Thermal Hydraulic and Mechanical Assessment of the DTT ICRH Antenna

In the framework of the DEMOnstration power plant (DEMO) fusion-oriented activities and experiments, the Divertor Tokamak Test (DTT) facility has a prominent role due to the complexity of the technological and physical aspects to be investigated, and the remarkable amount of additional power (45 MW) for its plasma volume (34 m3). The DTT project will face one of the main challenges to be solved for the accomplishment of the EU Fusion Roadmap that foresees the realization of the DEMO plant: the high heat loads on the divertor. For this reason, the experimental reactor will be operated in scrape-off layer conditions close to ITER (International Thermonuclear Experimental Reactor) and DEMO, which pose significant challenges in the design of its plasma-facing components. One of them is the Ion Cyclotron Resonance Heating (ICRH) antenna, i.e., the most critical component of additional heating systems based on radiofrequency waves, which will face unprecedented heat load conditions compared to existing machines. The present paper describes the analytical and numerical activities performed to support the design of the DTT three-strap ICRH antenna. The aim of these activities is to assess the thermal loads on the components, design an appropriate cooling loop inside the most critical parts and numerically optimize the layout thanks to appropriate Computational Fluid Dynamics (CFD) simulations. Moreover, thermomechanical analyses of the most critical component was performed, to assess both the mechanical stresses and deformations and ensure its nominal performance during tokamak operation.