Effect of a conducting waveguide on the dynamics of ion hose instability of a relativistic electron beam propagating in the ion focusing regime

We analyze the effect of a conducting waveguide on the dynamics of the ion hose instability of a relativistic electron beam propagating in a rarefied gas-plasma medium in the ion focusing regime. It is shown using the linear theory of the instability under investigation that a decrease in the waveguide radius noticeably stabilizes the ion hose instability. In addition, it is noted that radial narrowing of the ion channel relative to the beam considerably decreases the amplitude of hose oscillations.     

Calculation of force exerted by the Ohmic plasma channel on a relativistic electron beam propagating in a dense gas-plasma medium

The problem on the interaction of an Ohmic plasma channel displaced in the transverse direction with a paraxial azimuthally symmetric relativistic electron beam propagating in a dense gas-plasma medium is considered. The formula for determining the force of the beam-plasma interaction is derived using the “hard” model of the beam and the channel in the case of an arbitrary displacement of the symmetry axis of the plasma channel relative to the corresponding axis of the beam. The forces are calculated in the Bennett and Gauss approximations for the radial profiles of the beam and the channel.     

Interaction of a relativistic electron beam with a spiral waveguide

The nonlinear period in the interaction of a relativistic electron beam (REB) with an electromagnetic wave in a spiral waveguide at the stage of saturation is investigated for a Cherenkov interaction mechanism. On the basis of the kinetic equation and laws of energy and momentum conservation, analytical relations are obtained, allowing the efficiency of excitation and amplification of the electromagnetic wave to be studied using REB in a retarding structure. The results of the analysis are in good agreement with the data of actual and numerical experiments.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 31–36, May, 1988.It remains to thank É. A. Perel'shtein, Yu. I. Aleksakhin, and their colleagues for discussion of the results.     

The influence of current neutralization and multiple Coulomb scattering on the spatial dynamics of resistive sausage instability of a relativistic electron beam propagating in ohmic plasma

Technical Physics - The influence of the current neutralization process, the phase mixing of the trajectories of electrons and multiple Coulomb scattering of electrons beam on the atoms of the...     

同轴波导环形相对论电子束空间极限电流

得到了1维条件下电子均匀分布时,环形电子束在同轴波导内轴向传输的空间极限电流解析表达式。通过讨论解析式在薄电子束和波导内导体半径为0等极限条件下的近似情况,分析了其合理性。在电子束非均匀分布的条件下,对空间极限电流进行了数值求解,并与解析计算结果进行了比较。理论研究表明：环形电子束在同轴波导内具有较圆柱波导内更高的空间极限电流,而且当电子束靠近波导壁时,空间极限电流会显著提高。     

箔聚焦强流相对论环形束在同轴波导中的传输

 结合箔聚焦和静电线聚焦的特点,对箔聚焦强流相对论环形电子束在同轴波导中的传输进行了研究。通过数值求解电势满足的泊松方程,得到电势、电场分布及系统的空间电荷限制流,并根据电子的运动方程得到包络电子的平衡条件及其运动轨迹。     

箔聚焦强流相对论环形束在同轴波导中的传输

结合箔聚焦和静电线聚焦的特点,对箔聚焦强流相对论环形电子束在同轴波导中的传输进行了研究。通过数值求解电势满足的泊松方程,得到电势、电场分布及系统的空间电荷限制流,并根据电子的运动方程得到包络电子的平衡条件及其运动轨迹。     

同轴波导环形相对论电子束空间极限电流

得到了1维条件下电子均匀分布时,环形电子束在同轴波导内轴向传输的空间极限电流解析表达式。通过讨论解析式在薄电子束和波导内导体半径为0等极限条件下的近似情况,分析了其合理性。在电子束非均匀分布的条件下,对空间极限电流进行了数值求解,并与解析计算结果进行了比较。理论研究表明:环形电子束在同轴波导内具有较圆柱波导内更高的空间极限电流,而且当电子束靠近波导壁时,空间极限电流会显著提高。     

A planar relativistic electron beam in a plasma channel bounded by conducting walls

The force interaction of a relativistic electron beam with a plasma in a channel bounded by planegeometry highly conducting walls is studied. The steady-state interaction regime, ω=ku, is analyzed using the model of a cold collisional electron plasma. The formulas for the transverse component of the force acting on the beam electrons are derived for an arbitrary deviation of the beam from the symmetry plane of the channel.     

Fluctuations of the propagating beam field in a lens waveguide

It is well known that light beams propagated through a turbulent medium such as the atmosphere or the air between optical lenses suffer fluctuations of the field in respect of its amplitude and phase. This paper investigates the fluctuation distributions of a laser beam propagating through a lens waveguide which consists of a sequence of optical lenses placed in a randomly inhomogeneous medium. By using a Rytov approximation approach, the mean-square values of fluctuations are obtained in terms of log-amplitude and phase of the beam field. The results show that as the light beam propagates through the lens waveguide, the mean-square fluctuations increase with periodic variations corresponding to a period of lens spacing and that a singular phenomenon of fluctuation reduction at each focus of the beam is evident at larger beam spot sizes.     

Transverse dynamics of a low-density relativistic electron beam propagating in the plasma along an external magnetic field

It is shown that a low-density relativistic electron beam can be transported under conditions of (i) periodic oscillation of the beam radius, (ii) unlimited beam expansion, and (ii) pinching. Analytical expressions for the radial evolution of the beam under these transport condition are obtained.     

Dissipative instability of a highly relativistic electron beam through the excitation of surface waves on a conducting medium

The possibility of the dissipative instability of a relativistic electron beam streaming near a conducting medium is investigated. The development of this dissipative beam instability through the surface wave excitation slightly disturbs the beam leading to the slightly heating of the conducting medium.     

Wave growth rate in a cylindrical metal waveguide with ion-channel guiding of a relativistic electron beam

This paper addresses the formulae and numerical issues related to the possibility that fast wave may be grown when a relativistic electron beam through an ion channel in a cylindrical metal waveguide.To derive the dispersion equations of the beam-wave interaction,it solves relativistic Lorentz equation and Maxwell’s equations for appropriate boundary conditions.It has been found in this waveguide structure that the TM 0m modes are the rational operating modes of coupling between the electromagnetic modes and the betatron modes.The interaction of the dispersion curves of the electromagnetic TM 0m modes and the upper betatron modes is studied.The growth rates of the wave are obtained,and the effects of the beam radius,the beam energy,the plasma frequency,and the beam plasma frequency on the wave growth rate are numerically calculated and discussed.