Linear theory of magnetized ion-channel free-electron laser

Abstract

A theory of wiggler pumped ion-channel free-electron laser (WPIC-FEL) and an axial magnetic field is presented. The motion of a relativistic electron is analyzed in the field configuration consisting of a helical wiggler magnetic field, a uniform axial magnetic field, and an electrostatic electric field produced by an ion-channel. An equation for the function Φ, which determines the rate of change of axial velocity with energy, is derived. Numerical calculations are made to illustrate the effects of two electron beam guiding devices on the trajectories. By means of linear fluid theory, the sixth-degree polynomial dispersion equation for electromagnetic and space-charge waves is derived. The dependence of growth rate-frequency curves on the ion-channel frequency and axial magnetic field is studied numerically.

Nonlinear simulation of TM mode free electron laser in rectangular waveguide with ion-channel

“…then we substitute current density (equation ( 9)) in equation (10) and perform operator (11) on both sides. By doing a straight forward calculation, we obtain the complex evolution equation for amplitude and phase of wave:…”

“…Free electron laser (FEL) devices can operate as a broadband high power microwave (HPM) source in which the kinetic energy of bunched electrons are converted to the energy of a co-propagating wave in the presence of a wiggler [1,2]. Essentially, the mechanism of the wiggler could be based on electrostatic, magnetostatic or electromagnetic periodic fields and have varieties of configurations [3][4][5][6][7][8][9][10] which have been widely studied theoretically and experimentally. Among them, planar wigglers are especially easy to construct and the arrangement of implied magnets determines the polarization of radiated power [11,12].…”

Filamentation instability of electron/ion beams in magnetized plasma waveguide

“…The interaction of charged particles with plasma has been an active area of research due to its potential applications in inertial confinement fusion (ICF) (Tabak et al 1994;Srinivasan et al 2012), conventional accelerators and free electron lasers (Freund and Antonsen1996;Hasanbeigi et al 2010;Huang et al 2012;Sadegzadeh et al 2012), plasma electronics (Shenggang et al 2000;Lai et al 2011), astrophysics (Klassen et al 2003Bret 2009), etc. Charged particle beams, as particles in the solar wind or particles accelerated in the magnetosphere and the ionosphere, interact with the ambient plasma.…”

Dispersion relation and growth rate for a corrugated channel free-electron laser with a helical wiggler pump

“…Ion-channel guiding (ICG) in free-electron lasers (FELs) has been a subject of great interest in two decades. [1][2][3][4][5] If an intense relativistic electron beam is injected into a neutral plasma in a blow-out regime, when the electron beam density is higher than the plasma density, plasma electrons are ejected electrostatically by the beam space charge. The beam electrons are then electrostatically attracted by the positive ions.…”