Induced radiation of an electron in a plane wave in a magnetic field

This paper discusses the induced radiation of electrons in the field of a plane electromagnetic wave propagating along the intensity vector of a uniform magnetic field. Expressions are obtained for the power and frequencies of the radiation. The role of the polarization of the plane wave in the radiation process and the effect of the magnetic field present on the induced radiation in the field of a plane wave are investigated. Several specific cases are discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 49–55, April, 1979.     

On the radiation of fermions in the field of two electromagnetic waves

We consider the radiation of an electron with anomalous magnetic moment in the field of two plane electromagnetic waves of different frequencies but the same direction of propagation. We obtain formulas for the probability amplitude and intensity of photon emission by the electron in the field of these waves. The possibility of photon emission by a neutral fermion in such a field is shown.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 11, pp. 55–60, November, 1972.The authors would like to than Professor V. G. Bagrov for his attention to this work.     

Light propagation in a strong external magnetic field with regard to quantum corrections

Linearized motion equations for electromagnetic wave field in the external magnetic field have been solved for the PVLAS experiment configuration within the low-energy approximation of quantum electrodynamics. It has been shown that the wave propagation velocity depends on the initial direction of the plane of wave polarization. Dispersion laws corresponding to the waves with mutually perpendicular directions of polarization have been established. The dependence of ellipticity of laser radiation field on initial polarization and the value of the external magnetic field has been obtained. The ellipticity parameter for the configuration of the system used in the PVLAS experiment has been found.     

Influence of a constant magnetic field on the radiation of a planar undulator

The influence of a constant magnetic field on the radiation of a planar undulator is studied analytically with the use of generalized Bessel functions. The behavior of on-axis radiation intensity in the undulator and the influence of a magnetic field on off-axis radiation are investigated. The critical magnitude of the constant component of the magnetic field, which has a significant effect on the motion of electrons in the undulator, is calculated analytically. The examples of several planar undulators are discussed, and the influence of the Earth’s magnetic field on their spectrum is evaluated.     

On the theory of the relativistic motion of a charged particle in the field of intense electromagnetic radiation

Averaged relativistic equations of motion of a charged particle in the field of intense electromagnetic radiation have been obtained in the geometrical optics approximation using the Bogoliubov method. Constraints are determined under which these equations are valid. Oscillating additions to the smoothed dynamical variables of the particle have been found; they are reduced to known expressions in the case of the circularly and linearly polarized plane waves. It has been shown that the expressions for the averaged relativistic force in both cases contain new additional small terms weakening its action. The known difference between the expressions for the ponderomotive force in the cases of circularly and linearly polarized waves has been confirmed.     

Motion and radiation of a charge in a plane wave and a magnetic field

The motion and radiation of an electron moving in the field of a plane wave of elliptical polarization and a magnetic field is considered. By the methods of classical and quantum theory, the effect of the plane-wave polarization on the characteristics of the particle motion and radiation is investigated. Some particular cases are considered.Translated from Izvestiya Vysshikh Uchebnykh Zavedeniis Fizika, No. 10, pp. 70–74, October, 1978.     

Nonlinear dynamics of a continuum Heisenberg spin chain with an anisotropy and an external magnetic field

By stereographically projecting the spin vector onto a complex plane in the equations of motion for a continuum Heisenberg spin chain with an anisotropy (an easy plane and an easy axis) and an external magnetic field, the effect of the magnetic field for integrability of the system is discussed. Then, introducing an auxiliary parameter, the Lax equations for Darboux matrices are generated recursively. By choosing the constants, the Jost solutions are satisfied the corresponding Lax equations. The exact soliton solutions are investigated, then the total magnetic momentum and its z-component are obtained. These results show that the solitary waves depend essentially on two velocities which describe a spin configuration deviating from a homogeneous magnetization. The depths and widths of solitary waves vary periodically with time. The center of an inhomogeneity moves with a constant velocity, while the shape of soliton also changes with another velocity and this shape is not symmetrical with respect to the center. The total magnetic momentum and its z-component vary with time.     

Corrections to the Thomson cross section caused by relativistic effects and by the presence of the drift velocity of a classical charged particle in the field of a monochromatic plane wave

An approach to the solution of the relativistic problem of the motion of a classical charged particle in the field of a monochromatic plane wave with an arbitrary polarization (linear, circular, or elliptic) is proposed. It is based on the analysis of the 4-vector equation of motion of the charged particle together with the 4-vector and tensor equations for the components of the electromagnetic field tensor of a monochromatic plane wave. This approach provides analytical expressions for the time-averaged square of the 4-acceleration of the charge, as well as for the averaged values of any quantities periodic in the time of the reference frame. Expressions for the integral power of scattered radiation, which is proportional to the time-averaged square of the 4-acceleration of the charge, and for the integral scattering cross section, which is the ratio of the power of scattered radiation to the intensity of incident radiation, are obtained for an arbitrary inertial reference frame. An expression for the scattering cross section, which coincides with the known results at the circular and linear polarizations of the incident waves and describes the case of elliptic polarization of the incident wave, is obtained for the reference frame where the charged particle is on average at rest. An expression for the scattering cross section including relativistic effects and the nonzero drift velocity of a particle in this system is obtained for the laboratory reference frame, where the initial velocity of the charged particle is zero. In the case of the circular polarization of the incident wave, the scattering cross section in the laboratory frame is equal to the Thompson cross section.     

Boson radiation in a periodic magnetic field

The first correction to the boson radiation intensity is obtained in an arbitrary two-component periodic magnetic field. In the ultrarelativistic case, the quantum correction for a specific kind of potential in which spiral motion is realized will agree with the corresponding expression in the theory of synchrotron radiation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 27–32, September, 1989.The authors are grateful to Prof. V. G. Bagrov for attention to the research.     

On the influence of radiation friction on charge motion in a plane monochromatic wave field

It is shown that radiation friction during charge motion in a plane monochromatic wave results in swinging of the oscillations in a plane perpendicular to the wave propagation direction. An expression is obtained for the characteristic time of motion variation because of radiation losses. It is shown that if the invariant wave intensity parameter is ξ ?137, radiation friction in the classical domain can influence the motion substantially for a wave phase change Δ??2π.     

Electromagnetic properties of the massive dirac neutrino in an external electromagnetic field

An interpretation of the anomalous magnetic moment of the neutrino is given; we derive an effective Hamiltonian which describes the motion of the neutrino in a weak external magnetic field and calculate the radiation intensity due to the anomalous magnetic moment of the neutrino in a constant magnetic field.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 64–70, March, 1988.     

Motion of a classical charged particle with spin in the external field of a plane electromagnetic wave

We obtain the solution to the equations of motion for a classical particle with spin, electric and magnetic charges, and electric and magnetic normal and anomalous moments, in the field of a plane electromagnetic wave. An explicit form of the solution is given for linearly polarized waves and monochromatic circularly polarized waves. The possibility is noted that due to the presence of the moments, the particle can be accelerated to speeds arbitrarily close to the speed of light.Translated from Izvestiya Vysshykh Uchebnykh Zavedenii, Fizika, No. 11, pp. 71–74, November, 1981.     

Impact of a DC magnetic field on evanescent wave intensity amplification for a magnetocompensated antiferromagnet

The impact of a dc magnetic field on evanescent TE and TM waves at the interface of transparent media comprising a semiconductor layer and a semi-infinite antiferromagnet is investigated using Otto geometry as an example. It is shown that switching a dc magnetic field orthogonal to a sagittal plane allows maximum amplification of the intensity of propagating evanescent TM or TE waves in both a layer and in semi-infinite space. The optimum conditions correspond to the formation of a peculiar TM or TE surface wave.     

Electron scattering from an assembly of point scatterers in the presence of a quantizing magnetic field

Summary We have studied the scattering of electrons by a structured target in the presence of a quantizing static magnetic field, under the assumption that the presence of the field does not affect the behaviour of the massive target nuclei, but it influences only the motion of the incident electrons. In this case, the electron motion in the plane perpendicular to the magnetic field is confined within a typical distance given by the cyclotron radius ρ₀=(cℏ/|e|B)^1/2, that for particular values of the intensity of the magnetic field can be comparable with the distance between two scattering centres. The known field-free interference conditions are modified, depending both on the energy of the incident particle and on the intensity and the direction of the magnetic field. The general case of a three-dimensional scattering array has been derived in detail. Numerical results are given for the case of two scattering centres in perpendicular geometry. To speed up publication, the authors of this paper have agreed to not receive the proofs for correction.     

Induced radiation by fermions in the field of two collinear plane electromagnetic waves of arbitrary polarization

In the present article we consider the effect of induced radiation of fermions, moving in the field of two monochromatic plane waves of arbitrary polarization, propagating in one direction. Equations are obtained for the radiation probability and total radiated power of a particle. The spin behavior in this process is investigated.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 12–18, November, 1974.     

Landau levels and electron radiation in planar channeling in monocrystals

The influence of a magnetic field on the motion and radiation of an electron is considered for planar channeling in a monocrystal. It is shown that discrete levels analogous to Landau levels appear in the super-barrier domain of transverse energies instead of a continuous spectrum. The spectral composition and intensity of anomalous and normal waves are computed. The possibilities are discussed of the observation of electron radiation with Landau levels.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 88–93, August, 1989.     

The electron in the quantum field of a plane wave and the classical field of Redmond configuration

The Dirac equation is solved exactly for an electron interacting with both the quantum field of a plane wave and with a classical electromagnetic field, consisting of a plane wave and a constant, homogeneous magnetic field, parallel to the direction of propagation of both waves.     

Effect of a planar magnetic field on the domain wall dynamics in a double-layer uniaxial magnetic film

Motion of an isolated domain wall in a double-layer uniaxial magnetic film, where the film layers differ in characteristic length, saturation magnetization and damping parameter, is investigated by solving the Slonczewski equation. A planar magnetic field is applied normal to the domain-wall plane. The dependences of the threshold field and limiting velocity of disruption of the steady-state motion of the domain wall on the planar magnetic field value are obtained. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 60–63, December, 2008.     

Effect of quantum interference processes on the angular distribution of the spontaneous radiation in the D line of alkali-metal vapors in a laser wave field

The resonance fluorescence of a degenerate V-type three-level atom in the field of an intense monochromatic wave with arbitrary polarization composition is investigated. The equations of motion, the general form of the radiation relaxation operator, and the analytical expressions for the angular distribution of the intensity of the spontaneous radiation from atoms, and the total intensity of the resonance fluorescence for such systems are obtained. The angular distribution of the spontaneous radiation from atoms for the D line of alkali-metal vapors is investigated. It is predicted theoretically that the intensity of the resonance fluorescence will decrease as the intensity of the pump wave increases in observations in a direction of the electric field vector of the laser wave.     

亚波长间距理想导体球阵列近区时间反演电磁场的快速求解

为快速求解亚波长间距分布的理想导体球阵列近区的时间反演电磁场,提出一种基于等效偶极子模型的解析分析方法.首先,通过分析球面波照射理想导体小球的散射场解析解发现,散射场可以近似等效为电磁偶极子辐射场的叠加.等效偶极子的强度与初始激励源的幅度成正比关系.通过建立不同小球等效偶极子矢量间的耦合方程组可以直接求解得到相应矢量的大小.然后,结合时间反演腔理论得到相应的时间反演并矢格林函数,继而得到小球阵列近区的时间反演场分布.最后,通过与数值仿真软件的计算结果进行对比,验证了方法的正确性及高效性.研究表明,时间反演技术结合近场亚波长间距小散射体加载能够实现超分辨率的场聚焦.