Generation of poloidal electric field with electron cyclotron resonance heating and its effects on particle confinement in Heliotron-E

The potential formation near the edge, X-points, and on the divertor footprints are studied using Langmuir probe arrays with respect to the density pump-out due to ECRH. It is found that a poloidal electric field is generated in the interior region, and this is considered to cause the enhanced particle flux across the LCFS. A poloidal structure of the edge potential distribution seems to be an m = 2 type and is discussed based on the orbit topology of warm electrons in the l = 2 heliotron configuration.