Design of electrodes for high voltage tests in MITICA

The NBTF (Neutral Beam Test Facility) in Padova, Italy, is dedicated to testing and optimizing the Neutral Beam Injector for ITER. A full-scale prototype known as MITICA is currently being constructed at NBTF to demonstrate all the design parameters for ITER, including stable beam operation at 1MeV energy. To achieve stable high voltage holding of 1MV, a dedicated campaign is planned for 2023, which will utilize realistic mockups of the MITICA ion source and accelerator. During this campaign, the mockup of the ion source will be biased with an increasing potential up to -1MV, and the discharge towards the grounded electrodes will be observed. This will help identify any potential weak points in the geometry that can be mitigated. This work briefly describes the design process of the mock-up electrodes, including electrostatic and structural analyses. The construction of the electrodes has started in 2022 and the installation is foreseen for 2023.