Abstract
The main part of the work described in this thesis is concerned with the propagation of electromagnetic waves along coaxial lines partially filled with a plasma. The dispersion curves for the propagation of both fast and slow waves have been theoretically predicted while considering the plasma to possess a uniform electron density. Also the dispersion curve for the propagation of a certain slow wave has been predicted while considering the plasma to possess a certain non-uniform electron density. Trivelpiece's slow wave approximation has been applied in the analysis pertaining to the slow wave propagation. It has not been possible for the fast wave dispersion curves to be predicted in the non-uniform plasma case. However, a transmission line technique has been developed which is capable of predicting very accurate approximations to the fast wave Brillouin diagrams, and this transmission line technique is able to predict the Brillouin diagrams for fast wave propagation in non-uniform plasmas. Electromagnetic wave propagation in a coaxial line completely filled with a magnetized plasma has been theoretically investigated, and the Brillouin diagrams pertaining to both fast and slow wave propagation have been plotted. The transmission line technique is capable of predicting very accurate approximations to the fast wave Brillouin diagrams in the case of magnetized plasmas. The existence of both fast and slow wave propagation along annular plasmas in the absence of a d.c. magnetic field has been experimentally demonstrated and experimental Brillouin diagrams have been obtained and compared with theory. Electromagnetic wave propagation along a circular wave guide containing a discharge tube has been investigated as well as propagation along a coaxial line. The discrepancies between theory and experiment have been shown to be due, at least in part, to the non-unifom nature of the experimental plasma.