Nonlinear wave interactions and evolution of a ring-beam distribution of energetic electrons

Abstract

A ring-beam distribution function of moderately relativistic electrons is unstable to electromagnetic and electrostatic waves. The results obtained in numerical simulations show that electromagnetic radiation corresponding to the normal modes of the background plasma is observed to grow even in the presence of a strong electrostatic instability and becomes very strong when the growth of the electrostatic Langmuir waves is minimized, and that the instability process is best described as a beam cyclotron resonance. Another strong radiation generated by the ring beam is the Z mode which is coupled to the electrostatic Langmuir wave. Under certain circumstances, these mechanisms may be significant in astrophysical situations.

Nonlinear Saturation of Cyclotron Maser Instability Associated with Energetic Ring-Beam Electrons

“…The necessary condition for the CMI is that a positive gradient along the perpendicular velocity is present in the velocity distribution function [3]. With this in mind one can envision that energetic electrons possessing a ring-beam distribution [4,5] can result in the CMI. Such a model is of interest because not only may it occur in the solar corona and quasiperpendicular shocks [5,6], but also the ring-beam case appears far much more efficient than the loss-cone case [4].…”

“…With this in mind one can envision that energetic electrons possessing a ring-beam distribution [4,5] can result in the CMI. Such a model is of interest because not only may it occur in the solar corona and quasiperpendicular shocks [5,6], but also the ring-beam case appears far much more efficient than the loss-cone case [4]. This model of the CMI has been applied to explain type II and type III solar radio emissions [6].…”

Excitation of azimuthal surface waves by annular electron beams in the range of electron cyclotron frequency

“…Однак теорію пучково-плазмових нестійкостей не можна вважати повністю завершеною, оскільки процес взаємодії потоків заряджених частинок із власними хвилями хвилеводів істотно залежить від великої кількості факторів, у тому числі від дисперсійних властивостей цих хвиль, їхньої поляризації, просторового розподілу поля хвилі, геометрії та конструктивних особливостей хвилеводу. З цієї точки зору перспективним видається вивчення взаємодії кільцевих пучків заряджених частинок із хвилеводами, що наповнені плазмою [8][9][10][11][12][13][14]. У цьому випадку слід очікувати підвищення коефіцієнта корисної дії (ККД) таких приладів у порівнянні з пристроями, що працюють на поздовжніх пучках.…”

Excitation of Azimuthal Eigen Modes by Modulated Annular Electron Beam

“…Solution of the set of equations for amplitude (6) and phase (7) of the AMs envelope, motion equations for the beams' electrons (10)- (12) has been found by the Runge-Kutta method of the fourth order, which is widely used for the research of such problems [1,2,14,15]. Quantity of the beams' macro -particles was assumed to be here N = 2000.…”

“…Results of studying beam-plasma interaction are widely utilized in different branches of plasma physics, e.g., for studying plasma heating in fusion devices [8,9], for studying generation of high power radiation in various plasma electronic devices [10][11][12][13][14][15]. Moreover, the relativistic electron beams are offered to be used even for plasma confinement.…”