Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published 2003 | Submitted
Journal Article Open

Why helicity injection causes coronal flux tubes to develop an axially invariant cross-section

Abstract

It is shown that electric current flowing along an axially non-uniform magnetic flux tube produces an associated non-linear, non-conservative axial MHD force which pumps plasma from regions where the flux tube diameter is small to regions where it is large. In particular, this force will ingest plasma into the ends of a fat, initially potential flux tube and then pump the ingested plasma towards the middle bulge, thereby causing mass accumulation at the bulge.The ingested plasma convects frozen-in toroidal magnetic flux which accumulates at the middle as well. Flux accumulation at the bulge has the remarkable consequence of causing the bulge to diminish so that the flux tube becomes axially uniform as observed in coronal loops. Stagnation of the convergent plasma flow at the middle heats the plasma. A small number of tail particles bouncing synchronously between approaching fluid elements can be Fermi-accelerated to very high energies. Since driving a current along a flux tube is tantamount to helicity injection into the flux tube, this mass ingestion, heating, and straightening should be ubiquitous to helicity injection processes.

Additional Information

© 2003 COSPAR. Published by Elsevier Ltd. Supported by USDOE Grant DE-FG03-97ER54438.

Attached Files

Submitted - 0212093.pdf

Files

0212093.pdf
Files (122.3 kB)
Name Size Download all
md5:513e9a00d850a050e9ddb36978586291
122.3 kB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 18, 2023