Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.805497
Title: Nonlinear wave-particle resonance in deterministic and stochastic kinetic plasmas
Author: Woods, Benjamin J. Q.
Awarding Body: University of York
Current Institution: University of York
Date of Award: 2019
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Abstract:
In kinetic plasma physics, BGK modes are ubiquitous solutions to the Vlasov equation, with particles travelling along orbits where the single particle energy is conserved. Approximate extensions of these exact solutions have been successfully used in the past to understand the formation and evolution of ‘holes’ and ‘clumps’, coherent structures on the particle distribution function which under certain conditions form in the nonlinear phase of the evolution of kinetic plasmas. In this thesis, analytical results are shown which consider perturbations and deformations to BGK orbits, allowing one to robustly construct more exotic orbits that allow for mode growth and frequency chirping. Computational results produced using the DARK code are presented, examining stochastic and deterministic populations in a 1D electrostatic plasma, and how they affect electrostatic waves exhibiting Landau resonance, based on Berk-Breizman models. A model is presented for parametric mode-mode destabilisation via holes and clumps interacting via the background distribution. Finally, work using the machine learning framework ERICSON is presented, analysing frequency spectrograms of magnetic perturbations in Alfvénic and sub-Alfvénic frequency ranges.
Supervisor: Vann, Roddy G. L. Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.805497  DOI: Not available
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