Acceleration of charged particles and radiation-reaction in strong plane and spherical waves

A comparison between the acceleration of charged particles in plane and spherical waves including the effect of radiation reaction is given. In strong electromagnetic waves the charged particle stays initially at practically constant phase — “phase locked” part of the motion — and only after it has travelled many wavelengths does the wave overtake the particle. During the phase-locked part of the motion depending upon the initial conditions of how a particle is injected into the wave radiation reaction can lead to both a net energy gain or loss compared to the motion without radiation reaction. In a plane wave however radiation reaction always leads to a net energy gain if it can build up long enough. A test of this latter prediction by means of ultra-strong lasers might be possible.     

Acceleration of charged particles and radiation reaction III: Motion in pulsar vacuum fields

We derive an analytic solution for particle motion in strong, linearily polarized spherical waves for the case of negligible radiation reaction. If radiation reaction is included the initial part of the motion can also be described analytically, whereas the further motion is obtained from a numerical integration of the equation of motion.     

Induced radiation by charged particles moving in a plane electromagnetic wave

It is shown that when a charged particle moving in the field of a plane electromagnetic wave is subjected to another electromagnetic wave, incident at some angle with respect to the first, induced radiation and absorption occur. Under certain conditions the induced radiation predominates over the absorption.Translated from Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 50–53, September, 1969.The authors thank professor I. M. Ternov for useful discussions.     

Calculation of the acoustic radiation force on coated spherical shells in progressive and standing plane waves

In this paper, analytical equations are derived for the time-averaged radiation force induced by progressive and standing acoustic waves incident on elastic spherical shells covered with a layer of viscoelastic and sound-absorbing material. The fluid surrounding the shells is considered compressible and nonviscous. The incident field is assumed to be moderate so that the scattered field from the shells is taken to linear approximation. The analytical results are illustrated by means of a numerical example in which the radiation force function curves are displayed, with particular emphasis on the coating thickness and the content of the hollow region of the shells. The fluid-loading on the radiation force function curves is analysed as well. This study attempts to generalize the various treatments of radiation force due to both progressive and standing waves on spherically-shaped structures immersed in ideal fluids. The results show that various ways can be effectively used for damping resonance peaks, such as by changing the fluid in the interior hollow region of the shells or by changing the coating thickness.     

Trapping of charged particles by transverse electromagnetic waves

An estimate is made of the maximum number of resonant particles interacting with a transverse plane electromagnetic wave. This estimate is based on the distribution function, in terms of integrals characterizing the motion of particles in a wave. The values found here for proton fluxes accelerated by an amplitude-modulated wave in the solar corona agree with those measured during sporadic radioemission bursts.     

Dynamics of a beam of charged particles. II

A perturbational method for calculating the effect of the electromagnetic field generated by particles on their motion is proposed. The expansion of a uniformly dense cylindrical beam of relativistic charged particles due to their own field is considered.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii. Fizika, No. 11, pp. 42–44, November, 1992.     

Diffusion of charged particles in strong large-scale random and regular magnetic fields

The nonlinear collision integral for the Green’s function averaged over a random magnetic field is transformed using an iteration procedure taking account of the strong random scattering of particles on the correlation length of the random magnetic field. Under this transformation the regular magnetic field is assumed to be uniform at distances of the order of the correlation length. The single-particle Green’s functions of the scattered particles in the presence of a regular magnetic field are investigated. The transport coefficients are calculated taking account of the broadening of the cyclotron and Cherenkov resonances as a result of strong random scattering. The mean-free path lengths parallel and perpendicular to the regular magnetic field are found for a power-law spectrum of the random field. The analytical results obtained are compared with the experimental data on the transport ranges of solar and galactic cosmic rays in the interplanetary magnetic field. As a result, the conditions for the propagation of cosmic rays in the interplanetary space and a more accurate idea of the structure of the interplanetary magnetic field are determined.     

Electromagnetic plane waves with negative phase velocity in charged black strings

We investigate the propagation regions of electromagnetic plane waves with negative phase velocity in the ergosphere of static charged black strings. For such a propagation, some conditions for negative phase velocity are established that depend on the metric components and the choice of the octant. We conclude that these conditions remain unaffected by the negative values of the cosmological constant.     

Dynamics of charged particles in the field of a spherical magnetic dipole

The results of numerical simulation of the dynamics of charged particles in the field of a spherical magnetic dipole are reported. Interesting features revealed in this dynamics can be used in analysis of near-Earth space with the help of charged particle beams.     

Complication of the spectrum of electromagnetic waves scattered by charged nanoparticles with allowance for radiation reaction

Peculiarities of the scattering of electromagnetic waves by charged nanoparticles have been revealed, given the proper expression for the radiation reaction force. These peculiarities (the change in maximum intensity, the appearance of additional peaks in the spectrum, and others) can be used, in particular, in near-Earth plasma physics and charged nanoparticle physics.     

Acceleration of dust particles by low-frequency Alfvén waves

We investigate the efficiency of acceleration of charged dust particles by low-frequency Alfvén waves in nonlinear approximation. We show that the longitudinal acceleration of dust particles is proportional to the square of the soliton amplitude O(²|bm|), while the transversal acceleration is of O(|bm|). In the conditions of the interstellar medium the resulting velocity of dust particles can reach 0.3 to 1 km s⁻¹.     

Channeling and electromagnetic radiation of relativistic charged particles in metal-organic frameworks

We have developed the theory of electromagnetic interaction of relativistic charged particles with metal-organic frameworks (MOFs). The electrostatic potential and electron number density distribution in MOFs were calculated using the most accurate data for the atomic form factors. Peculiarities of axial channeling of fast charged particles and various types of electromagnetic radiation from relativistic particles has been discussed.     

Propagation of waves in a multicomponent plasma having charged dust particles

Propagation of both low and high frequency waves in a plasma consisting of electrons, ions, positrons and charged dust particles have been theoretically studied. The characteristics of dust acoustic wave propagating through the plasma has been analysed and the dispersion relation deduced is a generalization of that obtained by previous authors. It is found that nonlinear localization of high frequency electromagnetic field in such a plasma generates magnetic field. This magnetic field is seen to depend on the temperatures of electrons and positrons and also on their equilibrium density ratio. It is suggested that the present model would be applicable to find the magnetic field generation in space plasma.     

Intensity of radiation of charged particles passing through crystals

We have calculated the intensity of radiation of a relativistic charged particle moving in a crystalline medium, taking into account the interaction of the charge with the crystal as well as with the radiation. Various modifications to the usual Cerenkov radiation are discussed and under certain conditions enhancement occurs.