Radial build between helical coil and plasma in the Large Helical Device

N. Ohyabu, K. Yamazaki, Hantao Ji, S. Imagawa, H. Kaneko, S. Morimoto, N. Noda, T. Satow, J. Yamamoto, O. Motojima, Design Group LHD Design Group

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


The Large Helical Device (LHD) is a heliotron/torsatron-type confinement device (B = 4 T, R = 3.9 m) equipped with a helical divertor. In the LHD configuration, the plasma region is shifted inwards approximately a third of the plasma minor radius relative to the center of the two pairing helical coils, thus making the distance between the coil center and the edge plasma small, 328 mm on the small major radius side of the torus. Within this space, many components must be installed, such as the superconducting helical coil (163), its coil can (45), the thermal shield (30), the vacuum gap (35), the plasma vacuum vessel (15), the first wall (25) (the numbers in the parentheses are allocated radial space in mm for the respective components). Effective edge plasma control by the divertor requires a space of more than 15 mm between the plasma and the first wall. To meet the above space requirement, the thickness of the helical coil is designed to be as small as possible, yet the coil current density and maximum field strength are within the limits of reliable coil operation.

Original languageEnglish (US)
Pages (from-to)73-77
Number of pages5
JournalFusion Engineering and Design
Issue numberC
StatePublished - Jan 1993
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Nuclear Energy and Engineering
  • General Materials Science
  • Mechanical Engineering


Dive into the research topics of 'Radial build between helical coil and plasma in the Large Helical Device'. Together they form a unique fingerprint.

Cite this