2024.12.09

位相空間乱流ユニットのセミナーを開催いたしました。
　

【 日　時 】　2024年12月6日（金）

【 場　所 】 オンライン開催

【 話し手 】　Mei Huang（Southwestern Institute of Physics, China）

【 題　目 】　Development and Preliminary Heating Experiments of Electron Cyclotron Resonance Heating and Current Drive System on HL-3 Tokamak

【Abstract】　

For the HL-3 tokamak, Electron Cyclotron Resonance Heating and Current Drive (ECRH/ECCD) system will be acted as one of the key plasma heating methods for central electron heating, current profile control and NTM suppression. A preliminary design of 8 MW ECRH/ECCD system for HL-3 tokamak has been conducted and finished in 2016. Key components of this system have been designed, manufactured and tested since then. At the end of 2022, a 5.5 MW ECRH system has been developed on HL-3 tokamak for half a year installation, which consists four 105 GHz/1 MW/3 s, one 140 GHz/1 MW/3 s and one 68 GHz/0.5 MW/1.5 s subsystems. The high-power microwaves are produced by six GYCOM 1 MW or 500 kW gyrotrons, transported by five F63.5 mm evacuated and one F80 mm un-evacuated over-mode corrugated transmission lines (TLs) and injected into plasma by three fast steerable launchers. All gyrotrons are settled in the RF heating hall which is in the south of HL-3 tokamak hall. The consideration of TLs routing and TLs installation was mainly focused on getting the best solutions of attenuation issues. The mode purity could be reached about 94 % which was analyzed by phase retrieval method through testing the power distribution by thermal imager and the transmission efficiency is about 92 % for ~40 m TLs. For the three launchers, the 4 MW mid-plane, 2 MW 1# upper launchers and 1 MW 2# upper launcher have been installed on HL-3. In the poloidal direction, more complicated push rod framework for three launchers was employed for NTM suppression in real time. The total response time of control activities is less than 100 ms and the dynamic response time of mechanism for the full scan range is less than 200 ms in the poloidal direction for full scan range. Commissioning half a year, in July 2023 maximum 1.8 MW output power was injected into plasma. The power was deposited at the high field side and plasma heating effect was significant at the range of 1.5-1.7 T toroidal field. With 800 kW ECRH, the storage energy was increased about 50 % when the plasma current is 500 kA and toroidal field is 1.69 T. With 1.2 MW NBI, 0.3 MW LHCD and 1 MW ECRH, high confinement mode discharge was achieved when the plasma current is 1MA and toroidal field is 1.59 T. In the middle of 2026, the ECRH system will be upgraded to 11 MW, including 5 MW/105 GHz/3s, 2 MW/140 GHz/3 s and 4 MW/140 GHz/175 GHz/10 s subsystems for more advanced physical experiments.

【 問い合わせ 】　

西浦正樹：nishiura@nifs.ac.jp