Configuration flexibility and extended regimes in Large Helical Device

H. Yamada; A. Komori; N. Ohyabu; O. Kaneko; K. Kawahata; K. Y. Watanabe; S. Sakakibara; S. Murakami; K. Ida; R. Sakamoto; Y. Liang; J. Miyazawa; K. Tanaka; Y. Narushima; S. Morita; S. Masuzaki; T. Morisaki; N. Ashikawa; L. R. Baylor; W. A. Cooper; M. Emoto; P. W. Fisher; H. Funaba; M. Goto; H. Idei; K. Ikeda; S. Inagaki; N. Inoue; M. Isobe; K. Khlopenkov; T. Kobuchi; A. Kostrioukov; S. Kubo; T. Kuroda; R. Kumazawa; T. Minami; S. Muto; T. Mutoh; Y. Nagayama; N. Nakajima; Y. Nakamura; H. Nakanishi; K. Narihara; K. Nishimura; N. Noda; T. Notake; S. Ohdachi; Y. Oka; M. Osakabe; T. Ozaki; B. J. Peterson; G. Rewoldt; A. Sagara; K. Saito; H. Sasao; M. Sasao; K. Sato; M. Sato; T. Seki; H. Sugama; T. Shimozuma; M. Shoji; H. Suzuki; Y. Takeiri; N. Tamura; K. Toi; T. Tokuzawa; Y. Torii; K. Tsumori; T. Watanabe; I. Yamada; S. Yamamoto; M. Yokoyama; Y. Yoshimura; T. Watari; Y. Xu; K. Itoh; K. Matsuoka; K. Ohkubo; T. Satow; S. Sudo; T. Uda; K. Yamazaki; O. Motojima; M. Fujiwara

doi:10.1088/0741-3335/43/12A/305

Configuration flexibility and extended regimes in Large Helical Device

H. Yamada
, A. Komori
, N. Ohyabu
, O. Kaneko
, K. Kawahata
, K. Y. Watanabe
, S. Sakakibara
, S. Murakami
, K. Ida
, R. Sakamoto
, Y. Liang
, J. Miyazawa
, K. Tanaka
, Y. Narushima
, S. Morita
, S. Masuzaki
, T. Morisaki
, N. Ashikawa
, L. R. Baylor
, W. A. Cooper

M. Emoto, P. W. Fisher, H. Funaba, M. Goto, H. Idei, K. Ikeda, S. Inagaki, N. Inoue, M. Isobe, K. Khlopenkov, T. Kobuchi, A. Kostrioukov, S. Kubo, T. Kuroda, R. Kumazawa, T. Minami, S. Muto, T. Mutoh, Y. Nagayama, N. Nakajima, Y. Nakamura, H. Nakanishi, K. Narihara, K. Nishimura, N. Noda, T. Notake, S. Ohdachi, Y. Oka, M. Osakabe, T. Ozaki, B. J. Peterson, G. Rewoldt, A. Sagara, K. Saito, H. Sasao, M. Sasao, K. Sato, M. Sato, T. Seki, H. Sugama, T. Shimozuma, M. Shoji, H. Suzuki, Y. Takeiri, N. Tamura, K. Toi, T. Tokuzawa, Y. Torii, K. Tsumori, T. Watanabe, I. Yamada, S. Yamamoto, M. Yokoyama, Y. Yoshimura, T. Watari, Y. Xu, K. Itoh, K. Matsuoka, K. Ohkubo, T. Satow, S. Sudo, T. Uda, K. Yamazaki, O. Motojima, M. Fujiwara

Fusion Energy Division

Research output: Contribution to journal › Article › peer-review

100 Scopus citations

Abstract

Recent experimental results in the Large Helical Device have indicated that a large pressure gradient can be formed beyond the stability criterion for the Mercier (high-n) mode. While the stability against an interchange mode is violated in the inward-shifted configuration due to an enhancement of the magnetic hill, the neoclassical transport and confinement of high-energy particle are, in contrast, improved by this inward shift. Mitigation of the unfavourable effects of MHD instability has led to a significant extension of the operational regime. Achievements of the stored energy of 1 MJ and the volume-averaged beta of 3% are representative results from this finding. A confinement enhancement factor above the international stellarator scaling ISS95 is also maintained around 1.5 towards a volume-averaged beta, 〈β〉, of 3%. Configuration studies on confinement and MHD characteristics emphasize the superiority of the inward-shifted geometry to other geometries. The emergence of coherent modes appears to be consistent with the linear ideal MHD theory; however, the inward-shifted configuration has reduced heat transport in spite of a larger amplitude of magnetic fluctuation than the outward-shifted configuration. While neoclassical helical ripple transport becomes visible for the outward-shifted configuration in the collisionless regime, the inward-shifted configuration does not show any degradation of confinement deep in the collisionless regime (v* < 0.1). The distinguished characteristics observed in the inward-shifted configuration help in creating a new perspective of MHD stability and related transport in net current-free plasmas. The first result of the pellet launching at different locations is also reported.

Original language	English
Pages (from-to)	A55-A71
Journal	Plasma Physics and Controlled Fusion
Volume	43
Issue number	12A
DOIs	https://doi.org/10.1088/0741-3335/43/12A/305
State	Published - 2001

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10.1088/0741-3335/43/12A/305

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Yamada, H., Komori, A., Ohyabu, N., Kaneko, O., Kawahata, K., Watanabe, K. Y., Sakakibara, S., Murakami, S., Ida, K., Sakamoto, R., Liang, Y., Miyazawa, J., Tanaka, K., Narushima, Y., Morita, S., Masuzaki, S., Morisaki, T., Ashikawa, N., Baylor, L. R., ... Fujiwara, M. (2001). Configuration flexibility and extended regimes in Large Helical Device. Plasma Physics and Controlled Fusion, 43(12A), A55-A71. https://doi.org/10.1088/0741-3335/43/12A/305

@article{8272f43293144f83a7479068eec99fb7,

title = "Configuration flexibility and extended regimes in Large Helical Device",

abstract = "Recent experimental results in the Large Helical Device have indicated that a large pressure gradient can be formed beyond the stability criterion for the Mercier (high-n) mode. While the stability against an interchange mode is violated in the inward-shifted configuration due to an enhancement of the magnetic hill, the neoclassical transport and confinement of high-energy particle are, in contrast, improved by this inward shift. Mitigation of the unfavourable effects of MHD instability has led to a significant extension of the operational regime. Achievements of the stored energy of 1 MJ and the volume-averaged beta of 3\% are representative results from this finding. A confinement enhancement factor above the international stellarator scaling ISS95 is also maintained around 1.5 towards a volume-averaged beta, 〈β〉, of 3\%. Configuration studies on confinement and MHD characteristics emphasize the superiority of the inward-shifted geometry to other geometries. The emergence of coherent modes appears to be consistent with the linear ideal MHD theory; however, the inward-shifted configuration has reduced heat transport in spite of a larger amplitude of magnetic fluctuation than the outward-shifted configuration. While neoclassical helical ripple transport becomes visible for the outward-shifted configuration in the collisionless regime, the inward-shifted configuration does not show any degradation of confinement deep in the collisionless regime (v* < 0.1). The distinguished characteristics observed in the inward-shifted configuration help in creating a new perspective of MHD stability and related transport in net current-free plasmas. The first result of the pellet launching at different locations is also reported.",

author = "H. Yamada and A. Komori and N. Ohyabu and O. Kaneko and K. Kawahata and Watanabe, \{K. Y.\} and S. Sakakibara and S. Murakami and K. Ida and R. Sakamoto and Y. Liang and J. Miyazawa and K. Tanaka and Y. Narushima and S. Morita and S. Masuzaki and T. Morisaki and N. Ashikawa and Baylor, \{L. R.\} and Cooper, \{W. A.\} and M. Emoto and Fisher, \{P. W.\} and H. Funaba and M. Goto and H. Idei and K. Ikeda and S. Inagaki and N. Inoue and M. Isobe and K. Khlopenkov and T. Kobuchi and A. Kostrioukov and S. Kubo and T. Kuroda and R. Kumazawa and T. Minami and S. Muto and T. Mutoh and Y. Nagayama and N. Nakajima and Y. Nakamura and H. Nakanishi and K. Narihara and K. Nishimura and N. Noda and T. Notake and S. Ohdachi and Y. Oka and M. Osakabe and T. Ozaki and Peterson, \{B. J.\} and G. Rewoldt and A. Sagara and K. Saito and H. Sasao and M. Sasao and K. Sato and M. Sato and T. Seki and H. Sugama and T. Shimozuma and M. Shoji and H. Suzuki and Y. Takeiri and N. Tamura and K. Toi and T. Tokuzawa and Y. Torii and K. Tsumori and T. Watanabe and I. Yamada and S. Yamamoto and M. Yokoyama and Y. Yoshimura and T. Watari and Y. Xu and K. Itoh and K. Matsuoka and K. Ohkubo and T. Satow and S. Sudo and T. Uda and K. Yamazaki and O. Motojima and M. Fujiwara",

year = "2001",

doi = "10.1088/0741-3335/43/12A/305",

language = "English",

volume = "43",

pages = "A55--A71",

journal = "Plasma Physics and Controlled Fusion",

issn = "0741-3335",

publisher = "IOP Publishing",

number = "12A",

}

Yamada, H, Komori, A, Ohyabu, N, Kaneko, O, Kawahata, K, Watanabe, KY, Sakakibara, S, Murakami, S, Ida, K, Sakamoto, R, Liang, Y, Miyazawa, J, Tanaka, K, Narushima, Y, Morita, S, Masuzaki, S, Morisaki, T, Ashikawa, N, Baylor, LR, Cooper, WA, Emoto, M, Fisher, PW, Funaba, H, Goto, M, Idei, H, Ikeda, K, Inagaki, S, Inoue, N, Isobe, M, Khlopenkov, K, Kobuchi, T, Kostrioukov, A, Kubo, S, Kuroda, T, Kumazawa, R, Minami, T, Muto, S, Mutoh, T, Nagayama, Y, Nakajima, N, Nakamura, Y, Nakanishi, H, Narihara, K, Nishimura, K, Noda, N, Notake, T, Ohdachi, S, Oka, Y, Osakabe, M, Ozaki, T, Peterson, BJ, Rewoldt, G, Sagara, A, Saito, K, Sasao, H, Sasao, M, Sato, K, Sato, M, Seki, T, Sugama, H, Shimozuma, T, Shoji, M, Suzuki, H, Takeiri, Y, Tamura, N, Toi, K, Tokuzawa, T, Torii, Y, Tsumori, K, Watanabe, T, Yamada, I, Yamamoto, S, Yokoyama, M, Yoshimura, Y, Watari, T, Xu, Y, Itoh, K, Matsuoka, K, Ohkubo, K, Satow, T, Sudo, S, Uda, T, Yamazaki, K, Motojima, O & Fujiwara, M 2001, 'Configuration flexibility and extended regimes in Large Helical Device', Plasma Physics and Controlled Fusion, vol. 43, no. 12A, pp. A55-A71. https://doi.org/10.1088/0741-3335/43/12A/305

TY - JOUR

T1 - Configuration flexibility and extended regimes in Large Helical Device

AU - Yamada, H.

AU - Komori, A.

AU - Ohyabu, N.

AU - Kaneko, O.

AU - Kawahata, K.

AU - Watanabe, K. Y.

AU - Sakakibara, S.

AU - Murakami, S.

AU - Ida, K.

AU - Sakamoto, R.

AU - Liang, Y.

AU - Miyazawa, J.

AU - Tanaka, K.

AU - Narushima, Y.

AU - Morita, S.

AU - Masuzaki, S.

AU - Morisaki, T.

AU - Ashikawa, N.

AU - Baylor, L. R.

AU - Cooper, W. A.

AU - Emoto, M.

AU - Fisher, P. W.

AU - Funaba, H.

AU - Goto, M.

AU - Idei, H.

AU - Ikeda, K.

AU - Inagaki, S.

AU - Inoue, N.

AU - Isobe, M.

AU - Khlopenkov, K.

AU - Kobuchi, T.

AU - Kostrioukov, A.

AU - Kubo, S.

AU - Kuroda, T.

AU - Kumazawa, R.

AU - Minami, T.

AU - Muto, S.

AU - Mutoh, T.

AU - Nagayama, Y.

AU - Nakajima, N.

AU - Nakamura, Y.

AU - Nakanishi, H.

AU - Narihara, K.

AU - Nishimura, K.

AU - Noda, N.

AU - Notake, T.

AU - Ohdachi, S.

AU - Oka, Y.

AU - Osakabe, M.

AU - Ozaki, T.

AU - Peterson, B. J.

AU - Rewoldt, G.

AU - Sagara, A.

AU - Saito, K.

AU - Sasao, H.

AU - Sasao, M.

AU - Sato, K.

AU - Sato, M.

AU - Seki, T.

AU - Sugama, H.

AU - Shimozuma, T.

AU - Shoji, M.

AU - Suzuki, H.

AU - Takeiri, Y.

AU - Tamura, N.

AU - Toi, K.

AU - Tokuzawa, T.

AU - Torii, Y.

AU - Tsumori, K.

AU - Watanabe, T.

AU - Yamada, I.

AU - Yamamoto, S.

AU - Yokoyama, M.

AU - Yoshimura, Y.

AU - Watari, T.

AU - Xu, Y.

AU - Itoh, K.

AU - Matsuoka, K.

AU - Ohkubo, K.

AU - Satow, T.

AU - Sudo, S.

AU - Uda, T.

AU - Yamazaki, K.

AU - Motojima, O.

AU - Fujiwara, M.

PY - 2001

Y1 - 2001

N2 - Recent experimental results in the Large Helical Device have indicated that a large pressure gradient can be formed beyond the stability criterion for the Mercier (high-n) mode. While the stability against an interchange mode is violated in the inward-shifted configuration due to an enhancement of the magnetic hill, the neoclassical transport and confinement of high-energy particle are, in contrast, improved by this inward shift. Mitigation of the unfavourable effects of MHD instability has led to a significant extension of the operational regime. Achievements of the stored energy of 1 MJ and the volume-averaged beta of 3% are representative results from this finding. A confinement enhancement factor above the international stellarator scaling ISS95 is also maintained around 1.5 towards a volume-averaged beta, 〈β〉, of 3%. Configuration studies on confinement and MHD characteristics emphasize the superiority of the inward-shifted geometry to other geometries. The emergence of coherent modes appears to be consistent with the linear ideal MHD theory; however, the inward-shifted configuration has reduced heat transport in spite of a larger amplitude of magnetic fluctuation than the outward-shifted configuration. While neoclassical helical ripple transport becomes visible for the outward-shifted configuration in the collisionless regime, the inward-shifted configuration does not show any degradation of confinement deep in the collisionless regime (v* < 0.1). The distinguished characteristics observed in the inward-shifted configuration help in creating a new perspective of MHD stability and related transport in net current-free plasmas. The first result of the pellet launching at different locations is also reported.

AB - Recent experimental results in the Large Helical Device have indicated that a large pressure gradient can be formed beyond the stability criterion for the Mercier (high-n) mode. While the stability against an interchange mode is violated in the inward-shifted configuration due to an enhancement of the magnetic hill, the neoclassical transport and confinement of high-energy particle are, in contrast, improved by this inward shift. Mitigation of the unfavourable effects of MHD instability has led to a significant extension of the operational regime. Achievements of the stored energy of 1 MJ and the volume-averaged beta of 3% are representative results from this finding. A confinement enhancement factor above the international stellarator scaling ISS95 is also maintained around 1.5 towards a volume-averaged beta, 〈β〉, of 3%. Configuration studies on confinement and MHD characteristics emphasize the superiority of the inward-shifted geometry to other geometries. The emergence of coherent modes appears to be consistent with the linear ideal MHD theory; however, the inward-shifted configuration has reduced heat transport in spite of a larger amplitude of magnetic fluctuation than the outward-shifted configuration. While neoclassical helical ripple transport becomes visible for the outward-shifted configuration in the collisionless regime, the inward-shifted configuration does not show any degradation of confinement deep in the collisionless regime (v* < 0.1). The distinguished characteristics observed in the inward-shifted configuration help in creating a new perspective of MHD stability and related transport in net current-free plasmas. The first result of the pellet launching at different locations is also reported.

UR - https://www.scopus.com/pages/publications/6444244293

U2 - 10.1088/0741-3335/43/12A/305

DO - 10.1088/0741-3335/43/12A/305

M3 - Article

AN - SCOPUS:6444244293

SN - 0741-3335

VL - 43

SP - A55-A71

JO - Plasma Physics and Controlled Fusion

JF - Plasma Physics and Controlled Fusion

IS - 12A

ER -

Configuration flexibility and extended regimes in Large Helical Device

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