I thought of using Comsol, which is a general purpose physics modeling program, that can combine thermal, electrical and many other phenomena together in one simulation. However until recently they could not easily handle plasmas. They have now just released a new module http://www.comsol.com/products/plasma/ which may make it easier.
It won’t be up to the task of modeling the later stages of the pinch & plasmoid, but may be sufficient for a mock-up of the axial & first part of the radial phase. To let a full 3D simulation run any further would need the inclusion of higher order terms in the equations and serious amounts of computing power.
