INVESTIGATION OF LINEAR BEAM AND NEW CONCEPTS OF MICROWAVE POWER. VOLUME V. INTERACTION OF HIGH-POWER ELECTRON BEAM AND PLASMA,

Abstract : A Penning discharge was used to generate in hydrogen a plasma suitable for use in a microwave electron beam plasma amplifier. Plasma densities on the order of 10 to the 11th power electrons per cubic centimeter were obtained. A two-fluid theoretical model of the plasma was developed in order to explain the operation of the discharge. It is supported by diagnostic measurements of two kinds, microwave-cavity measurements and probe measurements. The detuning of a resonant microwave cavity was found to be a fast and reliable method for measuring the average plasma density. Probe measurements provided information on the average plasmaelectron energies and on the shape of the radial plasmadensity profile. The design of the cavities is described in full, and equivalent circuit concepts are found to be useful in interpreting the experimental results. The probe and cavity measurements both showed that plasma densities that will permit the operation of a beam-plasma amplifier at S-band can be generated in the present system using hydrogen gas. (Author)