The alternative design concept for the ion source power supply of the ITER neutral beam injector

The paper reports a comprehensive overview of the power supply (PS) systems of the neutral beam (NB) injectors of the main fusion experiments in view of introducing an alternative concept, with respect to the reference design, for the power supplies feeding the ion source of the international thermonuclear experimental reactor (ITER) NB injector. The overview is proposed to understand the evolution of the systems, analyze the motivations behind the design choices and highlight how they were often the results of a compromise between contrasting requirements. The approach adopted in the PS reference design of the ITER NB injector is described and the results, in particular in terms of feasibility of some devices and accessibility issues, are discussed. The second part of the paper is dedicated to the description of the alternative concept for the ion source power supply (ISPS) design; the solution proposed is discussed with the aim of evaluating and comparing the different implications with respect to the reference design.