonstationary harmonic oscillator with the aid of linear relationships of the coefficients of series that serve as solutions to the Mathieu differential equation. The Green function is used to derive expressions for resonance oscillations of charged particles in the presence of nonstationary HF fields with superimposed uniform excitation fields. A particular case of a polyharmonic oscillator with a linearly varying natural oscillation frequency is considered, and expressions for parameters of the excitation function are derived. Analytical expressions are proven by the results of computer simulation.

Electromagnetic Burst Generation during Annihilation of Magnetic Field in Relativistic Laser-Plasma Interaction

We present the results of theoretical studies of formation and evolution of the current sheet in a colliosionless plasma during magnetic reconnection in relativistic limit. Relativistic magnetic reconnection is driven by parallel laser pulses interacting with underdense plasma target. Annihilation of laser created magnetic field of opposite polarity generates strong non-stationary electric field formed in between the region with opposite polarity magnetic field accelerating charged particles within the current sheet. This laser-plasma target configuration is discussed in regard with the laboratory modeling of charged particle acceleration and gamma flash generation in astrophysics. We present the results of 3-dimensional kinetic simulations and theoretical studies on the formation and evolution of the current sheet in a collisionless plasma during magnetic field annihilation in the ultra-relativistic limit. Annihilation of oppositively directed magnetic fields driven by two laser pulses interacting with underdense plasma target is accompanied by an electromagnetic burst generation. The induced strong non-stationary longitudinal electric field accelerates charged particles within the current sheet. Properties of the laser-plasma target configuration are discussed in the context of the laboratory modeling for charged particle acceleration and gamma flash generation in astrophysics.

Penetration of Nonstationary Ionospheric Electric Fields into Lower Atmospheric Layers in the Global Electric Circuit Model

The problem of the penetration of nonstationary ionospheric electric fields into the lower atmospheric layers is considered based on the model of the global electric circuit in the Earth’s atmosphere. For the equation of the electric field potential, a solution that takes into account exponential variation in the electrical conductivity with height has been obtained. Analysis of the solution made it possible to reveal three cases of the dependence of the solution on height. The first case (the case of high frequencies) corresponds to the Coulomb approximation, when the electrical conductivity of the atmosphere can be neglected. In the case of low frequencies (when the frequency of changes in the ionosphere potential is less than the quantity reciprocal to the time of electric relaxation of the atmosphere), a quasi-stationary regime, in which the variation in the electric potential of the atmosphere is determined by the electric conduction currents, occurs. In the third case, due to the increase in the electrical conductivity of the atmosphere, two spherical regions appear: with the Coulomb approximation in the lower region and conduction currents in the upper one. For these three cases, formulas for estimating the electric field strength near the Earth’s surface have been obtained.

Influence of pulse recurrence frequency on the accuracy of electrochemical machining of nickel, copper, and steel

The influence of pulse recurrence frequency on the accuracy of electrochemical machining of steel 08KP, nickel H1, and copper M1 is shown. Variation of the pulse recurrence frequency leads to similar changes in the tool electrode copying accuracy. This allows us to extend the scope of application of the pulsed mode of electrochemical machining. The correlation between the surface passivity and the effects of the pulse mode is demonstrated. A possible explanation of the observed effects using the existing theoretical background regarding the motion of charged particles in nonstationary inhomogeneous electric fields is discussed.

3D model of small-scale density cavern formation in the region of auroral field-aligned currents

A 3D problem of the formation of small-scale density caverns with a nonstationary electric field in the region of auroral electric currents and kinetic Alfven wave currents is considered. It is shown that an excess of the electron current velocity over a certain critical value of their thermal velocity is a probable cause of cavern formation. Linear and nonlinear stages of the density cavern formation are considered, and their main parameters are estimated. In the case of comparatively strong magnetic fields, caverns can be formed with comparable longitudinal and transverse (with respect to the magnetic field) scales. The properties of parameters of small-scale density caverns and nonstationary electric field agree with well-known experimental data.

The Q,G-method in physics of collisionless plasma

An analytic method for analyzing nonstationary processes in collisionless one-dimensional bounded plasma—the Q,G-method—is proposed. Formulas for the distribution function of charged particles escaping from the boundary and moving without collisions in a nonstationary electric field of arbitrary form are obtained. Specific features of the distribution function are revealed and analyzed.

Electrodynamics of Inhomogeneous (Laminated, Angular) Structures

The consistent physic-mathematical model of propagation of an electromagnetic wave in a heterogeneous medium is constructed using the generalized wave equation and the Dirichlet theorem. Twelve conditions at the interfaces of adjacent media are obtained and justified without using a surface charge and surface current in explicit form. The conditions are fulfilled automatically in each section of counting schemes for calculations. A consistent physicomathematical model of interaction of nonstationary electric and thermal fields in a layered medium with allowance or mass transfer is constructed. The model is based on the methods of thermodynamics and on the equations of an electromagnetic field and is formulated without explicit separation of the charge carriers and the charge of an electric double layer. The influence of a slowly moving medium on the electromagnetic wave propagation is considered. The calculation results show the absence of the influence of the medium’s motion on the phase shift of waves, which is consistent with experimental data.

Influence of a nonstationary electric field on an array of weakly interacting carbon nanotubes

The influence of a nonstationary electric field on a system of weakly interacting carbon nanotubes is considered. An equation for the current density is derived, which is a spatial second-order operator-difference equation, where the “grid nodes” coincide with the location of graphene atoms. It is suggested that the difference operator be replaced by a Laplacian in the two-dimensional case. The results allow us to consider the effect of the generation of millimeter radiation.

Dielectric fluid in inhomogeneous pulsed electric field

We consider the dynamics of a compressible fluid under the influence of electrostrictive ponderomotive forces in strong inhomogeneous nonstationary electric fields. It is shown that if the fronts of the voltage rise at a sharp, needlelike electrode are rather steep (less than or about nanoseconds), the region of negative pressure arises, which can reach values at which the fluid loses its continuity with the formation of cavitation ruptures. If the voltage on the electrode is not large enough or the front is flatter, the cavitation in the liquid does not occur. However, a sudden shutdown of the field results in a reverse flow of liquid from the electrode, which leads to appearance of negative pressure, and, possibly, cavitation.

Electron-optical metrology with femtosecond time resolution (theory and experiment)

The principles of simultaneous spatial and temporal focusing of photoelectron beams in nonstationary electric fields are theoretically studied and experimentally realised as applied to time-analysing image-converter tubes (ICTs). It is theoretically shown that the use of nonstationary focusing electric fields makes it possible to surpass the theoretical time resolution limit of ICTs determined for stationary fields by Zavoisky and Fanchenko in the 40s – 50s of the last century. The possibility of forming electron packets with an energy of and a subfemtosecond duration (below ) gives impetus to the development of time-resolved electron diffraction, which is a direct method of investigation of atomic-molecular dynamics in solid and gaseous media.

Influence of nonstationary electric field on carbon nanotubes

We consider how a nonstationary electric field influences a system of nanotubes. Based on the results, the effect of generation of millimeter radiation is predicted. The mathematical simulation results are presented.

Effect of a nonstationary electric field with different front profiles on carbon nanotubes

Generation of millimeter radiation in a medium based on nanotubes at different profiles of the nonstationary electric field’s front is theoretically studied and mathematically simulated. The radiation gain is based on damped periodic oscillations of the surface current in nanotubes due to kinetic inductance and quantum capacitance in a nonstationary electric field.

Generation of electromagnetic radiation based on nanotubes under a constant electric field and an electromagnetic wave field

The possible generation of radiation in the millimeter range based on nanotubes by an alternating (rapidly oscillating) electric field under a constant (or nonstationary) electric field is studied. Radiation enhancement is based on a periodic dependence of the current in nanotubes in such electric fields. The results of a mathematical simulation are presented.

Formation of density cavities with a nonstationary electric field in the zone of auroral field-aligned currents

The formation of small-scale density cavities with a nonstationary electric field, which are registered in the Earth’s auroral magnetosphere, has been analyzed. It has been indicated that cavities are probably initially caused by quasi-static field-aligned electric currents and currents of kinetic Alfven waves exceeding threshold values. Urgent variants of the linear and nonlinear stages of density disturbance instabilities have been considered. The determined properties of the parameters of small-scale density cavities and nonstationary electric fields are in agreement with the known experimental data.