Microwave Emission from an Anisotropy Instability in a High-Current Relativistic Electron Beam

Abstract

A momentum anisotropy, created by injecting an electrostatically unneutralized annular electron beam through various foils, is shown experimentally to lead to high-power microwave emission. The radiation occurs at a frequency such that the phase velocities of cyclotron waves on the beam and the T${\mathrm{E}}_{01}$ mode in the guide are equal.