FEM analyses of the ITER EC H&CD torus diamond window unit towards the prototyping activity

Abstract

The chemical vapour deposition (CVD) diamond torus window unit is a sub-component of the ITER Electron Cyclotron Heating and Current Drive (EC H&CD) system used for a diverse range of applications including plasma heating and control of plasma magneto-hydrodynamic (MHD) instabilities. It consists of an ultra-low loss polycrystalline diamond disk brazed to copper cuffs and then enclosed by a metallic structure. The diamond disk with 1.11 mm thickness already passed successfully the ITER final design review (FDR) in 2018. In view of the complete window assembly FDR, prototyping activities of the window are essential and, therefore, they shall start soon in order to check the feasibility of the proposed manufacturing and assembling sequence of the component. In this perspective, as the design of the systems surrounding the window is currently in development phase, the paper describes the finite element method (FEM) analyses of the window to carry out with the aim to prove the soundness of the design used for the prototyping and also to define requirements for the surrounding systems. Specific methodologies are adopted such as the limit analysis approach for the external loads acting on the window unit. Several combinations of forces and moments are applied to the window unit to find the maximum loads, i.e. the limits loads, which generate stresses in the unit equal to the allowable ones, according to the selected design criteria.