Self-organizing knotted magnetic structures in plasma

Smiet, C.B., Candelaresi, S. , Thompson, A., Swearngin, J., Dalhuisen, J.W. and Douwmeester, D. (2015) Self-organizing knotted magnetic structures in plasma. Physical Review Letters, 115(9), 095001. (doi: 10.1103/PhysRevLett.115.095001)

Abstract

We perform full-magnetohydrodynamics simulations on various initially helical configurations and show that they reconfigure into a state where the magnetic field lines span nested toroidal surfaces. This relaxed configuration is not a Taylor state, as is often assumed for relaxing plasma, but a state where the Lorentz force is balanced by the hydrostatic pressure, which is lowest on the central ring of the nested tori. Furthermore, the structure is characterized by a spatially slowly varying rotational transform, which leads to the formation of a few magnetic islands at rational surfaces. We then obtain analytic expressions that approximate the global structure of the quasistable linked and knotted plasma configurations that emerge, using maps from S 3 to S 2 of which the Hopf fibration is a special case. The knotted plasma configurations have a highly localized magnetic energy density and retain their structure on time scales much longer than the Alfvénic time scale.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Candelaresi, Dr Simon
• Authors: Smiet, C.B., Candelaresi, S., Thompson, A., Swearngin, J., Dalhuisen, J.W., and Douwmeester, D.
• College/School: College of Science and Engineering > School of Mathematics and Statistics > Mathematics
• Journal Name: Physical Review Letters
• Publisher: American Physical Society
• ISSN: 0031-9007
• ISSN (Online): 1079-7114
• Published Online: 24 August 2015