Author/Authors :
Ikeda، نويسنده , , Y. and Akino، نويسنده , , N. and Ebisawa، نويسنده , , N. and Hanada، نويسنده , , M. and Inoue، نويسنده , , T. and Honda، نويسنده , , A. and Kamada، نويسنده , , M. and Kawai، نويسنده , , M. and Kazawa، نويسنده , , M. and Kikuchi، نويسنده , , K. and Kikuchi، نويسنده , , M. and Komata، نويسنده , , M. and Matsukawa، نويسنده , , M. and Mogaki، نويسنده , , K. and Noto، نويسنده , , K. and Okano، نويسنده , , F. and Ohga، نويسنده , , T. and Oshima، نويسنده , , K. and Takenouchi، نويسنده , , T. and Tamai، نويسنده , , H. and Tanai، نويسنده , , Y. and Umeda، نويسنده , , N. and Usui، نويسنده , , K. and Watanabe، نويسنده , , K. and Yamazaki، نويسنده , , H.، نويسنده ,
Abstract :
Modification of JT-60U to a superconducting device (so called JT-60SA) has been planned to contribute to ITER and DEMO. The NBI system is required to inject D0 beams of 34 MW for 100 s. The upgraded NBI system for JT-60SA consists of 12 positive-ion-based NBI (P-NBI) units and one negative-ion-based NBI (N-NBI) unit. The injection powers of each P-NBI and N-NBI units are 2 MW at 85 keV and 10 MW at 500 keV, respectively. On JT-60U, the long pulse operations of 30 s at 2 MW and 20 s at 3.2 MW have been achieved on the P-NBI and N-NBI units, respectively. Both units have demonstrated no injection power degradation for long pulse operation. It has been also found that the thermal time constants of the main key components with active cooling, such as the ion source of the present NBI system, are less than ∼20 s. Therefore, the pulse extension up to 100 s is expected to need some modifications mainly the power supply system. In addition, the voltage-holding capability of the negative ion source is required to be improved. The detailed technical design of the NBI system for JT-60SA is presented.
