The Upgrade of EAST Divertor

Abstract

The scientific and the engineering missions of EAST are to explore the reactor related regimes with long pulse lengths and high plasma core confinement and solutions for power exhaust and particle control under steady state operation and to establish technology basis of full superconducting tokamaks. EAST can operate with double null or single null divertor mode. The goals of the divertor are to get high parameters plasma, long pulse operation and single or double null plasma shape. So the divertor is designed as up-down symmetry structure to provide large experimental flexibility. The divertor should have the capacity to endure higher heat flux and provide recycling and impurity control. Up to now, three generations divertors which are steel, carbon and tungsten divertor respectively have been developed and installed on EAST. The steel divertor is just used in the commissioning test of the host machine in 2006. The carbon divertor which is composed of graphite tiles, CuCrZr heat sink and stainless steel supports is commissioned to endure thermal load of no more than 4 MW/m2 in 2008. Thus the tungsten divertor which is based upon cassette and mono-block technology like ITER is expected to endure the heat flux up to 10 MW/m2 in 2014.