Development of high power klystron for JT-60 radio frequency plasma heating system

As one of the second stage heating methods for the critical plasma testing facilities JT-60, the construction of a radio frequency heating system is in progress. The development of a high power klystron which is the main component of the heating system has been carried out since 1980, therefore, its features, testing setup, evaluation test and so on are reported. The development has already been completed, and at present, the manufacture and test of a klystron for the actual heating system are in progress. The radio frequency heating system is composed of a high power exciting and amplifying part, the waveguide and other transmission system leading the excited and amplified RF waves to the tokamak, the coupling system of a special antenna and others. In Japan Atomic Energy Research Institute, a LHRF heating system and an ICRF heating system have been constructed as the RF heating system for the JT-60 tokamak, and the development of the high power klystron has been carried out for the construction of the LHRF heating system. The trial manufacture and development and the features of the high power klystron and its test are described. (Kako, I.)