Plasma confinement in the toroidal multipole

PLASMA CONFINEMENT SYSTEMS of various kinds have been studied in many countries for more than 15 years, with the attainment of controlled thermonuclear fusion as the aim. Most of the effort, particularly recently, has been devoted to stellarators; the largest machines are the C Stellarator at the plasma physics laboratory of Princeton University and the Tokomak at the Kurchatov Institute in Moscow. More recently experiments with toroidal multipole devices have shown that the containment time may be at least ten times that for stellarators, by reducing the loss of plasma density through “pumpout” or Bohm diffusion, a turbulence effect that had been the limiting factor of earlier machines.