History of controlled nuclear fusion in Japan

A research development of nuclear fusion was divided four periods: the first period as prehistory (until about 1955), the second period as begin of research (1955 to 1969), the third as the growth period (1970 to 1985) and the forth as the large tokamak age. In this paper I explained the second period, because general physicists and young plasma and controlled nuclear fusion researcher did not know about this period. The controlled nuclear fusion research was begun by the experiment of hydrogen bomb by USA and USSR in 1952 and 1953. In Japan, on the basis of many societies, 'The Controlled Nuclear Fusion Meeting' was established as an independent system and KAKEA (Journal of Fusion Research) was published in 1958. Japan government began to make the system by the Nuclear Commission in 1957. The main research devices in 1962 were linear pinch, mirror device, toroidal pinch, helical system, plasma gun and plasma measurement. USSR showed the excellent results of tokamak device in 1968. Ookawa spoke the effect of the average minimum-B, the best report in this period, at the second IAEA meeting, 1965. JAERI constructed JFT-1 and JFT-2, the latter was the first class device in the world and made the first step of Japanese research into the world, for examples, to attain the equilibrium of divertor plasma and to control impurity. Many research centers of controlled fusion were established in many universities in Japan from 1966 to 1980. Cooperation researchs between Japan and USA, USSR and many countries has been carried out after 1978: JIFT (Joint Institute for Fusion Theory) and FPPC (Fusion Power Coordinating Committee). The important results increased in this period. After 1985, the research activities are processing and data increased very fast depend on the larger devices and system, good measurement system and development of information system. JT-60 in JAERI opened to the large tokamak period. It led controlled fusion researchs in the world the same as TFTR (US) and JET. Many times need for collection and analysis of these data. LHD (Large Helical Device) made succeed the first ignition, 1998. The good helical device and mirror type device are constructed and made effects on researches among the nations. (S.Y.)