Comparative studies of inner and outer divertor discharges and a fueling study in QUEST
Autor: | S. Kawasaki, K. Matsuoka, Hiroshi Idei, Hiroaki Tsutsui, Osamu Mitarai, Takumi Onchi, Kazuaki Hanada, Katsumasa Nakamura, Makoto Hasegawa, S. Koike, Akihide Fujisawa, A. Higashijima, Hideki Zushi, Toshiki Takahashi, H. Nakashima |
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Jazyk: | angličtina |
Rok vydání: | 2016 |
Předmět: |
010302 applied physics
Physics Mechanical Engineering Divertor Solenoid Mechanics Plasma Spherical tokamak 01 natural sciences 010305 fluids & plasmas Inductance Nuclear Energy and Engineering Electromagnetic coil 0103 physical sciences General Materials Science Current (fluid) Atomic physics Coaxial Civil and Structural Engineering |
Zdroj: | Fusion Engineering and Design. :1365-1370 |
Popis: | As QUEST has a small central solenoid (CS), a larger Ohmic discharge current has been obtained when the plasma shifts to the inboard side. This tendency restricts a divertor operation to the smaller plasma current regime. As the inner divertor coil has a smaller mutual inductance, it would be expected that its utilization seems to be better for easier plasma current ramp-up for a divertor operation. In this work, we made comparative studies on the plasma current ramp-up for two divertor coils. It is found that while the inner divertor coil with smaller mutual inductance needs a larger coil current, the outer divertor coil with larger mutual inductance needs a smaller coil current for divertor operation. Thus we have found that the plasma current ramp-up characteristics are almost similar for both configurations. We also propose a new fueling method for spherical tokamak (ST) using the coaxial helicity injection (CHI). The main plasma current would be generated at first, and then the CHI plasma current is created between bottom two electrode plates and merged into the main plasma current for fueling. |
Databáze: | OpenAIRE |
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