In this talk, we will describe in detail the consequences on the negative ion kinetics of the asymmetry in the plasma parameters perpendicular to the magnetic field direction (due to the plasma polarization induced by the Hall current intercepted by the ion source wall). This work is relevant to negative ion sources with a magnetic filter field producing an electron drift directed toward one...
It is essential to generate the negative ion beams with good beam optics for the negative ion sources. Negative ion beam optics is determined by the shape of the plasma meniscus, which is an ion emitting surface. However, for the electronegative plasma including the surface produced H- ions in the negative ion sources, the key parameters to control the plasma meniscus and the dependence on...
Dynamic responses of negative ion meniscus to externally applied RF field with 2% arc discharge power were investigated experimentally. Three types of responses were identified. First is the beamlet width oscillation with the same frequency as the applied RF field. The second is the oscillation of the beamlet axis. The third is the response of the time-averaged beamlet width. These responses...
The BATMAN Upgrade (BUG) test facility at IPP is contributing to the development of RF-driven H$^–$ sources towards the ITER neutral beam injection and beyond. BUG is equipped with an 1/8 size of the ITER NBI ion source and thus is highly flexible for setup changes or diagnostic access. The extraction and acceleration system consists of three grids (plasma grid PG, extraction grid EG and...
