Present status of BA DEMO design activity

Tobita, Kenji; Nishio, Satoshi; Nishitani, Takeo; Ozeki, Takahisa; Araki, Masanori; Okano, Kunihiko*; Hiwatari, Ryoji*; Ogawa, Yuichi*

During the first three years of BA DEMO design activity, exchange of opinions is carried out between Japanese and European experts in a workshop style. In the previous two workshops, the both parties were devoted to discussions on definition of DEMO, role of DEMO in their fusion development program, requirements for DEMO and issues on DEMO physics and engineering. Throughout the discussion, common design issues which are not independent DEMO design concepts, including (1) divertor, (2) maintenance, (3) superconducting magnet, (4)current drive (steady state operation), etc. Key issues regarding each subject are removal of high heat load in the divertor under severe neutron environment, maintenance scheme which could provide high availability, need for high field superconducting magnet, and current drive schemes favorable in the aspects of the current drive efficiency and the controllability of current profile.