EUROPEAN NEGATIVE-ION BASED NEUTRAL BEAM DEVELOPMENTS

The European negative ion based neutral beam development programme con sists presently of experiments on high energy electrostatic accelerato rs and high current D- sources, and of neutral beam physics and system design studies. At CEA-Cadarache the source test bed MANTIS started o peration last June, and the 1 MV, 0.1 A, D- acceleration project SINGA P will be operational by the end of 1994. Additionally, negative ion s ource physics-oriented experiments will be conducted at Dublin City Un iversity. A Pagoda source, developed for the SINGAP experiment, recent ly produced more than 1 A D- beams and j(D-) of 10 mA cm(-2), with Cs seeding, at 0.6 Pa operating pressure. 1.3 A H- and 0.5 A D- beams hav e also been obtained without the use of Cs during the first experiment s on MANTIS. Studies on neutral beam heating (NBH) for a next step mac hine have been conducted during 1993, mainly at JET and CEA-Cadarache. NBH physics studies based on the RLW model indicate that ignition on ITER-EDA should be reached with about 40 MW of 0.4-1 MeV D-0 beams. Th e outlines of an NBH system for ITER-EDA, based on SINGAP, have been s tudied.