The JT-60 machine upgrade and development towards the next step in Japan

Abstract

This paper describes an overview of three major magnetic fusion programmes in Japan. The first is the JT-60 machine upgrade (JT-60U) programme at Japan Atomic Energy Research Institute (JAERI). The large tokamak JT-60 is being modified in order to improve the plasma performance. The vacuum vessel and the poloidal field coils are replaced for large D-shape plasma productions. The main machine parameters of JT-60 upgrade are plasma current of 6 MA, plasma volume of 100 m 3. The second is the next step programme at JAERI. Design studies are being conducted of the Fusion Experimental Reactor (FER) as a domestic plan and of the International Thermonuclear Experimental Reactor (ITER) under the IAEA. The FER is a DT burning tokamak machine with a fusion power of approximately 400 MW and a 4.7-m major radius. This machine is to achieve adequate plasmas and reactor technologies prior to a Demo reactor. In parallel with the design studies, R&D works such as superconducting coils, negative ion beam and plasma facing component have been carried out. The third is the Large Helical Device (LHD) programme at National Institute for Fusion Science. The LHD programme is a major fusion programme of joint universities in Japan belonging to Ministry of Education, Science and Culture. This is the 7 years' programme, and the LHD is a Heliotron/Torsatron type helical device ( R = 4 m, B = 4 T) which contains 2 GJ superconducting helical coils.