An Investigation of Surface Waves and Their Amplification by Beam/Plasma Interaction.
STANFORD UNIV CA INST FOR PLASMA RESEARCH
Pagination or Media Count:
An investigation is described of the propagation of surface waves on a plasma column, and their interaction with an electron beam penetrating the plasma. Apart from its basic plasma physics aspects, the study has been carried out with the aim of assessing the potential for application of this mechanism of amplification, and its coupling characteristics. The dispersion relation for plasma surface waves is first examined for several geometries in which the column is surrounded by one or two dielectric layers, with and without a surrounding conducting waveguide. For a practical geometry, and for the case of an electron beam filling the plasma, the dispersion relation for the combined beamplasma system is analyzed according to general criteria for determining instability and wave types. A brief examination is made of the dispersion relation for the situation where the beam only partially fills the plasma. Preliminary experiments are described in which an attempt was made to measure growth in the surface wave mode, and to relate the measurements to the theory. Author
- Electrical and Electronic Equipment
- Plasma Physics and Magnetohydrodynamics