Development of a full-size divertor cassette prototype for ITER

Production of a full-size divertor cassette for the International Thermonuclear Experimental Reactor (ITER) involves eight major components. All of the components are mounted on the cassette body. Inner divertor channel components for both the vertical target and the gas box design are being provided by the Japan Home Team. Outer divertor channel components for the vertical target design are being provided by the European and United States Home Teams. Gas box liners are being provided by the Russian Home Team. The full-size components manufactured by the four parties will be shipped to the US Home Team for assembly into a full-size divertor cassette. The techniques for assembly and maintenance of the cassette will be demonstrated during this process. The assembled cassette will be tested for proper flow distribution and proof of the filling and draining procedures. The testing will include vacuum leak, cyclic heating to 150 degrees C, and verification of dimensional accuracy of the assembled components. The development of the divertor for ITER depends on successful R&D efforts on materials, joining and plasma-materials interactions. Results of the development program are presented. The scale-up of the processes developed in the basic R&D tasks is accomplished by producing medium and full-scale mock-ups and testing them at high heat flux. The design of these mock-ups is discussed.