Undulation of a magnetized electron beam by a periodic ion channel

Abstract

Electron‐beam dynamics are calculated for an electron beam propagating parallel to a uniform magnetic field through a periodic ion density channel. Results show that resonant excitation of transverse electron oscillations occurs when the wavelength of the ion density variation equals the axial distance over which an electron cyclotron orbit occurs. This indicates that a periodic ion channel behaves as an electrostatic undulator with magnetoresonance. It is found that periodic ion densities of 1011–1012 cm−3 are required to achieve transverse electron velocities comparable to those of a typical magnetostatic undulator.