An overview of the JT-60 project

The Japan Atomic Energy Research Institute has recently completed the construction of the large tokamak JT-60, which constitutes a focus of the Second Phase of the Japanese fusion development program under the Atomic Energy Commission started in 1975. Initial experiments on JT-60 were carried out starting in April 1985. The objective of the JT-60 project is to investigate plasma confinement and heating in reactor-grade hydrogen plasmas and to conduct an integrated test of associated fusion technologies. JT-60 has a long-pulse capability of 5-10 s in pulse length and features, among others, a magnetic limiter (divertor), various methods of supplementary heating, and current drive by RF waves. Development of heating devices has been successful, and full installation and testing of the heating devices will be completed by July 1986. The present paper describes the objectives, design features, summary of construction and development, and the experimental program of JT-60. Some results obtained from initial plasma operation are also briefly described. (orig.)