Development of 1 MW output power level gyrotrons for fusion systems

The paper presents the latest results of development in Russia of 1 MW power level gyrotrons for future fusion installations. These applications require a very long pulse of microwaves (10...1000 sec) or CW tube operation at frequencies 110...170 GHz. The distinctive features of modern gyrotrons, the main problems of elaborating powerful gyrotrons and highlights of gyrotron development in the last few years are discussed.