相对论性带电粒子束在轴对称电场和磁场中的温度和能量展宽

从单粒子的相对论性运动方程出发,首先解出运动常数,然后用这些运动常数构成符合Vlasov方程的束粒子分布函数,再由该分布函数算出轴对称电场和磁场中相对论性带电粒子束的束温度和能量展宽,并且对弱相对论性情况和强相对论性情况作了讨论。 关键词：     

Nonlinear Compton scattering of strong laser radiation on channeled particles in a crystal

A version for intense γ-ray radiation based on the multiphoton scattering of strong laser radiation on relativistic particle beam channeled in a crystal is proposed. The incident laser beam and charged particles beam are counter-propagating and the laser radiation is resonant to the energy levels of transversal motion of channeled particles.     

Kinetic equation for a relativistic electron beam propagating along an external magnetic field in dense and rare gas-plasma media

A kinetic equation that describes the transverse dynamics of an axisymmetric paraxial relativistic electron beam propagating along an external magnetic field in a gas-plasma medium is derived with allowance for the influence of the self-consistent electromagnetic field on the beam, the effects related to the nonlaminar motion and rotation of the beam electrons at the exit from the injector, and the scattering and energy loss of the beam electrons in their collisions with the neutral particles of the background gas.     

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.     

Relativistic electron motion in FEL-like fields taking retarded interactions into account

Summary The interaction of two charged particles both with each other (via Lienard-Wiechert retarded potentials) and with the wiggler field of an FEL structure, along which they are launched, is computed by means of the numerical integration of the relativistic motion equations, taking also an incoming laser wave into account. The bunching effect characterizing the collective behaviour of an electron beam in FEL-like fields is simulated by assuming one of the particles to be a suitable macrocharge.     

Effect of coherent synchrotron oscillations on the spectrum of microwave radiation of electrons in storage ring

The paper studies the characteristics of the microwave radiation of relativistic electrons in a storage ring given coherent synchrotron oscillations of the particles in the beam. Within the frame work of the collective phase motion model constructed, it is shown that the band of the generated harmonics is broadened considerably and the power of the coherent losses exceeds the analogous characteristics of the radiation of a beam of particles moving independently.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 17–19, May, 1978.     

Relativistic ponderomotive forces in the field of intense laser radiation

The motion of a relativistic charged particle in the presence of the field of high-power laser radiation represented in the form of a Gaussian beam of arbitrary mode is analyzed. The vector potential of the radiation field is expanded in terms of a small parameter (the ratio of the wavelength to the Gaussian beam waist). A specific feature of averaging with respect to the phases of the high-mode Gaussian beams is demonstrated. The averaged equations for the motion of particle and a general expression for the ponderomotive relativistic force for the circularly polarized radiation are derived. It is demonstrated that relativistic effects suppress the averaged action of high-power laser radiation on the particle.     

Quantum mechanics as relativistic statistics. I: The two-particle case

It is shown that non-relativistic quantum mechanics can be treated as a kind of relativistic statistical theory, which describes the indeterministic motion of classical particles. The theory is relativistic in the sense that the relativistic notion of the state and two-time equations of motion are used. The principles and relations of quantum mechanics are obtained from the principles of statistics and those of classical mechanics.     

Particle beams guided by electromagnetic vortices: new solutions of the Lorentz, Schrödinger, Klein-Gordon, and Dirac equations

It is shown that electromagnetic vortices can act as beam guides for charged particles. The confinement in the transverse directions is due to the rotation of the electric and magnetic fields around the vortex line. A large class of exact solutions describing various types of relativistic beams formed by an electromagnetic wave with a simple vortex line is found both in the classical and in the quantum case. In the second case, the motion in the transverse direction is fully quantized. Particle trajectories trapped by a vortex are very similar to those in a helical undulator.     

Thermal effects in the dissipative instability of the electron beam-plasma systems

The effects of the thermal motion of the charged particles in the dissipative instability of the under and over-limiting currents of a relativistic electron beam in a fully magnetized beam-plasma waveguide is investigated. It is shown that by increasing the temperature of the plasma electrons, the resonant frequency of the waveguide slightly increases and the growth rates of the instability development decreases. In addition, an increase of the temperature of the plasma electron can change the dissipative hydrodynamic instability to the collisionless kinetic instability. Furthermore, the dissipative instability of the overlimiting electron beam is shown to be more sensitive with respect to the electron plasma temperature compared to the underlimiting electron beam case.     

Distribution function of an electron beam in a focusing magnetic field

The distribution function of electrons moving in an axially symmetric focusing magnetic field is constructed. The macromotion and self-field of the beam are taken into account. The nonrelativistic and relativistic limits are discussed. Upon switching off the magnetic field the distribution functions obtained change into the Maxwell-Boltzmann distribution. The motion of charged particles in a focusing magnetic field is the simplest model for investigation of a beam of particles, for example, electrons, in storage or accelerator rings. In accordance with the well-known theorem of N. Bohr, a magnetic field has no effect on the distribution function for a one-dimensional distribution of electrons with respect to the momenta. However, the situation is altered if macromotion occurs in a static system, for example, the revolution of electrons in storage or accelerator rings. Maintaining the focusing of the beam in an equilibrium orbit, the magnetic field thereby affects the electron distribution function. For an actual electron beam the distribution function is determined by the initial conditions of formation of the beam; however, as a result of scattering processes it will approach some steady-state equilibrium distribution function. We will discuss the problem of finding such a distribution function in the nonrelativistic and relativistic cases.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 35–40, July, 1978.The author thanks Professor I. M. Ternov of Moscow University for his constant interest in this research and Professor V. G. Bagrov of Tomsk University for help in the research.     

强流电子束中ν/γ的物理意义

 从Lawson和Humphries公式以及强流束中的储能导出ν/γ的表达式(ν为Budker参数,γ为相对论因子),对它的物理含义作了充分说明。可用它来表征强流束的总体性质,它代表了强流束的自场横向电磁能与轴向动能之比。     

Induced radiation of a beam of channeled relativistic particles

In principle, the possibility of producing a tunable laser on a beam of relativistic channeled particles is shown. A formula for the gain coefficient is obtained. A discussion is presented of the possibility of cooling the relativistic beam using channeling.     

Collective processes in a microsecond relativistic electron beam: Basic rules and mechanisms

Collective processes taking place in the space charge of a microsecond relativistic electron beam with magnetic insulation are considered. The space-time characteristics of the low-frequency and high-frequency oscillations are found, and the effect of the magnetic compression of the beam near the cathode on these oscillations is studied. It is shown that the basic source of the low-frequency oscillations is the collective motion of the space charge, which takes place in crossed electric and magnetic fields near the cathode, while the primary reason for the high-frequency oscillations is two-stream instability in the beam. The possibility of suppressing both types of oscillations by compressing relativistic electron beams near the cathode is demonstrated. The effect of nonuniform magnetic fields, including their effect on the cathode plasma motion, is elucidated.     

On the propagation of a paraxial beam of charged particles in an external electromagnetic field

A small-angle approximation method as applied to a curvilinear beam of relativistic particles in mutually orthogonal uniform magnetic and nonuniform electric fields is elaborated. Analytical solutions to the paraxial equation for curvilinear beams of charged particles are obtained.     

Calculation of the Relativistic Correction in Terms of the Oscillator Representation

A procedure is proposed for the calculation of the corrections associated with the relativistic motion and spin interaction of particles in a system of a few bodies. The relativistic corrections for the Coulomb and Cornell potentials are determined from the relativistic generalization of the Schrödinger equation. The slope of the Regge trajectory and the masses of mesons are calculated taking the relativistic correction into account.     

Dynamical chaos in the motion of fast charged particles in crystals

It is demonstrated that the dynamical chaos effect can occur both for channeling and above-barrier motion of relativistic electrons and positrons in a crystal. Distinguishing features of the dynamical chaos in the physical processes that accompany the passage of relativistic particles through crystals are discussed.     

On the electromagnetic radiation of channeled particles in a curved crystal

A simple model calculation of the channeling of charged particles in a curved crystal is presented. The characteristics of the powerful radiation from relativistic particles associated with the motion in a curved channel are discussed.     

相对论返波管振荡器齿状阴极

研究了一种齿状阴极的电子束产生传输过程以及对相对论返波管振荡器产生高功率微波的影响。基于SINUS881加速器,利用束流轰击金属靶观测齿状阴极产生电子束在不同轴向位置上的角向分布,并开展了基于环形阴极和齿状阴极的X波段相对论返波管振荡器的实验研究。对不同齿数及尺寸对电子束流特性、器件输出微波功率和脉冲宽度的影响进行了分析。实验结果表明:当阴极的齿数增加到一定数量时,电子束的横向运动使得电子束在径向逐渐趋于分布均匀;与均匀环形阴极的打靶结果近似,此时,电子束对于相对论返波管振荡器产生微波的功率和脉宽影响不大。     

Classical simulation of relativistic Zitterbewegung in photonic lattices

We present the first experimental realization of an optical analog for relativistic quantum mechanics by simulating the Zitterbewegung (trembling motion) of a free Dirac electron in an optical superlattice. Our photonic setting enables a direct visualization of Zitterbewegung as a spatial oscillatory motion of an optical beam. Direct measurements of the wave packet expectation values in superlattices with tuned miniband gaps clearly show the transition from weak-relativistic to relativistic and far-relativistic regimes.