Influence of Wall Impedance on the Electron Cyclotron Maser Instability.
Abstract
The influence of finite wall impedance effects on the cyclotron maser instability of a hollow electron beam is investigated. The stability analysis is carried out within the framework of the linearized Vlasov-Maxwell equations, assuming that the beam thickness is much less than the radius of the beam. The formal dispersion relation for azimuthally symmetric electromagnetic perturbations is obtained, including the influence of an arbitrary value of wall impedance. One of the most important features of this analysis is that, for a purely resistive wall, the growth rate of instability is substantially reduced by allowing even a very small amount of resistivity. Moreover, the range of axial wave-numbers corresponding to instability increases rapidly as the wall resistivity is increased. Cyclotron maser stability properties in a dielectric loaded waveguide is also investigated. It is shown that by an appropriate choice of the dielectric constant epsilon and thickness of dielectric material, the bandwidth of instability can be increased more than twice of that for a plain conducting waveguide. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1980
- Accession Number
- ADA086401
Entities
People
- Han S. Uhm
Organizations
- Naval Ordnance Laboratory