Observations of MARFEs and impurities in the boundary layer of HL-1

Abstract We have observed MARFE and Detached Plasma (DP) impurity radiation by using a multichannel fibre-optical system mounted on the HL-1 tokamak to collect plasma light from the vicinity of the limiter. The space-time distribution of radiation and line emission indicate that the MARFE occurs on the inside midplane, with a poloidal extent of ~ 33°. In the DP state the plasma is detached by approximately 3.7 cm from the limiter.