Radial electric field in the biasing experiments and effective conductivity in a tokamak

The biasing experiments and the problem of the effective perpendicular conductivity in a tokamak are studied both analytically and numerically. The simulations were performed by means of the B2SOLPS5.0 transport code [V. A. Rozhansky , Nucl. Fusion 41, 387 (2001)] where the fluid set of equations is solved for the real divertor geometry. It is demonstrated that there exist three regimes, which correspond to the different values of the effective perpendicular conductivity and to different profiles of the radial electric field and toroidal and poloidal rotations. Simulation results are compared with existing and developed analytical models. (C) 2002 American Institute of Physics