Heating and confinement characteristics of second harmonic heating in the ion cyclotron range of frequencies on the jt-60 tokamak

T. Fujii, H. Kimura, M. Saigusa, S. Moriyama, K. Hamamatsu, K. Annoh, T. Fukuda, S. Ishida, N. Kobayashi, Y. Koide, H. Kubo, Y. Kusama, K. Nagashima, M. Nemoto, T. Nishitani, Y. Ogawa, A. Sakasai, M. Sato, S. Shinozaki, T. SugieM. Terakado, K. Tobita, H. Yoshida

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Abstract

Results are presented of the second harmonic heating experiments in the ion cyclotron range of frequencies (ICRF) on JT-60. Heating and confinement characteristics are investigated by using the hydrogen second harmonic (H-majority 2wjh) scheme and the hydrogen minority second harmonic (H-minority 2 ώ ch) scheme (nn/nHe « 0.1) in two toroidal phasing modes of antenna currents, in phase ((0, 0)) and out of phase ((π, 0)), at Pjc ^ 3 MW, ñj = (1.3-6.6) X 10 ” m‘^ and Ip = 1-2.4 MA. Efficient plasma heating has been demonstrated in both heating schemes. Intense non-Maxwellian ion tails are observed at low density. Sawtooth oscillations with an enhanced period in the electron temperature are found over a wide range of electron densities. The incremental energy confinement time, Te', for (tt, 0) phasing is larger than for (0, 0) phasing, irrespective of the heating scheme. In particular, H-minority 2wjh heating with (ir, 0) phasing shows excellent plasma heating with * 100-120 ms, which is larger than that of neutral beam injection (NBI) heating by a factor of about two. Different dependences of tÈ“ on Ip are obtained in the two heating schemes. The (0, 0) phasing data of ' in H-majority 20^» heating increase with Ip up to 1.9 MA, while the (tt, 0) phasing data in H-minority 2ü>ch heating are almost constant with Ip up to 2.4 MA. The global energy confinement shows an L-mode behaviour. The energy confinement time for H-minority 2uch heating at high density agrees well with the Shimomura-Odajima scaling.

Original languageEnglish
Pages (from-to)137-154
Number of pages18
JournalNuclear Fusion
Volume31
Issue number1
DOIs
Publication statusPublished - 1991 Jan
Externally publishedYes

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Condensed Matter Physics

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