Scaling studies of spheromak formation and equilibrium

Formation and equilibrium studies have been performed on the Swarthmore Spheromak Experiment (SSX). Spheromaks are formed with a magnetized coaxial plasma gun and equilibrium is established in both small (d(small)=0.16 m) and large (d(large)=3d(small)=0.50 m) copper flux conservers. Using magnetic probe arrays it has been verified that spheromak formation is governed solely by gun physics (in particular the ratio of gun current to flux, mu(0)I(gun)/Phi(gun)) and is independent of the flux conserver dimensions. It has also been verified that equilibrium is well described by the force free condition del xB=lambda B (lambda=constant), particularly early in decay. Departures from the force-free state are due to current profile effects described by a quadratic function lambda=lambda(psi). Force-free SSX spheromaks will be merged to study magnetic reconnection in simple magnetofluid structures. (C) 1998 American Institute of Physics.