Manufacturing and testing of large-scale mock-ups of ITER plasma facing components in Russia

Various ITER plasma facing components (PFC) are described, such as first wall (FW), start-up limiter and divertor vertical target (VT). Manufacturing and testing of large-scale mock-ups is the final stage on the long way of structure optimization and selection. of the most reliable and cheap manufacturing technologies. For the FW and limiter mock-ups fast brazing of Be tiles to CuCrZr heat-sink by brazing alloy STEMET-1101 was successfully applied. Testing of the FW large-scale mock-up up to 5000 cycles at 1 MW/m(2) did not reveal any damages of Be-Cu joints. For CuCrZr-SS bimetallic heat-sink/support structure two alternative joining technologies (HIP-for the limiter mock-up and CuCrZr casting onto solid SS-for the FW mock-up) were used. For divertor target mock-up the following technologies were used: pure Cu casting onto W tiles; fast brazing of W-Cu bimetallic tiles onto CuCrZr heat-sink; explosion bonding and CuCrZr casting as two alternatives for manufacturing of hermetic CuCrZr-SS structure of hypervapotron type; laser welding for attachment of heat-sink elements to support plate (SS-SS welds). Results of thermocycling testing of all mock-ups at operational heat loads are presented. Recommendations for futher improvement and characterization of above-mentioned technologies for ITER application are given. (C) 2002 Elsevier Science B.V. All rights reserved.