Inward particle transport driven by biased endplate in a cylindrical magnetized plasma

Abstract

The inward particle transport is associated with the formation of peaked density profiles, which contributes to improve the fusion rate and the realization of steady-state discharge. The active control of inward particle transport is considered as one of the most critical issues of magnetic confinement fusion. Recently, it is realized preliminarily by adding a biased endplate in the Peking University Plasma Test (PPT) device. The results reveal that the inward particle flux increases with the bias voltage of the endplate. It is also found that the profile of radial electric field (E_r) shear is flattened by the increased bias voltage. Radial velocity fluctuations (V_r) affect the inward particle more than density fluctuations. And the frequency of the dominant mode driving inward particle flux increases with the biased voltage applied to the endplate. The experimental results in the PPT device provide a method to actively control the inward particle flux actively using a biased endplate and enrich the understanding of the relationship between E_r×B shear and turbulence transport.