Recent Progress of Boundary Plasma Research 4.Recent Progress of Boundary and Divertor Plasma Studies in Helical Devices

Abstract

Edge magnetic structures in helical devices are complicated in comparison with those in poloidal divertor tokamaks, resulting in edge transport properties unique to helical devices. The results of experimental observations and computer simulations of the Large Helical Device and Wendelstein7-AS are summarized ; they suggest that cross-field transport plays important role in reduction of plasma pressure along the field lines.