Revision and adaptation of the reference design HV bushing to SINGAP configuration

The 1 MV bushing of the ITER neutral beam (NB) injector is a HV feedthrough for all the electrical bus bars and the water cooling pipes of the ion source and of the accelerator. It acts also as a barrier between the SF₆ insulated HV line and the ITER primary vacuum. Two different accelerators have been considered for the ITER NB injector, namely the multiaperture multigrid (MAMuG) concept, which is now the reference design, and the single aperture single gap concept (SINGAP) as an alternative design. In this work the bushing reference design has been revised and adapted to the SINGAP option. The new design has been optimised by means of detailed electrostatic analyses. Mechanical analyses have been also carried out to assess the design of the bushing under the new loads in SINGAP configuration