CORRELATION BETWEEN PLASMA EDGE ELECTROSTATIC AND MAGNETIC OSCILLATIONS IN THE BRAZILIAN TOKAMAK TBR

Measurements of poloidal and radial magnetic field, density, potential , and temperature fluctuations were simultaneously performed at the pl asma edge of the TBR tokamak using a especially constructed probe syst em. Direct cross spectral and bispectral analyses of these fluctuation s showed evidences of both linear and nonlinear coupling between elect rostatic and magnetic oscillations. Resonances created by external per turbing magnetic fields slightly reduced the linear coupling and almos t entirely suppressed the quadratic coupling.