Microwave Interferometry for Plasma Studies

Abstract

A beam of microwave radiation is a powerful and penetrating means of exploring the density and temperature of laboratory plasmas while causing minimal perturbation of the plasma. To a wave of frequency greater than the electron plasma frequency the plasma behaves like a dielectric, causing a change in the "optical" path which, when measured by interference techniques, yields the average electron density. The attenuation of the probing wave can give the collision frequency and hence the plasma temperature.