Accessibility to a Double-Peaked Er Shear Layer Structure by Double Electrode Biasing in Tokamak Plasmas

Bifurcation of the radial electric field in the tokamak edge, which is induced by electrode biasing, is studied. A case of multiple electrodes is investigated in order to obtain a structure of multiple peaks in the radial electric field. It is found that a double-peaked structure is accessible with an applied voltage rampup, allowing the possibility of obtaining double transport barriers.