Impurity control in Fusion Experimental Reactor (FER)

Poloidal divertor system is employed as the impurity control measure in Fusion Experimental Reactor (FER). The authors will report the overall survey of impurity control physics in FER. The results obtained are as follows. (1) The triple-valued solutions of divertor plasma equilibrium are obtained as a function of incoming ion flux. Engineering design is carried out based on the stable dense and cold divertor plasma. (2) Low density and high temperature solution disappears when the geometry is extremely closed (chamber length=50cm and void width=O). (3) Plasma temperature can become slightly high on the side of exhaust duct near the plate. (4) Erosion rate on the first wall by charge-exchange neutrals is recognized to be about 1cm/year by DEGAS code that is also obtained by even our divertor code and simple order estimation. (5) Cold and dense divertor plasma could be formed during noninductive current drive phase either LHRF or NBI, if the current drive efficiency is improved