The ITER diagnostic neutral beam (DNB) is to be used to diagnose He ash content of the ITER plasma during its DT operation phase using the CXRS diagnostic technique. The measurements shall be performed using a 100 keV 20 A neutral hydrogen beam. The measurements are performed at 21 m from the place where the beam is produced. It uses the step of ion beam production, acceleration, neutralization and charge separation to achieve the desired beam parameters.
The components and their manufacturing technologies are first of their kind. In order to ensure the goals delivered to the desired quality and standards extensive R&D efforts have resulted in development of several prototypes. The technologies involved include angled multi aperture grid segments with angular tolerance of 0.011o, deep hole drilling of ~ 2m with 500 micron drift, development of high heat flux CuCrZr and dissimilar metal welding using EBW. Beam development is being supported on single RF driven source test bed ROBIN. A unique facility with 21 m beam transport, INTF, is under development to produce and characterize DNB like beams.