ECRF systems for ITER

ITER, the International Thermonuclear Experimental Reactor, proposes to use electron cyclotron technology on an unprecedented scale. ECRF (electron cyclotron range of frequencies) will be used for start-up, heating, noninductive on-and off-axis current drive, and wall conditioning. Advanced gyrotron sources will be needed in order to fulfill the unique requirements imposed by these applications. Consequently, an international R&D program has been undertaken to develop 170 GHz, CW, 1 MW, /spl sim/50% efficient tubes. The rationale for the R&D program is presented and design issues relating to the efficient generation, transmission, and delivery to the plasma of over 50 MW of ECRF power are discussed.