Current Maintenance in Tokamaks by Use of Synchrotron Radiation

A tokamak at fusion temperatures generates large amounts of synchrotron radiation. With proper configuration of the walls, this radiation can sustain the current. This is accomplished by a fish-scale wall that preferentially reflects radiation propagating in one direction while absorbing that going oppositely. The wall transfers momentum to the electrons through radiation pressure. A rough theoretical treatment shows that at high temperatures (30-50 keV) sufficient current for a steady-state tokamak may be driven.