The European 2MW, 170GHz Coaxial Cavity Gyrotron for ITER

Abstract—In the reference ECH design, ITER requires a total of 20MW/CW power at 170GHz using gyrotrons with a unit power of 1MW. A higher power per unit (2MW/gyrotron) would result in a strong reduction of the cost of the whole ECRH system, and would also relax the room constraints on the launcher antenna design. The high power capability of coaxial cavity gyrotrons has been demonstrated with short pulse experiments at FZK. A collaborative effort between European research associations CRPP-EPFL, FZK and Thales Electron Devices (TED) has been launched by the European Fusion Development Agreement (EFDA) in 2003, aiming at the development of an industrial 170GHz/2MW/CW coaxial cavity gyrotron. The first prototype, although designed to be CW compatible is expected to reach 2MW/1s and has been delivered by end of 2006. It will be tested in Lausanne, where a specially dedicated test facility has been built. The test facility has been designed to be flexible enough, allowing the possible commissioning of tubes with different characteristics, as well the tests of the launcher antenna at full performances. Initial experiments are planned for the end of the third quarter 2007. Index Terms—Coaxial cavity gyrotron, ITER I