Abstract :
The paper discusses a rapid pinch process in which azimuthal currents and their associated axial magnetic fields are used to heat and confine a plasma. A simple one-dimensional model of the fast pinch process is used to show how the temperature attained by the plasma depends upon the discharge parameters and in particular that the energy per particle is proportional to the electric field developed across the plasma surface. Previous work on this form of pinch effect is reviewed and an account is given of preliminary experiments at the Atomic Weapons Research Establishment (A.W.R.E.). The principal features of a toroidal system using azimuthal currents and axial fields to heat and subsequently confine a plasma is presented and the advantages and consequences of this configuration are examined, particularly as compared with a torus using axial currents. After the initial rapid heating process the plasma and magnetic field diffuse into each other and the configuration is similar to that in the Stellarator, with similar stability problems and similar possibilities of continuous operation.