Conceptual design of the beamline for the DTT Neutral Beam Injector

The main purpose of the Divertor Tokamak Test facility (DTT) [1], whose construction is starting in Frascati,Italy, is to study solutions to mitigate the issue of power exhaust in conditions relevant for ITER and DEMO. DTTwill be equipped with a significant amount of auxiliary heating power (45 MW) to reach PS EP/R=15MWm-1required to be DEMO-relevant [2]. DDT is characterized by high flexibility for the assembling and testing ofdivertor components and for the different magnetic configurations to address the integrated physics and tech-nology problems. The conceptual design of the beamline for the DTT Neutral Beam Heating system is herepresented, with a particular focus on the technical solutions adopted to maximize the RAMI indexes (Reliability,Availability, Maintainability and Inspectability) and minimize complexity and costs. Various design options wereconsidered, and a comprehensive set of simulations was carried out using several physics and engineering codesto drive the choice of the most suitable design options and optimize them, aiming at finding a good compromiseamong different design requirements. This paper describes the design of the main components of the beamline,explaining the motivations for the main design choices.