Author/Authors :
Kasugai، نويسنده , , Atsushi and Sakamoto، نويسنده , , Keishi and Takahashi، نويسنده , , Koji and Kajiwara، نويسنده , , Ken and Shoyama، نويسنده , , Hiroaki and Ikeda، نويسنده , , Yukiharu and Tsuneoka، نويسنده , , Masaki and Ikeda، نويسنده , , Yoshitaka and Fujii، نويسنده , , Tsuneyuki and Kariya، نويسنده , , Tsuyoshi and Mitsunaka، نويسنده , , Yoshika and Imai، نويسنده , , Tsuyoshi، نويسنده ,
Abstract :
A 110 GHz-Gaussian beam output gyrotron with chemical vapor deposition (CVD) diamond window was developed for electron cyclotron heating and current drive on JT-60U. A stable Gaussian output beam power of 1.0 MW for 2 s was obtained with depressed collector operation. The temperature at the center of the diamond window was stabilized at the ΔT∼25 K. Gaussian beam output from the gyrotron remarkably improved the coupling efficiency to the HE11 mode in the transmission waveguide. 94% of the gyrotron output power was coupled to the corrugated waveguide of 31.75 mm in diameter, via a matching optics unit with two mirrors. A combination of the Gaussian output and the diamond window are indispensable for high power gyrotron operation at more than 1 MW and efficient coupling to the transmission line.
