Overview of manufacturing technologies under development in Russia for ITER plasma facing components

Abstract Manufacturing of the plasma-facing components (PFC) for the ITER is under qualification now (Merola et al., 2014) [ 1 ]. To start production of 179 first wall (FW) panels and 58 divertor domes (DD), for which the RF DA is responsible, it is necessary to manufacture their full-scale prototypes. In preparation for their manufacturing a wide range of technologies has been developed, which are continuously progressing (Mazul et al., 2011, 2012, 2016) [ [2] , [3] , [4] ]. Considering that changes were made in the DD design in view of the change-over to an all-tungsten divertor, as well as on the basis of the obtained results of manufacturing of the FW panel semi- prototype, the necessity arose to optimize some technological manufacturing stages. Thus, for the DD the composition of structural materials has been changed, the new assembly structure has been developed and analyzed; some technological operations have been optimized. The technological operations for FW panel have been also optimized, namely, the brazing temperature of the beryllium armor has been decreased, preparation works are under way on replacement of explosion welding by diffusion bonding for the steel-bronze joint. Most of the technological stages should be accompanied by non- destructive testing (ultrasonic, X-ray), the methods of which have been developed as well. The RF DA is also responsible for thermal testing of divertor elements. Due to application of the X-ray matrix the methods have been improved for recording of density of the applied heat flux produced by the electron beam. The ways for and the results of optimization of the technological and testing procedures are also presented below.