End shorting induced rotation in a ϑ pinch

A possible explanation for the observed rotation in open ended ϑ-pinch devices is shown to result from the shorting out of electric field components at the insulating boundary. The propagation of rotation into the plasma is primarily via torsional Alfvén waves preceded by dispersive precursors. The precursors have spatially and temporally modulated amplitudes. They are due to gyrofrequency oscillations of the plasma and are seen throughout the plasma immediately following the shorting out of the electric field components at the insulators.