TY - JOUR
T1 - An assessment of limit cycle oscillation dynamics prior to L-H transition
AU - Itoh, Kimitaka
AU - Itoh, Sanae I.
AU - Fujisawa, Akihide
N1 - Funding Information:
Authors wish to thank discussion and collaboration with Y. Miura, T. Kobayashi, T. Ido, K. Kamiya, Y. Nagashima, S. Inagaki, K. Ida, A. Fukuyama, P. H. Diamond, K. Hallatschek, G. R. Tynan, U. Stroth, J. Q. Dong, K. J. Zhao, and C. Hidalgo, and supports by M. Mori and Y. Kamada. The discussions at the first, second and 3rd APTWG Meetings (in particular 'call for critical experimental test' by P. H. Diamond at the 2nd APTWG meeting), and at 14th International Workshop on H-mode Physics and Transport Barriers are also acknowledged. This work is partly supported by the Grant-in-Aid for Scientific Research of JSPF, Japan (21224014, 23244113), the collaboration programs of RIAM of Kyushu University, of JAEA and of NIFS, and by Asada Science Foundation
Publisher Copyright:
© 2013 The Japan Society of Plasma Science and Nuclear Fusion Research.
PY - 2013
Y1 - 2013
N2 - In this article, experimental observations of limit cycle oscillations (LCO) that precede L-to-H transition are discussed. Issues are: (1) the existence of zonal flows, (2) spatio-temporal evolutions of turbulence intensity, and (3) periodic generations/decays of mean radial electric field and density. The role of Reynolds stress to accelerate the LCO flow is also addressed. The propagation of changes of the density gradient and turbulence amplitude into the core is commented. Varieties in experimental reports on these issues are explained, and possible origins of different interpretations are discussed. Problem definitions for the future research for resolution are presented.
AB - In this article, experimental observations of limit cycle oscillations (LCO) that precede L-to-H transition are discussed. Issues are: (1) the existence of zonal flows, (2) spatio-temporal evolutions of turbulence intensity, and (3) periodic generations/decays of mean radial electric field and density. The role of Reynolds stress to accelerate the LCO flow is also addressed. The propagation of changes of the density gradient and turbulence amplitude into the core is commented. Varieties in experimental reports on these issues are explained, and possible origins of different interpretations are discussed. Problem definitions for the future research for resolution are presented.
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U2 - 10.1585/pfr.8.1102168
DO - 10.1585/pfr.8.1102168
M3 - Article
AN - SCOPUS:84936783237
VL - 8
JO - Plasma and Fusion Research
JF - Plasma and Fusion Research
SN - 1880-6821
M1 - 1102168
ER -