Negative ion based neutral beam development at Cadarache

Most of the European activities in the field of negative ion based neutral beam development are conducted at Cadarache. This paper describes the 1 MV 0.1 A D^- multi-second beam acceleration project, which is scheduled to start at the end of 1994, results from the PAGODA ion source and preliminary results from the large volume source on the MANTIS testbed. The 1 MV experiment will test the simplified concept of beam accelerator SINGAP at relevant ion current densities and address several High Voltage issues. This will use a PAGODA source which has already produced, with caesium seeding, 1 A-60 keV transmitted D^- beam. At present, this source reliably produces 10 mA/cm² of D^- beam at 0.6 Pa as required for the 1 MV experiment. The main task of the MANTIS test bed is the development of a large area, multi-ampere D^- source which satisfies all the requirements of an injector, e.g. for ITER, MANTIS, which started operation in June this year has so far produced beams of approximately 1 A of H^- and 0.4 A of D^$