HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Flux Ropes as Singularities of the Vector Potential

Abstract : A flux rope is a domain where a twisted magnetic field [ B] is concentrated; it can be described as the core of a singularity of the outer field or the outer vector potential [ A] (Kleman and Robbins in Solar Phys. 289, 1173, 2014). This latter case, occurring when the outer field is vanishing, is mathematically analysed for a straight infinite rope. Concepts from condensed-matter physics defect theory are used: the flux [Φ], measured as ∮ C Aṡd s along any loop [ C] surrounding the rope, is a topological constant of the theory. A flux rope with a small outer magnetic field can be treated as a perturbation of the above. This theoretical framework allows for the use of classical configurations inside the core, e.g. the linear force-free field (LFFF) Lundquist model or the nonlinear (NLFFF) Gold-Hoyle model, but restricts the number of stable solutions: they are quantised into strata of increasing energies (an infinite number of strata in the first case, only one stratum in the second case); each stratum is defined by a number 2 πζ= b/ r 0, where b is the periodicity along the axis of the rope and r 0 is its radius, and the rope is made of a continuous set of stable states. We also analyse the merging of identical flux ropes (belonging to the same stratum), with conservation of the relative magnetic helicity: they merge into a unique rope of the first stratum, with a considerable release of energy.
Document type :
Journal articles
Complete list of metadata

https://hal-insu.archives-ouvertes.fr/insu-03579987
Contributor : Nathalie Pothier Connect in order to contact the contributor
Submitted on : Friday, February 18, 2022 - 2:00:35 PM
Last modification on : Sunday, February 20, 2022 - 3:32:44 AM

Links full text

Identifiers

Citation

M. Kleman. Flux Ropes as Singularities of the Vector Potential. SOLAR PHYSICS, 2015, 290, pp.707-725. ⟨10.1007/s11207-015-0647-6⟩. ⟨insu-03579987⟩

Share

Metrics

Record views

3