Motion Of Charged Particles Research Articles

Directional motion of charged particles near filter membrane

Membrane has many applications in the fields of filtration and separation, but due to the attraction or repulsion exerted by the membrane, the particles will experience a directional motion. As a result, two totally opposite effects, i.e. particle enrichment and exclusion zone, take place in the vicinity of the membrane, and the underlying reason is still not clear. In this work, colloidal particles with negative surface charge are used as a model substance, with the advantages of monitoring the particle concentration in a real time and <i>in situ</i> way, to investigate the influence of cellulose membrane on the movement of particles. The experimental results show that the particles are enriched in the vicinity of the membrane. The diffusiophoresis effect originating from tiny number of ions released by the film is the main reason of the directional movement of the charged particles. Based on the two mechanisms of diffusiophoresis and diffusion, we construct a model and make relevant numerical calculation, and the numerical results are qualitatively consistent with the experimental results. Moreover, in addition to the longitudinal motion of the particles towards the filter membrane, diffusio-osmotic flow and particles lateral diffusion also result in the migration of particles towards the container wall, and further increasing the particle number near the wall.

Motion and Radiation for Charged Particles Revolving Round Centre of Force of Attraction

Nuclear and non-nuclear models of hydrogen atom are proposed, each with N equal to 42 or 43 orbits of revolution. Aberration of electric field is invoked to describe radiation from nuclear model with particle of electronic charge -e and mass nm of electronic mass m, revolving in nth orbit, with angular momentum nL, at radius nr1 from a nucleus of charge +Ne and mass (Nm/2)(1 + N), where n = 1, 2, 3...N, and r1 is radius of first orbit. The revolving particles have total charge -Ne and same total mass as the nucleus. The non-nuclear model has two particles of same mass nm and charges +e and -e, revolving diametrically in nth orbit, at radius nr1 from a centre, with particles of total mass Nm(1 + N). Distinct masses nm gives discrete coplanar circular orbits. A particle dislodged from a circular orbit, revolves in an elliptic path with emission of radiation, at the frequency of revolution, in fine structure, before reverting to a stable circular orbit. The nuclear atom is identified with solid or liquid state of hydrogen and non-nuclear atom with gaseous state

A guiding center implementation for relativistic particle dynamics in the PLUTO code

We present a numerical implementation of the guiding center approximation to describe the relativistic motion of charged test particles in the PLUTO code for astrophysical plasma dynamics. The guiding center approximation (GCA) removes the time step constraint due to particle gyration around magnetic field lines by following the particle center of motion rather than its full trajectory. The gyration can be detached from the guiding center motion if electromagnetic fields vary sufficiently slow compared to the particle gyration radius and period. Our implementation employs a variable step-size linear multistep method, more efficient when compared to traditional one-step Runge Kutta schemes. A number of numerical benchmarks is presented in order to assess the validity of our implementation.

Temporal evolution and rigidity dependence of the solar modulation lag of Galactic cosmic rays

When traveling in the heliosphere, Galactic cosmic rays (GCRs) are subjected to the solar modulation effect, a quasiperiodical change of their intensity caused by the 11-year cycle of solar activity. Here we investigate the association of solar activity and cosmic radiation over five solar cycles, from 1965 to 2020, using a collection of multichannel data from neutron monitors, space missions, and solar observatories. In particular, we focus on the time lag between the monthly sunspot number and the GCR flux variations. We show that the modulation lag is subjected to a 22-year periodical variation, ranging from about 2 to 14 months and following the polarity cycle of the Sun's magnetic field. We also show that the lag is remarkably decreasing with increasing energy of the GCR particles. These results reflect the interplay of basic physics phenomena that cause the GCR modulation effect: the drift motion of charged particles in the interplanetary magnetic field, the latitudinal dependence of the solar wind, the energy dependence of their residence time in the heliosphere. Based on this interpretation, we end up with a global effective formula for the modulation lag and testable predictions for the flux evolution of cosmic particles and antiparticles over the solar cycle.

Dynamics of test particles around charged black holes in Einstein-Æther gravity

This paper focuses on the issues of motion of various kinds of charged, magnetized, and neutral test particles in the vicinity of static and spherically symmetric electrically charged black holes in the Einstein-Æther gravitational theory. Our purpose here is to analyze the effects of the free parameters occurring in the Einstein-Æther theory for particle motion in curved spacetime. Specifically, we have studied the stability of circular and radially varying orbits of different kinds of particles by varying the free parameters [Formula: see text] and [Formula: see text], and also varying the particle’s specific energy, specific angular momentum, and electric charge of the black hole. As a special case, we investigate the charged particle motion around the black holes with a uniform magnetic field by checking the characteristics of the particle’s innermost stable circular orbit. Finally, we propose few values of the parameters [Formula: see text] and [Formula: see text] which mimic the behavior of spin of a Kerr black hole to model an astrophysical black hole.

Charged particle motion in spherically symmetric distributions of magnetic monopoles

The classical equations of motion of a charged particle in a spherically symmetric distribution of magnetic monopoles can be transformed into a system of linear equations, thereby providing a type of integrability. In the case of a single monopole, the solution was given long ago by Poincaré. In the case of a uniform distribution of monopoles, the solution can be expressed in terms of parabolic cylinder functions (essentially the eigenfunctions of an inverted harmonic oscillator). This solution is relevant to recent studies of nonassociative star products, symplectic lifts of twisted Poisson structures, and fluids and plasmas of electric and magnetic charges.

Energizing charged particles by an orbit instability in a slowly rotating magnetic field.

The stability of charged particle motion in a uniform magnetic field with an added spatially uniform transverse rotating magnetic field (RMF) is studied analytically. It is found that the stability diagram of a single particle's orbit depends critically on the chosen boundary conditions. We show that for many boundary conditions and wide regions in the parameter space, RMFs oscillating far below the cyclotron frequency can cause linear instabilities in the motion which break μ invariance and energize particles. Such energization may appear at odds with the adiabatic invariance of μ; however, adiabatic invariance is an asymptotic result and does not preclude such heating by magnetic fields oscillating at slow frequencies. This mechanism may contribute to heating in the edge plasma of field-reversed configurations (FRCs) in rotamak-FRC experiments. Furthermore, these RMF-driven instabilities may significantly enhance azimuthal current drive during the formation of FRCs in such devices.

Magnetized and Magnetically Charged Particles Motion around Regular Bardeen Black Hole in 4D Einstein Gauss–Bonnet Gravity

In this paper, we study the horizon properties and scalar invariants of the spacetime around a regular black hole (BH) in 4D Einstein Gauss-Bonnet (4D EGB) gravity. It is observed that the presence of both Gauss-Bonnet (GB) coupling and magnetic charge parameters causes the shrinking of the outer horizon. We find that the range of the GB parameter α/M2∈(−0.15869,1), and the extreme value of magnetic charge reaches up to gextr=0.886M, which allows for the existence of a BH horizon, while it is gextr=0.7698M for pure Bardeen BH. We also investigate the dynamics of magnetized particles around the magnetically charged Bardeen BH, assuming the particle’s motion occurs in the equatorial plane in the proper observation frame, and the direction of the magnetic dipole moment of the particles is always kept radially and its magnitude is constant. Moreover, the dynamics of magnetically charged particles are also studied, and it is shown that both the energy and angular momentum of the particles corresponding to circular orbits increases with the increase of their magnetic charge. Finally, we also study collisions of magnetized, electrically neutral, and magnetically charged particles around the Bardeen BHs, where we provide analyses of critical angular momentum that may allow collision of the particles near-horizon radius, producing enormous values of center of mass energy of the collisions.

A new integrator for relativistic E-cross-B motion of charged particles

A new explicit numerical scheme for integrating the relativistic equations of motion for electrically charged particles is proposed as an alternative to the Boris integrator. It has been known that the original Boris integrator includes a large numerical error in the relativistic motion, although the integrator has been used in particle-in-cell simulations of plasma for a half century. The present integrator approximates the theoretical trajectory of the relativistic E-cross-B motion for a charged particle more accurately than the previous explicit integrators such as the Boris, Vay, and Higuera-Cary ones.

Charged particle motion and radiation in strong electromagnetic fields

The dynamics of charged particles in electromagnetic fields is an essential component of understanding the most extreme environments in our Universe. In electromagnetic fields of sufficient magnitude, radiation emission dominates the particle motion and effects of nonlinear quantum electrodynamics (QED) are crucial, which triggers electron-positron pair cascades and counterintuitive particle-trapping phenomena. As a result of recent progress in laser technology, high-power lasers provide a platform to create and probe such fields in the laboratory. With new large-scale laser facilities on the horizon and the prospect of investigating these hitherto unexplored regimes, we review the basic physical processes of radiation reaction and QED in strong fields, how they are treated theoretically and in simulation, the new collective dynamics they unlock, recent experimental progress and plans, as well as possible applications for high-flux particle and radiation sources.

Continuous Approach in the Theory of Interaction of Charged Particles with Solids

In this paper, the main radiative processes, for the first time, are considered within the framework of continuum physics, where the motion of charged particles occurs in a continuous resisting medium.Within the analysis, new characteristics of the interaction of ions with matter are introduced. The proposed formalism also uses some results of modern corpuscular theory. It allows giving a physically clear space-time description of the processes and phenomena analyzed in this paper. Further in this paper, the authors have estimated, with a high degree of accuracy, the ranges of ions in various materials; constructed their energy loss profiles; determined the mean free path and mean free time of the charged particles in matter, and proposed the formalism for analyzing the radiative change in the physical properties of solids. For the first time, the physical nature of the main characteristic of the radiation resistance of materials, i.e., the threshold displacement energy, has been studied in detail, and the formula for its calculation has been derived by the authors.

Motion of charged particles in spacetimes with magnetic fields of spherical and hyperbolic symmetry

The motion of charged particles in spacetimes containing a submanifold of constant positive or negative curvature is considered, with the electromagnetic tensor proportional to the volume two-form form of the submanifold. In the positive curvature case, this describes spherically symmetric spacetimes with a magnetic monopole, while in the negative curvature case, it is a hyperbolic spacetime with magnetic field uniform along hyperbolic surfaces. Constants of motion are found by considering Poisson brackets defined on a phase space with gauge-covariant momenta. In the spherically-symmetric case, we find a correspondence between the trajectories on the Poincar\'{e} cone with equatorial geodesics in a conical defect spacetime. In the hyperbolic case, the analogue of the Poincar\'{e} cone is defined as a surface in an auxiliary Minkowski spacetime. Explicit examples are solved for the Minkowski, $\mathrm{AdS}_4\times S^2$, and the hyperbolic AdS-Reissner--Nordstr\"{o}m spacetimes.

Kiselev solution in power-Maxwell electrodynamics

In this work we reconsider the solution describing black holes surrounded by a quintessencelike fluid. This geometry was introduced by Kiselev in 2003 and its physical source was originally modeled by an anisotropic fluid. We show that the Kiselev geometry is actually an exact solution of the Einstein equations coupled to nonlinear electrodynamics. More specifically, we show that the Kiselev geometry becomes an exact solution in the context of power-Maxwell electrodynamics, using either an electric ansatz or a magnetic one. In both cases the physical source can be modeled by a power-Maxwell Lagrangian, albeit with different powers corresponding to the electric or the magnetic charges. We briefly investigate the motion of charged particles in this geometry. Finally, we give the proper interpretation of the black-hole thermodynamics in this context. Similarly to the Schwarzschild-de Sitter case, we note the presence of the Schottky peaks in the heat capacity, signaling out the possibility of this thermodynamic black hole system to function as a continuous heat machine.

Effects of a quadrupolar magnetic term in a generalized Störmer problem on dust grains

A new generalized Störmer problem is proposed.The charged particles motion around a rotating axisymmetric magnetic planet is studied using various conditions mainly in planetary magnetospheres.It is shown that the existence of specific trajectories is due to the quadrupolar and dipolar magnetic terms. Moreover, the equilibrium and stability behaviors and the corresponding orbital frequencies for various kinds of charged dust grains are treated giving rise to a new model describing the dynamical system and leading to more interesting results.

Evolution and composition of flow structures generated by nanosecond pulsed surface arc discharge in a magnetic field

The complete flow structure and the composition of the flow structure generated by Pulsed Surface Arc Discharge in a Magnetic Field (M-PSAD) are the keys to explaining the plasma application mechanism. The experimental results show that the M-PSAD can produce plasma clusters and detonation waves. The thermal motion of charged particles in the plasma cluster is the main reason for the thermal effect of arc discharge. The detonation wave consists of the shock wave, Taylor expansion wave, and two different thickness zones of charged particles. The experimental results provide a profound physical mechanism for applying plasma.

General formulation of Coulomb explosion dynamics of highly symmetric charge distributions

We present a theoretical approach to study the dynamics of spherical, cylindrical and ellipsoidal charge distributions under their self-Coulomb field and a stochastic force due to collisions and random motions of charged particles. The approach is based on finding the current density of the charge distribution from the charge-current continuity equation and determining the drift velocities of the particles. The latter can be used either to derive the Lagrangian of the system, or to write Newton’s equation of motion with the Lorentz force. We develop a kinetic theory to include the stochastic force due to random motions of electrons in our model. To demonstrate the efficacy of our method, we apply it to various charge distributions and compare our results to N-body simulations. We show that our method reproduces the well-known emittance term in the envelope equation of uniform spherical and cylindrical charge distributions with correct coefficients. We use our model for the gravitational collapse of an ideal gas as well as the cyclotron dynamics of a cylindrical charge distribution in a uniform magnetic field and propose a method to measure the emittance of electron beams.

Motion of the charged test particle in the spinning nonlinear electromagnetic black hole

In this paper the motion of charged and uncharged test particles in the rotating nonlinearly charged black hole (BH) is examined. Its asymptotics can be de Sitter or anti--de Sitter, depending on the value of the nonlinear parameter; consequently this BH can present one, two or three horizons, the third one being the cosmological horizon in the de Sitter case. Angular and radial test particle motions are analyzed and compared with its linear electromagnetic counterpart, the Kerr-Newman black hole (KN-BH). Several differences arise with the KN-BH, namely, the equatorial asymmetry is enhanced by the nonlinear electrodynamics field and for charged particles the access to one of the poles is forbidden; besides, a second circular orbit in the neighborhood of the external horizon appears, and the presence of the nonlinear electromagnetic field increases the curvature producing bounded orbits closer to the horizon.

Confined Penrose process and black-hole bomb

We consider the decay of a particle with some energy $E_{0}>0$ inside the ergosphere of a black hole. After the first decay one of particles with the energy $E_{1}<0$ falls towards a black hole while the second one with $% E_{2}>E_{0}\,\ $moves in the outward direction. It bounces back from a reflecting shell and, afterwards, the process repeats. For radial motion of charged particles in the Reissner-Nordst\"{o}m metric, the result depends strongly on a concrete scenario. In particular, an indefinitely large growth of energy inside a shell is possible that gives rise to a black-hole bomb. We also consider a similar multiple process with neutral particles in the background of a rotating axially symmetric stationary black hole. We demonstrate that, if particle decay occurs in the turning point, a black-hole bomb in this case is impossible at all. For a generic point inside the ergoregion, there is a condition for a black-hole bomb to exist. It relates the ratio of masses before and after decay and the velocity of a fragment in the center of mass frame.

Brownian motion of charged particle in oblique electric and magnetic fields with frictional anisotropy

The Brownian motion of charged particles in oblique electric and magnetic fields with frictional anisotropy is studied for the first time using the white noise functional approach. We obtain the following exact expressions: velocity-space and configuration-space probability density functions, mean square deviations for velocity and displacement, and diffusion coefficients. We investigate the effect of the frictional interaction parameters, Γx (or Γy), on the trajectory of the mean position, and the diffusion coefficients along the x- and y-directions for different values of electric and magnetic field strength.

Knowledge Analysis of Charged Particle Motion in Uniform Electromagnetic Field Based on Maxwell Equation

Abstract We study the motion states of charged particles in a homogeneous electromagnetic field based on the Maxwell equations. The authors propose the charged particle properties analysis based on the Maxwell equation and electromagnetic field, first explain the Maxwell equation and electromagnetic field properties analysis, and then analyze the charged particles in the composite field (electric and magnetic field coexistence). List the important knowledge points about the motion of charged particles in an electric field, and determine the center of the circle where the charged particles move in a circular motion, simulate the motion of charged particles in a uniform orthogonal electromagnetic field, if at, the trajectory of the charged particle is a short-amplitude cycloid, if, the trajectory of the charged particle is a long cycloid, if. The realization of simulation is mainly based on theory to obtain phenomena, although it has extensive practical significance for confirmatory experiments, when inspiring and guiding students to carry out inquiry learning, physics teachers should still organically combine simulation experiments with traditional experimental teaching, teacher explanations, and student experiments in teaching design and teaching implementation, in order to cultivate students' independent inquiry ability and experimental innovation ability.