Effects of biasing on current drive and estimation of the parallel extent of the biasing current in the HL-3 tokamak

A wall mounted biasing plates system by eight biasing plates distributed toroidally on the upper first wall is applied to the HL-3 tokamak. Plasma configuration has a significant impact on the amplitude of bias-driven current. We also find that bias-driven current will affect the parameters in the scrape-off layer (SOL). It is also found that changes in magnetic fluctuations measured by the Mirnov probe are consistent with the spatial distribution of the bias-driven current. This indicates that the biasing plate system can drive the SOL current filament in HL-3 and provide the possibility of edge localized mode control.