Effect of plasma and dielectric loading on the slow-wave properties of a traveling-wave tube

The dispersion characteristics of a helix-loaded traveling-wave tube (TWT) when a dielectric or plasma is introduced into the system are discussed. The dispersive properties of the dielectric-supported helix waveguide are examined for different geometric parameters of the helix waveguide. The dispersion relation of the helix mode is upshifted by omega /sub p//sup 2/ cos/sup 2/ phi when plasma is introduced in the device, where omega /sub p/ and phi are the electron plasma frequency and the pitch angle of the helix, respectively.<
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