Simultaneous realization of a high density edge transport barrier and an improved L-mode on CHS

Takashi Minami, Shoichi Okamura, Chihiro Suzuki, Keiji Matsuo, Tetsutarou Oishi, Tsuyoshi Akiyama, Mitsutaka Isobe, Katsumi Ida, Haruhisa Nakano, Akihide Fujisawa, Kenichi Nagaoka, Mikiro Yoshinuma, Yasuo Yoshimura, Kazuo Toi, Shinsuke Ohshima, Masaki Takeuchi, Harukazu Iguchi, Shin Nishimura, Akihiro Shimizu, Keisuke MatsuokaChihiro Takahashi

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1 Citation (Scopus)


An edge transport barrier (ETB) formation and an improved L-mode (IL mode) have been simultaneously realized in the high density region (n̄e ∼ 1.2 × 1020m?3) on the Compact Helical System (CHS). When the ETB is formed during the IL mode, the density reduction in the edge region is suppressed by the barrier formation. As a result of the continuous increase in the temperature by the IL mode, the stored energy during the combined mode increased up to the maximum stored energy (Wp ∼ 9.4 kJ) recorded in the CHS experiments. The plasma pressure in the peripheral region increases up to three times compared with the L-mode, and the large edge plasma pressure gradient is formed accompanying the pedestal structure. This is caused by the anomalous transport reduction that is confirmed by the sharp drop in the density fluctuation in the edge region. The neutral particle density reduction in the peripheral region and the metallic impurity accumulation in the core plasma are simultaneously observed during the high density ETB formation.

Original languageEnglish
Article number085018
JournalNuclear Fusion
Issue number8
Publication statusPublished - Sep 21 2009
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Nuclear and High Energy Physics
  • Condensed Matter Physics


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