Magnetohydrodynamic current drive for fusion confinement

Summary form only given, as follows. A closed current loop in a plasma is an effective means of confining plasma for fusion reactions, and is widely used in the tokamak and a variety of other toroidal systems. The problem is that the current loops are typically formed by induction, and therefore limited to pulsed operation. Methods such as helicity injection or the bootstrap effect to achieve steady state operation have been investigated with the tokamak, but tend to be complex. Magnetohydrodynamic current drive, in contrast, offers a simple means of forming and maintaining steady-state current loops in fusion reactors. Plasma flow through an axially symmetric converging magnetic stator field acts as an internally shorted magnetohydrodynamic generator that forms a freestanding stationary current loop in the plasma stream. The current loop is sustained by flow energy, and remains at steady state as long as the flow continues. Further, refueling is automatic. The through flow of plasma brings in fresh fuel and removes reaction products.