CW gyrotrons and gyrotron systems for applications in technology

Over the last decade high power millimeter-wave (MM-wave) sources have become firmly established as an advanced instrument for the development of innovative applications. The first 10 kW CW 30 GHz gyrotron system specifically designed for research into MM-wave processing of materials was pioneered by the Institute of Applied Physics (Russia) in 1993. The advent of gyrotron systems in the area of applications commonly occupied by 2.45 GHz magnetrons owes mainly to two circumstances. In early 90s it became clear that the exploiting of MM-wave radiation enhances considerably the potential of applications in which the microwave energy can be beneficially used. The major advantages associated with the use of MM-wave radiation in processes based on volumetric heating of materials have been widely discussed. A marked increase in the efficiency of heating of low loss materials, and the possibility to heat uniformly large size specimens are of greater practical importance among others factors. On the other hand, the experience acquired in the development of the megawatt-level gyrotrons for fusion was so wide in the 90s that it was not unduly difficult to design a MM-wave source of moderate CW power adapted for use in material science research and other applications. The general design of the 10 kW 30 GHz system provided a basis for further development of gyrotron MM-wave sources for applications. Although devices operating at different frequencies and power level may vary in details, the overall structural approach remains common to all of them. At present, the CW gyrotrons produced by GYCOM for applications in technology cover the 24-83 GHz frequency range and vary from 3-30 kW in power.