@article{oai:nifs-repository.repo.nii.ac.jp:00000629, author = {Ohyabu, N. and Fujisawa, A. and Ashikawa, N. and deVries, P. and Emoto, M. and Funaba, H. and Goto, M. and Hamada, Y. and Iguchi, H. and Ida, K. and Itoh, K. and Isobe, M. and Idei, H. and Inagaki, S. and Inoue, N. and Ikeda, K. and Kado, S. and Kubo, S. and Kumazawa, R. and Khlopenkov, K. and Kaneko, O. and Kawahata, K. and Komori, A. and Kobuchi, T. and Lee, S. and Liang, Y. and Minami, T. and Miyazawa, J. and Masuzaki, S. and Matsuoka, K. and Morisaki, T. and Morita, S. and Murakami, S. and Mutoh, T. and Muto, S. and Narihara, K. and Nagayama, Y. and Nakamura, Y. and Nakanishi, H. and Nishimura, K. and Nishimura, S. and Noda, N. and Nomura, I. and Notake, T. and Okamura, S. and Ohdachi, S. and Ohkubo, K. and Oka, Y. and Osakabe, M. and Ozaki, T. and Peterson, B.J. and Pavlichenko, R.O. and Sagara, A. and Sakakibara, S. and Sakamoto, R. and Sasao, M. and Sato, K. and Sanuki, H. and Saito, K. and Sato, M. and Seki, T. and Shimizu, A. and Shimozuma, T. and Shoji, M. and Suzuki, H. and Sudo, S. and Sasao, H. and Takeiri, Y. and Tanaka, K. and Toi, K. and Tokuzawa, T. and Tsumori, K. and Tsuzuki, K. and Takechi, M. and Tamura, N. and Torii, Y. and Yamada, I. and Yamada, H. and Yamaguchi, S. and Yamazaki, K. and Yokoyama, M. and Yoshimura, Y. and Yamamoto, S. and Watanabe, K.Y. and Watanabe, T. and Watari, T. and Motojima, O. and Fujiwara, M.}, issue = {Issue 9}, journal = {Physics of Plasmas}, month = {May}, note = {In the discharges of the Large Helical Device [O. Motojima et al., Proceedings of the 16th Conference on Fusion Energy, Montreal, 1996 (International Atomic Energy Agency, Vienna, 1997), Vol. 3, p. 437], a significant enhancement of the energy confinement has been achieved with an edge thermal transport barrier, which exhibits a sharp gradient at the edge. Key features associated with the barrier are quite different from those seen in tokamaks (i) almost no change in particle (including impurity) transport, (ii) a gradual formation of the barrier, (iii) a very high ratio of the edge temperature to the average temperature, (iv) no edge relaxation phenomenon. In the electron cyclotron heating (ECH) heated discharges in the Compact Helical System [K. Matsuoka et al., in Proceedings of the 12th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Nice, France, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 2, p. 411], the internal electron transport barrier has been observed, which enhances the central electron temperature significantly. High shear of the radial electric field appears to suppress the turbulence in the core region and enhance the electron confinement there.}, title = {Thermal transport barrier in heliotron-type devices (Large Helical Device and Compact Helical System)}, volume = {Vol.7}, year = {2000} }