FEM Simulation of ITER EC H&CD Diamond Microwave Window Unit during Preparation and Subsequent Service

The microwave window unit is the core component of the electron cyclotron heating and current drive (EC H&CD) system used in fusion reactors. In this work, a diamond disk for the microwave window was designed according to the electromagnetic propagation theory. Then, the finite element method was employed to build a microwave window model based on our tailored dimension. The effect of brazing and subsequent service processes on the stress/strain distributions and electrical parameters were explored. Overall, the microwave window exhibited excellent performance, with the maximum principal stress of the brazed disk under service being 51 MPa, which was much lower than the allowable stress of diamond. It was also indicated that the electrical properties barely changed, which could satisfy functional requirements. This work provided theoretical guidance for the design and manufacture of diamond microwave windows used in fusion reactors.