Progress in development and design of the neutral beam injector for JT-60SA

Neutral beam (NB) injectors for JT-60 Super Advanced (JT-60SA) have been designed and developed. Twelve positive-ion-based and one negative-ion-based NB injectors are allocated to inject 30 MW D-0 beams in total for 100s. Each of the positive-ion-based NB injector is designed to inject 1.7 MW for 100s at 85 key. A part of the power supplies and magnetic shield utilized on JT-60U are upgraded and reused on JT-60SA. To realize the negative-ion-based NB injector for JT-60SA where the injection of 500 key, 10 MW D-0 beams for 1005 is required, R&Ds of the negative ion source have been carried out. High-energy negative ion beams of 490-500 key have been successfully produced at a beam current of 1-2.8 A through 20% of the total ion extraction area, by improving voltage holding capability of the ion source. This is the first demonstration of a high-current negative ion acceleration of >1 A to 500 key. The design of the power supplies and the beamline is also in progress. The procurement of the acceleration power supply starts in 2010. (C) 2011 Published by Elsevier B.V.