Theoretical Studies in Crossed-Field Devices
Abstract
Theoretical studies have been made on the nonlinear operating regimes of crossed-field vacuum devices, in the nonrelativistic regime. The main interaction is a wave-particle interaction between those drifting electrons whose velocities match the phase velocity of the RF wave in the slow-wave structure. The theory is based on two elementary modes: a DC average background mode and an RF oscillating mode. These elementary modes interact nonlinearly via a nonlinear diffusion process, for which there are sometimes stationary equilibrium states. When these stationary states do exist, the operating characteristics of the modes have been detailed, and criteria for determining the operating parameter regimes have been given. This work suggested that such devices should not operate at more than about 20% above the Hartree voltage, due to the parametric generation of intense subharmonic modes, at voltages higher than this. The work also found that whenever a cyclotron resonance did occur inside the plasma region, the growth rate would essentially vanish. Thus such regimes should be avoided since the amplification would be weak, at best.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 14, 1999
- Accession Number
- ADA368681
Entities
People
- David J. Kaup