Special cylindrical equilibria of a compressing flux-conserving tokamak

Evolution of a tokamak equilibrium with adiabatic compression and rapid beam heating is analyzed using a cylindrical flux-conserving model. The time-dependent relation between the plasma β and the pressure profile is obtained, which is necessary to avoid the increase of the longitudinal field at the plasma surface or the expansion of the plasma column due to rapid beam heating. As for three-dimensional adiabatic compression the current peaking of the order of β appears on the compressing frame, while two dimensional compression does not lead to the change of profiles. (author)