Manufacturing studies of structural components for the ITER EC upper launcher

Abstract

To counteract plasma instabilities, electron cyclotron launchers will be installed in four of the ITER upper ports. An EC launcher consists of a structural system which accommodates the MM-wave-components and has to meet demands on precise alignment, sufficient removal of nuclear heat loads, mechanical strength and proper nuclear shielding. The structural system consists of the Blanket Shield Module (BSM) and the Mainframe. Depending on the expected heat loads, the launcher components are designed as double-wall or single-wall elements, connected by massive flanges. Double-wall segments feature narrow cooling gaps with stiffening ribs between stainless steel shells. Single-wall segments consist of welded stainless steel plates with substantial material thickness. To investigate industrial manufacturing routes, characteristic sections of the BSM and the Mainframe were addressed in detail. To identify the optimum manufacturing strategy for double-wall components, three different concepts, namely HIP (Hot Isostatic Pressing), brazing and machining were studied and a total of four mock-ups of double-wall components were produced. Also for single-wall components appropriate manufacturing routes were investigated, optimum production parameters were determined and typical segments were manufactured. These prototypes are under study at the FZK Launcher Handling Test facility (LHT) where various ITER operating conditions can be simulated. Analyses and test series related to feasibility, prevention of residual stresses, contour accuracy, thermo-hydraulic behavior and also economical aspects were performed.