SCALING STUDIES OF SPHEROMAK FORMATION AND EQUILIBRIUM

Formation and equilibrium studies have been performed on the Swarthmor e Spheromak Experiment (SSX). Spheromaks are formed with a magnetized coaxial plasma gun and equilibrium is established in both small (d(sma ll)=0.16 m) and large (d(large)=3d(small)=0.50 m) copper flux conserve rs. Using magnetic probe arrays it has been verified that spheromak fo rmation 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 f lux conserver dimensions. It has also been verified that equilibrium i s well described by the force free condition del xB=lambda B (lambda=c onstant), particularly early in decay. Departures from the force-free state are due to current profile effects described by a quadratic func tion lambda=lambda(psi). Force-free SSX spheromaks will be merged to s tudy magnetic reconnection in simple magnetofluid structures. (C) 1998 American Institute of Physics.