Numerical investigation of transients in the SSPX Spheromak.

Nonlinear plasma simulations of the Sustained Spheromak Physics Experiment demonstrate the role of transient effects in establishing a toroidal magnetic structure that confines internal energy. Magnetohydrodynamics modeling with temperature-dependent transport coefficients compares well with experimental measurements and shows that the second current pulse improves confinement by keeping the q profile from falling below the value of 1/2, suppressing resonant m = 1, n = 2 fluctuations.