[Table of Contents]

Plasma and Fusion Research

Volume 7, 2405008 (2012)

Regular Articles

Long-Term Monitoring of Hydraulic Characteristics of LHD Poloidal Coils
Kazuya TAKAHATA, Sadatomo MORIUCHI, Kouki OOBA, Toshiyuki MITO and Shinsaku IMAGAWA
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
(Received 30 November 2011 / Accepted 24 January 2012 / Published 17 February 2012)


We present a fourteen-year data summary of the hydraulic characteristics of the large helical device (LHD) poloidal coils. The superconductors of the poloidal coils are cable-in-conduit conductors (CICC) cooled by circulated supercritical helium. The long-term operation of the LHD demonstrates that the initial hydraulic characteristics can be maintained without flow obstruction. Fine mesh filters installed at the inlet trapped impurities during cool-down of the coils, confirmed by monitoring the pressure drop of the filters. The filters have an important role in removing particles of impurities in the helium and maintaining the hydraulic characteristics of the coils.


LHD, superconducting magnet, cable-in-conduit conductor, hydraulic characteristic, friction factor

DOI: 10.1585/pfr.7.2405008


  • [1] M. Fujiwara et al., J. Fusion Energy 15, 7 (1996).
  • [2] K. Takahata et al., IEEE Trans. Magn. 32, 2252 (1996).
  • [3] K. Takahata et al., Advances in Cryogenic Engineering, Vol. 45 (Kluwer Academic/Plemum Publishers, New York, 2000) p. 1111.
  • [4] User's Guide to HEPAK Version 3.30, Cryodata Inc. (1994).
  • [5] H. Katheder, Cryogenics 34, 595 (1994).

This paper may be cited as follows:

Kazuya TAKAHATA, Sadatomo MORIUCHI, Kouki OOBA, Toshiyuki MITO and Shinsaku IMAGAWA, Plasma Fusion Res. 7, 2405008 (2012).