The design of the EC Upper Launcher and Ex-vessel waveguide systems for ITER

The EC Upper Launcher (UL) and Ex-vessel waveguide (EW) are integral components of the ITER Electron Cyclotron (EC) system [1], which plays a key role in achieving and maintaining the high temperatures required for nuclear fusion within the tokamak, providing plasma heating and current drive, and magnetohydrodynamics (MHD) stabilization, which are crucial for ITER’s operational success. The EC system is increasingly becoming the reference mechanism for plasma heating in both present and future devices. Notably, ITER is placing significant reliance on the EC system, with the recent re-baseline proposal initially doubling the EC installed power from 24 MW to 48 MW, ultimately reaching a final configuration of up to 80 MW. The F4E contribution to the current ITER baseline configuration comprises four Upper Launchers and five sets of ex-vessel waveguides. The UL and EW systems, currently in its Final Design phase under the frame of a Procurement Agreement between Europe and ITER Organization, have released the Final Design Documentation Package, which is here described, as input to the Final Design Gate Review that took place in July 2025. The full set of documents released is composed by: 1) a Design Description Dossier composed by a UL & EW Design Description (DD) document and supported by a set of 3D models, drawings and diagrams; 2) a Design Justification Dossier encompassing a set of end-to-end engineering analyses verifying the functionality and structural integrity of the components according to the applicable requirements, and the RAMI analysis of both systems; and 3) a Product lifecycle Dossier covering documentation for subsequent phases including manufacturing, assembly, installation, commissioning, operations, maintenance and decommissioning. Furthermore, the validation of the design is supported by currently on-going activities of prototyping and testing of the most critical components.