Particle control in long-pulse discharge using divertor pumping in LHD

Abstract Density control is crucial for maintaining stable confined plasma. Divertor pumping, where neutral particles are compressed and exhausted in the divertor region, was developed this task Large Helical Device. In study, particle pressure, which related to recycling, systematically scanned magnetic configuration by changing axis position. High pressure compression were obtained a high plasma electron density inner configuration. using pumping with gas puffing applied cyclotron heated configuration, provides exhaust divertor. Stable temperature maintained pumping. A heat analysis shows that did not affect edge conductivity, but it led low conductivity core caused electron-internal-transport-barrier-like formation.