Engineering Studies on the EAST Tungsten Divertor

Experimental advanced superconducting tokamak device is a D-shaped full superconducting tokamak with actively water cooled plasma facing components. To achieve long pulse and high βH-mode plasma, new plasma position and shape are calculated and optimized during the campaign of 2013-2014. New divertors are designed and developed to fit the plasma and endure the heat flux up to 10 MW/m². The divertor is International Thermonuclear Experimental Reactor-like. It bases on monoblock and cassette technology and is composed of plasma facing component (PFC) units, cassettes, and support systems. Monoblock structures are just employed on the PFC units of target plates of the divertors, thus W flat tiles are used on the baffles and dome. At the end of monoblocks, end boxes are applied. Cassettes act not only as the supports of the PFC units, but also as manifolds for the cooling channels of the units. The support systems consist of inner support rails, outer support rails, and auxiliary braces. The support systems are installed on the vacuum vessel before cassettes are put on. To dock the cassette with the support system, it is just lifted and pushed forward. To verify and optimize the structure, Research and Development work has carried out for the divertor. The prototypes of PFC units and cassettes are fabricated with different manufacture processes. The total assembly process is also simulated with these prototypes on mockup facility and the vacuum vessel. The results show that the divertor system can be manufactured successfully according to the requirements of drawings and installed conveniently and precisely on the tokamak. All these works certify that the design of the divertor is all right. The batch production of the divertors can be started.