Wavelet correlation between electrostatic and magnetic plasma oscillationsin the tokamak TBR

Wavelet spectrum and bispectrum techniques were applied to study nonstation ary turbulence at the plasma edge of the TBR tokamak. Evidence of nonlinear phase coupling is more significant for magnetic than for electrostatic flu ctuations. On a single discharge basis, the data also exhibit intermittent episodes of linear and nonlinear coupling between electrostatic and magneti c field oscillations. Furthermore, application of resonant perturbing magne tic fields reduces the amplitude of low frequency fluctuations and shift th e frequency range of the maximum quadratic intermittent coupling to larger scales. These alterations, observed not only for magnetic but also for elec trostatic oscillations, support the possibility of roughly altering electro static oscillations, therefore transport, through controlling oscillating m agnetic fields.