Relaxation toward states of minimum energy in a compact torus

Abstract

A finite-difference, resistive, magnetohydrodynamic code is used to follow the long-time evolution of decaying nonequilibrium states inside a rigid, perfectly conducting cylindrical boundary. The energy-to-magnetic helicity ratio decays toward a minimum, in accord with a conjecture of Taylor. The magnetic Reynolds number is considerably higher than the mechanical Reynolds number for the regime considered. The energy, which is mostly magnetic, tends to decay in bursts associated with current filamentation and magnetic reconnection.