The Edge Fluctuations in H-mode Like Discharges Induced by Electrode Biasing on the HL-1 Tokamak

H-mode like discharges have been achieved by electrode biasing on the HL-1 tokamak. During the biasing period, the energy confinement time tau(E) increased and density fluctuations were suppressed. It is shown that the fluctuation spectrum with biasing is very different from the unbiased case. The auto-power spectrum value of the density fluctuation decreased, and the fluctuation power had a different value as a function of the biased voltage variation.