Comparative studies of inner and outer divertor discharges and a fueling study in QUEST

QUEST group

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

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.

Original languageEnglish
Pages (from-to)1365-1370
Number of pages6
JournalFusion Engineering and Design
Volume109-111
DOIs
Publication statusPublished - Jan 1 2016

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Fueling
Plasmas
Inductance
Solenoids
Electrodes

All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Nuclear Energy and Engineering
  • Materials Science(all)
  • Mechanical Engineering

Cite this

Comparative studies of inner and outer divertor discharges and a fueling study in QUEST. / QUEST group.

In: Fusion Engineering and Design, Vol. 109-111, 01.01.2016, p. 1365-1370.

Research output: Contribution to journalArticle

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AU - Idei, Hiroshi

AU - fujisawa, akihide

AU - Hanada, Kazuaki

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AU - Higashijima, A.

AU - Nakashima, H.

AU - Kawasaki, S.

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AU - Takahashi, T.

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