Density Reconstruction Using a Multi-Channel Far-Infrared Laser Interferometer and Particle Transport Study of a Pellet-Injected Plasma on the LHD

Abstract

Radial density profiles are obtained by applying the database slice and stuck density reconstruction technique to measured line-integrated densities, using multi-channel far-infrared laser interferometer installed on the Large Helical Device (LHD). A novel method that considers flux surfaces in the reconstruction process has been developed and applied successfully to a pellet-injected discharge in the LHD, enabling the identification of transient density peaking due to an inward pinch and enhanced diffusion in the edge region. The relationship between the change in particle transport and measured turbulence information obtained using reflectometry was also studied.