[Table of Contents]

Plasma and Fusion Research

Volume 5, S2083 (2010)

Regular Articles

Reconstruction of Vacuum Magnetic Flux in QUEST
Masaki ISHIGURO, Kazuaki HANADA1), Kazuo NAKAMURA1), Osamu MITARAI2), Hideki ZUSHI1), Hiroshi IDEI1), Mizuki SAKAMOTO1), Makoto HASEGAWA1), Yuta HIGASHIZONO1), Yuichi TAKASE3), Takashi MAEKAWA4), Yasuaki KISHIMOTO4), Shoji KAWASAKI1), Hisatoshi NAKASHIMA1) and Aki HIGASHIJIMA1)
Interdisciplinary Graduate School of Engineering Science Kyushu University, Kasuga 816-8580, Japan
1)
Research Institute for Applied Mechanics, Kyushu University, Kasuga 816-8580, Japan
2)
Liberal Arts Education Center, Kumamoto Campus, Tokai University, 9-1-1 Toroku, Kumamoto 862-8652, Japan
3)
Graduate School of Frontier Science, University Tokyo, Kashiwa 277-8561, Japan
4)
Graduate School of Energy Scienece, Kyoto University, Kyoto 606-8502, Japan
(Received 7 December 2009 / Accepted 13 May 2010 / Published 10 December 2010)

Abstract

It is important to determine the best method for reconstructing the magnetic flux when eddy currents are significantly induced during magnetic measurement in spherical tokamaks (STs). Four methods for this reconstruction are investigated, and the calculated magnetic fluxes are compared to those measured in the cavity of a vacuum vessel. The results show that the best method is the one that uses currents from virtual coils for reconstruction. In this method, the placement of the virtual coils is optimized with numerical simulations using the Akaike information criterion (AIC), which indicates the goodness of fit of models used to fit measured data. The virtual coils are set on a line 15 cm outside the vacuum vessel.

Keywords

spherical tokamak, magnetic flux reconstruction, eddy current, magnetic measurement, flux loop

DOI: 10.1585/pfr.5.S2083

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References

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This paper may be cited as follows:

Masaki ISHIGURO, Kazuaki HANADA, Kazuo NAKAMURA, Osamu MITARAI, Hideki ZUSHI, Hiroshi IDEI, Mizuki SAKAMOTO, Makoto HASEGAWA, Yuta HIGASHIZONO, Yuichi TAKASE, Takashi MAEKAWA, Yasuaki KISHIMOTO, Shoji KAWASAKI, Hisatoshi NAKASHIMA and Aki HIGASHIJIMA, Plasma Fusion Res. 5, S2083 (2010).