Applications of new technology for production of high power millimeter waves to magnetic fusion research

Although research on magnetically confined fusion plasmas has been carried out for a half century, for most of this time control of the temperature, density and current density profiles has been limited and transient. Now, high power long pulse gyrotron systems with excellent reliability are coming on line, which can provide non-inductively driven currents and electron heating leading to higher plasma performance and continuous operation in reactor relevant regimes. The precision of the location at which heating and current drive are applied has also made it possible to suppress certain classes of plasma instabilities. Basic physics of electron cyclotron current drive and heating are understood and these new technological capabilities are being exploited in magnetic confinement devices worldwide.