Premium
MHD Collimation Mechanism in Arched Flux Ropes Characterized Using Volumetric, Time‐Dependent B ‐Vector Measurements
Author(s) -
Haw Magnus A.,
Bellan Paul M.
Publication year - 2017
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl074505
Subject(s) - physics , rope , magnetohydrodynamics , radius , collimated light , flux (metallurgy) , magnetic flux , current (fluid) , solar radius , solar prominence , mechanics , astrophysics , magnetic field , optics , coronal mass ejection , solar wind , materials science , laser , computer security , structural engineering , quantum mechanics , computer science , engineering , metallurgy , thermodynamics
Laboratory measurements of B ( x , t ) in a volume enclosing portions of two arched flux ropes show flux rope collimation driven by gradients in axial current density. These measurements verify the three predictions of a proposed MHD collimation mechanism: (1) axial magnetic forces exist in current channels with spatially varying minor radius, (2) these forces can drive counterpropagating axial flows, and (3) this process collimates the flux rope. This mechanism may explain the axial uniformity of solar loops and is relevant to other systems with current channels of varying minor radius such as solar prominences and astrophysical jets.