A planar coaxial electrostatic helicity source is used for studying the relaxation process intrinsic to spheromak formation. Experimental observations reveal that spheromak formation involves: (1) breakdown and creation of a number of distinct, arched, filamentary, plasma-filled flux loops that span from cathode to anode gas nozzles, (2) merging of these loops to form a central column, (3) jet-...

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 m = 1 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...

The Caltech experiment described here produces plasmas relevant to both astrophysical and fusion energy studies. A disk-shaped set of electrodes mounted on the inside of a meter-scale vacuum chamber provides the energy to break a neutral gas, provided at the electrodes only, down into a plasma. The plasma starts as eight loops, and then self-organizes into a single magnetically driven collimate...

We characterize the coarsening dynamics associated with a convective Cahn-Hilliard equation (cCH) in one space dimension. First, we derive a sharp-interface theory through a matched asymptotic analysis. Two types of phase boundaries (kink and anti-kink) arise, due to the presence of convection, and their motions are governed to leading order by a nearest-neighbors interaction coarsening dynamic...

Sheared toroidal rotation is found to increase the ideal external kink stability limit, thought to be the ultimate performance limit in fusion tokamaks. However, at rotation speeds approaching a significant fraction of the Alfvén speed, the toroidal rotation shear drives a Kelvin–Helmholtz-like global plasma instability. Optimizing the rotation profile to maximize the pressure before encounteri...

We have considered the dynamics of kinks in smectic-C liquid crystal in uniformly rotating and oscillating electric or magnetic fields. In tilted oscillating fields our results are at variance with those of earlier investigations which predict chaos in this geometry for a p kink. On the other hand, we find that the velocity and the structure of a p kink are oscillatory with the frequency of the...

Global hybrid simulations of energetic particle effects on the n=1 internal kink mode have been carried out for tokamaks. For the Internationa Thermonuclear Experimental Reactor (ITER) [ITER Physics Basis Editors et al, Nucl. Fusion 3 ̄ 9, 2137 (1999).], it is shown that alpha particle effects are stabilizing for the internal kink mode. However, the elongation of ITER reduces the stabilization e...

Two lines of observational evidence are used to infer that the MHD helical kink instability is associated with solar eruptions. The sense of twist and writhe are determined in images of 7 erupting filaments obtained at 10830 Å, 1600 Å, 195 Å and 171 Å. In every case the sense of twist is the same as the sense of writhe, as required for a kink. From images in the soft X-ray and EUV spectrum, mea...