Results 151 to 160 of about 994 (182)

Turbulence and the nonlinear dynamics of sawteeth in tokamaks

Plasma Physics and Controlled Fusion, 1995
Tokamaks typically show cyclic behaviour (i.e. sawtooth oscillations) and this suggests strongly that these systems may be describable in terms of two reduced degrees of freedom, or equivalently two 'effective' physical variables. This leads us to further explore an earlier model which is based on a thermal instability within a central core region ...
F A Haas, A Thyagaraja
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Sawteeth, transport and electron cyclotron heating in T-10

Nuclear Fusion, 1988
The paper presents transport code simulations of sawteething discharges in T-10. Two models were employed to describe the sawtooth oscillations. In the first (reconnection) model the sawtooth collapse is caused by complete reconnection. In the second (turbulent) model the collapse is ascribed to increased radial transport caused by the generation of ...
Goedheer, W.J., Westerhof, E.
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Particle transport inferences from density sawteeth

Physics of Plasmas, 2014
Sawtooth oscillations in tokamaks are defined by their effect on electron temperature: a rapid flattening of the core profile followed by an outward heat pulse and a slow core recovery caused by central heating. Recent high-resolution, multi-chord interferometer measurements on JTEXT extend these studies to particle transport.
J. Chen, Q. Li, G. Zhuang, K. Liao, K. W. Gentle   +4 more
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Excitation of RSAEs during Sawteeth-Like Oscillation in EAST

Chinese Physics Letters, 2021
The excitation condition of reversed shear Alfvén eigenmodes (RSAEs) has been investigated during sawtooth-like oscillation in the EAST tokamak. The sawtooth-like phenomena can be reproduced in the configuration of reversed magnetic shear, and the threshold gradient of electron temperature is formed accordingly, together with the increasing of the ...
Ming Xu, Guoqiang Zhong, Baolong Hao, Wei Shen, Liqun Hu, Wei Chen, Zhiyong Qiu, Xuexi Zhang, Youjun Hu, Yingying Li, Hailin Zhao, Haiqing Liu, Bo Lyu   +12 more
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Operational region and sawteeth oscillation in the EAST tokamak

Plasma Physics and Controlled Fusion, 2007
The first plasma discharges were successfully achieved on the experimental advanced superconducting tokamak (EAST) in 2006. The sawteeth behaviours were observed by means of soft x-ray diagnostics and ECE signals in the EAST. The displacement and radius of the q = 1 surface was studied and compared with the result of equilibrium calculation.
H Q Liu, X Gao, J Y Zhao, L Q Hu, Y X Jie, B L Ling, Q Xu, A Ti, T F Ming, Y Yang, Z W Wu, J Wang, G S Xu, W Gao, G Q Zhong, Q Zang, Y J Shi, B Shen, Q Zhou, Y D Li, X Z Gong, J S Hu, Y W Sun, Y P Zhao, J R Luo, J S Mao, P D Weng, Y X Wan, X D Zhang, B N Wan, J Li, the EAST Team   +31 more
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Sawteeth-induced impurity transport in tokamak plasmas

Physics of Plasmas, 1996
A consistent picture of sawteeth-induced impurity transport is presented based on a recently given model for plasma redistribution by sawtooth crashes. The redistribution model is based on ideal magnetohydrodynamic conservation laws and assumes that the magnetic flux and the volume of the layers that reconnect during the crash are conserved.
A. Ödblom, D. Anderson, L.-G. Eriksson, M. Lisak   +3 more
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Measurement and analysis of neutron sawteeth on the Frascati Tokamak

Nuclear Fusion, 1990
The time evolution of neutron emission has been measured in sawtoothing discharges in the Frascati Tokamak (FT). The observed change in the neutron emission level during the sawtooth crash has been studied in terms of variations of the deuteron density and temperature.
P. Batistoni, M. Rapisarda, D. Anderson
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The effect of toroidal plasma rotation on sawteeth in MAST

Nuclear Fusion, 2006
Results from MAST concerning the effect of toroidal rotation driven by neutral beam injection (NBI) on sawteeth are presented. The sawtooth period is shown to increase as the co-NBI power, and thus the toroidal plasma rotation, is increased. As the counter-NBI power is increased, the sawtooth period decreases to a minimum that is shorter than in ...
I.T Chapman, T.C Hender, S Saarelma, S.E Sharapov, R.J Akers, N.J Conway, the MAST Team   +6 more
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The fast crash of the central temperature during sawteeth in tokamaks

The Physics of Fluids, 1987
A simple model of the crash phase of sawteeth in tokamaks is presented, which explains many of the significant experimental observations: small oscillations in the electron temperature prior to the crash (precursor), a short crash time, and large long-lived oscillations in the electron temperature following the crash (successor).
Robert G. Kleva, J. F. Drake, Richard E. Denton   +2 more
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Relation between the amplitudes of the temperature and current density sawteeth

Nuclear Fusion, 1991
According to the magnetic diffusion equation, the ratio of the normalized current density and the temperature sawteeth should lie between 2/3 and 3/4 on the tokamak magnetic axis if, as is the case in TEXTOR, the q = 1 magnetic surface remains still during the sawtooth ramp phase, and if the sawtooth amplitude is moderately small and rises linearly ...
G. Hasselberg, S.M. Khalil, A.L.M. Rogister, H. Soltwisch   +3 more
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