Final design of the High Voltage Deck 1 and Bushing for MITICA: The ITER Heating Neutral Beam Injector prototype

•HVD1 and HVBA are unique devices for size, electrostatic and mechanical features.•Main design choices to satisfy the challenging technical requirements are presented.•The supporting electrostatic, seismic and thermal analyses are reported.•Next procurement steps and tests to verify the key design choices are also reported.