Plasma Influence on the Dispersion Properties of Finite-Length, Corrugated Waveguides

We present an experimental study of the electromagnetic properties of transverse magnetic modes in a corrugated-wall cavity filled with a radially inhomogeneous plasma. The shifts of the resonant frequencies of a finite-length, corrugated cavity were measured as a function of the background plasma density and the dispersion diagram was reconstructed up to a peak plasma density of 10¹² cm⁻³. Good agreement with a calculated dispersion diagram is obtained for plasma densities below 5×10¹¹ cm⁻³.