McGuire aims to generate the extreme magnetic fields necessary for plasma confinement with superconductors. Currently, the highest temperature we've observed superconductivity capabilities (in specially engineered materials) is around -135C. If he wants to drive turbines with heat generated from the fusion core, he'll require at least a 200C temperature difference across a material that needs to have extreme magnetic permeability. This material is pictured in orange, residing between the confinement vessel's walls, and the superconducting electromagnets.
Yeah we're talking about enthalpy in a case of very extreme temperatures, over a very small area, in a close time frame. It's an interesting though experiment, and I'll of course be happy if it works, but it seems like business magic more than any real science.