Knots in plasma

Smiet, C.B. (2017)

Doctoral Thesis

A plasma is an ionized gas with very low electrical resistivity. As such, magnetic field lines are 'frozen in' and move with the fluid. Magnetic field lines that are linked, knotted and tangled, cannot be undone by the fluid motions.
In this thesis we investigate how this linking and knottedness influences the plasma dynamics through numerical simulations. One of the main results is the identification of a novel, self-organizing equilibrium, where every field line is linked with every other one. In such a structure all the field lines lie on toroidal magnetic surfaces, and the entire structure resembles the famous topological structure of the Hopf fibration. This magnetic equilibrium is localized, and kept in balance by a finite external pressure. Through resistive effects the structure slowly expands while the magnetic energy is dissipated.
This research, and the novel structures identified have implications for nuclear fusion research and the study of astrophysical plasma phenomena.

 

• Helicity
• Magnetohydrodynamics
• Magnetic reconnection
• Self-organization
• Magnetic topology

• All authors: Smiet, C.B.
• Supervisor: Bouwmeester, D.
• Committee: Ebert, U.; Hornig, G.; Hudson, S.R.; Eliel, E.R.; Saarloos, W. van; Dood, M.J.A. de
• Qualification: Doctor (dr.)
• Awarding Institution: Leiden Institute of Physics (LION), Science, Leiden University
• Date: 2017-06-20
• Title of host publication: Casimir PhD Series
• ISBN (print): 9789085932994
• Name: 2017-11
• Sponsorship: NWO graduate programme