Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512107
Title: Novel aspects of cyclotron resonance maser theory
Author: Robb, Gordon R. M.
ISNI:       0000 0001 2413 3324
Awarding Body: University of Strathclyde
Current Institution: University of Strathclyde
Date of Award: 1994
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Abstract:
Cyclotron resonance masers (CRMs) are important devices for the generation of high power electromagnetic radiation in the millimetre and sub-millimetre region of the electromagnetic spectrum. In these devices, an electromagnetic wave is amplified by its interaction with a beam of relativistic electrons gyrating in a magnetostatic field. This thesis presents the results of novel theoretical investigations into the physical processes which occur in a CRM amplifier. The basis of these investigations was a system of universally scaled evolution equations which describe the linear and nonlinear evolution of the CRM interaction. These equations involve a minimum number of free parameters and allow a general analysis of the interaction. By considering various limits of the free parameters, the physical processes which occur in the steady-state limit were identified and studied using numerical analysis and an extensive linear analysis based on the method of collective variables. Neglecting the recoil of the electrons, it was shown that the universally scaled evolution equations could be written as a set of Hamilton's equations. The behaviour of this Hamiltonian system was investigated via a phase space analysis for some specific cases of the free parameters. In addition, it was shown that it is possible to approximately describe the evolution of the electromagnetic field up to saturation in a CRM amplifier by an analytically solveable Landau-Ginzburg equation. Including slippage effects, it was shown that for electron beams with relativistic axial velocities, in addition to the steady-state evolution of the electromagnetic field, superradiant field evolution could also occur. Superradiant phenomena were studied using an heuristic dissipative model, an extensive linear analysis and a nonlinear numerical analysis. The existence of weak superradiance, involving short electron pulses and low radiation intensities, and strong superradiance, involving long electron pulses and high intensity spikes of radiation, was demonstrated.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.512107  DOI: Not available
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