Requirements specification for the Neutral Beam Injector on FAST

Abstract This paper discusses the scientific and technical requirements for a Neutral Beam Injection system on the FAST tokamak and describes a preliminary conceptual design of a suitable injector. FAST is being proposed as a European experiment in support to the operations on ITER and to the design of DEMO. The specific mission of this device is an integrated approach to a number of outstanding burning plasmas physics and operational issues with an emphasis on the impact of fast particles on turbulent transport. Such scientific requirements set a series of technical challenges regarding the injector and the coupling of the injector to the FAST main chamber that are addressed in the paper. A preliminary conceptual design of the injector is proposed which attempts to meet the stated requirements.