Numerical simulations of kink instability in line-tied coronal Loops

The results from numerical simulations carried out using a new shock-captur ing, Lagrangian-remap, 3D MHD code, Lare3d are presented. We study the evol ution of the m = 1 kink mode instability in a photospherically line-tied co ronal loop that has no net axial current. During the non-linear evolution o f the kink instability, large current concentrations develop in the neighbo urhood of the infinite length mode rational surface. We investigate whether this strong current saturates at a finite value or whether scaling indicat es current sheet formation. In particular, we consider the effect of the sh ear, defined by r phi'/phi where phi = LBtheta/rB(z) is the fieldline twist of the loop, on the current concentration. We also include a non-uniform r esistivity in the simulations and observe the amount of free magnetic energ y released by magnetic reconnection.