Adiabatic equilibrium calculations of major-radius compression in a tokamak

Equilibrium calculations which conserve adiabatic quantities (magnetic fluxes, particle number and entropy) during major-radius compression in a tokamak have been made by using a flux-surface-averaged description of the plasma behavior in order to solve the two-dimensional plasma equilibrium equation. Boundary conditions are chosen to avoid skin current formation during compression, and the changes of the Ohmic-heating flux required to maintain this condition are determined. Comparisons are made between the plasma parameter variations determined from these computations and the scaling behavior predicted by a large-aspect-ratio approximation to the adiabatic constraints.