Numerical simulations of kink instability in line-tied coronal Loops

¹ School of Mathematics and Statistics, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, Scotland
² Space and Astrophysics Group,Physics Department, University of Warwick, Coventry, CV4 7AL, UK
³ Koninklijke Sterrenwacht van Belgie, Ringlaan 3, 1180 Ukkel, Belgium

Corresponding author: C. L. Gerrard, cath@mcs.st-and.ac.uk

Received: 13 December 2000
Accepted: 9 May 2001

Abstract

The results from numerical simulations carried out using a new shock-capturing, Lagrangian-remap, 3D MHD code, Lare3d are presented. We study the evolution of the kink mode instability in a photospherically line-tied coronal loop that has no net axial current. During the non-linear evolution of the kink instability, large current concentrations develop in the neighbourhood of the infinite length mode rational surface. We investigate whether this strong current saturates at a finite value or whether scaling indicates current sheet formation. In particular, we consider the effect of the shear, defined by where is the fieldline twist of the loop, on the current concentration. We also include a non-uniform resistivity in the simulations and observe the amount of free magnetic energy released by magnetic reconnection.