Production and maintenance of high poloidal beta tokamak plasmas by means of rf current drive

It is shown that in tokamak plasmas sustained by rf current drive, the contribution of the suprathermal rf-driven electron population to the poloidal beta (${\beta }_p$) can be substantial if the total current is comparable to the Alfvén critical current, $I_A$=(4πmcv/${\mu }_0$ec)γ. Equilibria with values of ε${\beta }_p$ up to approximately 1.3 were obtained, and no equilibrium or gross stability limits were observed.