Author/Authors :
Tamai، نويسنده , , H. and Konoshima، نويسنده , , S. and Hosogane، نويسنده , , N. and Asakura، نويسنده , , N. and Sakata، نويسنده , , S. and Saito، نويسنده , , N. and Akiba، نويسنده , , K. and Akasaka، نويسنده , , H. and Kawamata، نويسنده , , Y. and Kurihara، نويسنده , , K.، نويسنده ,
Abstract :
The sustainment of radiative divertor plasma in JT-60U is performed by the feedback control of the gas puffing rate into the divertor region with an actuator of the divertor radiation power. The feedback control system switches the piezoelectric gas valve every 10 ms, so that the proper amount of gas flux is fed for divertor radiation power to follow the reference waveform. The divertor radiation of 6 MW, which is about 40% of the heating power, is sustained for about 3 s by the hydrogen gas puffing with feedback control. The present logic of the feedback system, however, is not sufficient to fully control the divertor radiation which is modified by the change in heatings and plasma parameters. In order to prevent the loss of control, multi actuators for the feedback control, for example, the involvement of the heating power, and the selection of observed bolometer channels may be required.
