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内容記述 |
The JT-60SA electron cyclotron (EC) system utilizes three frequencies: 138 GHz, 110 GHz, and 82 GHz, for plasma breakdown, heating, and current drive. During the first plasma operation campaign in 2023, plasma operation was performed using two EC systems, one with a single-frequency 110 GHz gyrotron and one with a triple-frequency gyrotron. From the next operation campaign, two more triple-frequency gyrotrons will be added, increasing the EC system to four systems. New high-voltage power supplies were procured from Europe for these new gyrotrons. These high-voltage power supplies consist of one main power supply and two sets of anode and body power supplies. Initial operation was conducted using the new triple-frequency gyrotrons, achieving simultaneous operations. Thus, four-system configuration has been completed, consisting of one new power supply and two existing power supplies. All four waveguide transmission lines are constructed with large-diameter waveguides with a diameter of 60.3 mm, with transmission distances of approximately 60 m or 110 m. The new two axis EC launchers consisting of two moving mirrors and one fixed mirror will be installed, enabling scanning at poloidal angles (-40° to +20°) and toroidal angles (-5° to +25°). Thus, the launchers will be connected to two transmission lines, making them possible to inject a total of more than 3 MW of power aiming at from the plasma center to the edge.For ITER EC system, QST has manufactured eight sets of 170 GHz/1 MW gyrotrons, completed factory acceptance tests, and shipped all of them to ITER. Assembly/installation works are currently underway inside ITER RF building, and two gyrotrons have been installed. One of the gyrotrons is currently being prepared for on-site acceptance test. ITER baseline has been upgraded, and the EC systems used for first plasma phase will be increased from the initial 24 systems to 48 systems. In future D-T operations, 80 systems will be utilized. QST will procure an additional 20 gyrotrons by the time of first plasma.Additionally, QST is conducting research activities using a multi-frequency gyrotron at 170 GHz, 203 GHz, and 236 GHz in preparation for a future DEMO. |
