Confinement physics study in a small low aspect ratio helical device

CHS

S. Okamura, K. Matsuoka, R. Akiyama, D. S. Darrow, A. Ejiri, akihide fujisawa, M. Fujiwara, M. Goto, K. Ida, Hiroshi Idei, H. Iguchi, N. Inoue, M. Isobe, K. Itoh, S. Kado, al et al

Research output: Contribution to journalArticle

44 Citations (Scopus)

Abstract

Variation of the plasma position relative to the centre of the helical coil winding is a very effective means of controlling the MHD stability and the trapped particle confinement in heliotron/torsatron systems, but improving one of these two characteristics with this parameter simultaneously has a detrimental effect on the other. The inward shifted configuration is favourable for drift orbit optimization but is predicted to be unstable according to the Mercier criterion. Various physics problems, such as electric field structure, plasma rotation and MHD phenomena, have been studied in the Compact Helical System (CHS) with a compromise intermediate position. With this standard configuration, CHS has yielded experimental results that contribute to the understanding of general toroidal confinement physics and low aspect ratio helical systems. In the recent experiments, it was found that a wide range of inward shifted configurations give stable plasma discharges without any restriction to the special pressure profile. Such an enhanced range of operation made it possible to study experimentally the drift orbit optimized configuration in heliotron/torsatron systems. The effect of configuration improvement was studied with plasmas in a low collisionality regime.

Original languageEnglish
Pages (from-to)1337-1350
Number of pages14
JournalNuclear Fusion
Volume39
Issue numberSpecial Issue
Publication statusPublished - Sep 1999
Externally publishedYes

Fingerprint

low aspect ratio
physics
configurations
orbits
trapped particles
plasma jets
constrictions
coils
optimization
electric fields
profiles

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Condensed Matter Physics
  • Nuclear and High Energy Physics

Cite this

Okamura, S., Matsuoka, K., Akiyama, R., Darrow, D. S., Ejiri, A., fujisawa, A., ... et al, A. (1999). Confinement physics study in a small low aspect ratio helical device: CHS. Nuclear Fusion, 39(Special Issue), 1337-1350.

Confinement physics study in a small low aspect ratio helical device : CHS. / Okamura, S.; Matsuoka, K.; Akiyama, R.; Darrow, D. S.; Ejiri, A.; fujisawa, akihide; Fujiwara, M.; Goto, M.; Ida, K.; Idei, Hiroshi; Iguchi, H.; Inoue, N.; Isobe, M.; Itoh, K.; Kado, S.; et al, al.

In: Nuclear Fusion, Vol. 39, No. Special Issue, 09.1999, p. 1337-1350.

Research output: Contribution to journalArticle

Okamura, S, Matsuoka, K, Akiyama, R, Darrow, DS, Ejiri, A, fujisawa, A, Fujiwara, M, Goto, M, Ida, K, Idei, H, Iguchi, H, Inoue, N, Isobe, M, Itoh, K, Kado, S & et al, A 1999, 'Confinement physics study in a small low aspect ratio helical device: CHS', Nuclear Fusion, vol. 39, no. Special Issue, pp. 1337-1350.
Okamura S, Matsuoka K, Akiyama R, Darrow DS, Ejiri A, fujisawa A et al. Confinement physics study in a small low aspect ratio helical device: CHS. Nuclear Fusion. 1999 Sep;39(Special Issue):1337-1350.
Okamura, S. ; Matsuoka, K. ; Akiyama, R. ; Darrow, D. S. ; Ejiri, A. ; fujisawa, akihide ; Fujiwara, M. ; Goto, M. ; Ida, K. ; Idei, Hiroshi ; Iguchi, H. ; Inoue, N. ; Isobe, M. ; Itoh, K. ; Kado, S. ; et al, al. / Confinement physics study in a small low aspect ratio helical device : CHS. In: Nuclear Fusion. 1999 ; Vol. 39, No. Special Issue. pp. 1337-1350.
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