Biased limiter experiment in the Heliotron E device

The first biased limiter experiment has been done in Heliotron E, which is a typical stellarator/heliotron type device. This experiment investigates the boundary physics of the currentless plasmas, which are produced in the magnetic limiter (divertor) configuration. We analyze the experimental results related to the surface potential, recycling process, and plasma parameters using a material limiter which was biased from the vacuum chamber. The boundary density profile was measured by a thermal Li beam probe to investigate the effect of the biased limiter. (orig.)