European negative ion based neutral beam developments

The European negative ion based neutral beam development programme mainly consists of experiments on high energy accelerators and high current D-sources conducted at CEA Cadarache. A 1 MeV, 0.1 A D- acceleration experiment will start operation beginning of 1995. This experiment will test SINGAP, a highly simplified negative ion electrostatic accelerator concept. During the preparatory phase of SINGAP, a source has been developed which produced, with Cs seeding, D- beams of more than 1 A and 0.6 A D- beams with jacc > 12 mA/cm2. A new pre-accelerator has also been designed which traps nearly 100% of the extracted stray electrons; this was made possible by the development of the new 3-D Monte Carlo code ELSTOP, which simulates the electronic trajectories. In parallel, a new source test bed, MANTIS, was built and started operation during summer 1993. Up to now MANTIS has tested a source designed at AEA Culham for the former DRAGON experiment; operated without Cs seeding, this source produced 1.3 A H- and 0.5 A D- beams. Collaborations with European laboratories, AEA Culham, Ecole polytechnique Palaiseau and Dublin City University are under way, with the aim of improving the understanding of the negative ion production and of developing a multiampere D- source during 1995. (author). 11 refs, 3 figs