Electron plasma and wave measurements in a crossed-field amplifier and comparison with numerical simulation

Abstract

Detailed two-dimensional, time-averaged measurements of the electron density and the radio-frequency (RF) field have been made in a crossed-field amplifier. Measurements of the local RF field show gain consistent with that of the amplifier. The highly cycloidal nature of the electron beam used in the device has helped elucidate the wave-electron interaction during amplification. With high RF power levels the cycloidal nature of the electron beam is distorted as the beam smooths out. These density measurements have been directly compared to a numerical simulation that gives reasonable prediction of the measured results. Measurements of the electron energy distribution show that most electrons transfer energy to the RF field during amplification. >