Results 261 to 270 of about 24,681,778 (305)

Edge ion parameters at the L–H transition on JET

Plasma Physics and Controlled Fusion, 2003
L–H transition experiments have recently been performed on JET to characterize the local edge ion parameters. Evidence of a threshold in the edge ion temperature to access the H-mode is presented and comparisons are made with edge electron temperature. These results provide the first scaling of pedestal ion temperature on JET.
Andrew, Y., Hawkes, N., O'Mullane, M., Sartori, R., Beurskens, M., Coffey, I., Joffrin, E., Loarte, A., McDonald, D., Prentice, R., Saibene, G., Suttrop, W., Zastrow, K., ASDEX Upgrade Team   +13 more
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L-H transition in the mega-amp spherical tokamak.

Physical review letters, 2002
H-mode plasmas have been achieved on the MAST spherical tokamak at input power considerably higher than predicted by conventional threshold scalings. Following L- H transition, a clear improvement in energy confinement is obtained, exceeding recent international scalings even at densities approaching the Greenwald density limit.
Akers, R.J., Counsell, G.F., Sykes, A., Appel, L.C., Arends, E.R., Byrom, C., Carolan, P.G., Conway, N.J., Cunningham, G., Dnestrovskij, A., Dnestrovskij, Y.N., Field, A.R., Fielding, S.J., Gryaznevich, M., Helander, P., Kirk, A., Korsholm, S., Martin, R., Meyer, H., Nightingale, M.P. S., Roach, C.M., Shevchenko, V., Torunianski, M., Walsh, M.J., Warrick, C.D.   +24 more
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Physics of GAM-initiated L–H transition in a tokamak

Plasma Physics and Controlled Fusion, 2016
Abstract Based on experimental observations using the TUMAN-3M and FT-2 tokamaks, and the results of gyrokinetic modeling of the interplay between turbulence and the geodesic acoustic mode (GAM) in these installations, a simple model is proposed for the analysis of the conditions required for L–H transition triggering by a burst of ...
L G Askinazi, A A Belokurov, V V Bulanin, A D Gurchenko, E Z Gusakov, T P Kiviniemi, S V Lebedev, V A Kornev, T Korpilo, S V Krikunov, S Leerink, M Machielsen, P Niskala, A V Petrov, A S Tukachinsky, A Yu Yashin, N A Zhubr   +16 more
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Neoclassical transport and poloidal rotation at the L-H transition

Physica Scripta, 1995
We address the question of establishing if, and under what physical and boundary conditions, the neoclassical transport is quantitatively capable of establishing high gradients in a narrow layer at the edge of an auxiliary heated tokamak plasma, and of driving poloidal rotation in the absence of external momentum input and vanishing parallel viscous ...
G Gervasini, E Lazzaro, E Minardi
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L‐H Transition Experiments in TJ‐II

Contributions to Plasma Physics, 2010
AbstractIn the TJ‐II stellarator, L‐ to H‐mode transitions are achieved under NBI heating conditions when operating with lithium coated walls. Several magnetic configurations have been explored in order to study the influence of the rotational transform in the transition.
T. Estrada, E. Ascasíbar, T. Happel, C. Hidalgo, E. Blanco, R. Jiménez‐Gómez, M. Liniers, D. López‐Bruna, F.L. Tabarés, D. Tafalla   +9 more
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Transport Modeling of L/H Transition in Tokamaks

Fusion Technology, 1995
In order to study the particle transport and the mechanism of the L/H transition in tokamaks, a one-dimensional transport code which describes the toroidal and poloidal plasma rotation as well as the radial electric field has been developed. The neoclassical transport, turbulent transport and ion orbit loss are included.
Y. Fuji, K. Itoh, A. Fukuyama, S.-I. Itoh   +3 more
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Statistical theory of L H transition in tokamaks*

Plasma Physics and Controlled Fusion, 2003
A statistical model for the bifurcation of the radial electric field Er is developed in view of describing L–H transitions of tokamak plasmas. Noise in micro-fluctuations is shown to lead to random changes of Er, if a deterministic approach allows for more than one solution.
S-I Itoh, K Itoh, S Toda
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A new model of the L–H transition in tokamaks*

Nuclear Fusion, 2012
Abstract A new model of the L–H transition in tokamaks is proposed, based on the criterion that the transition occurs when plasma turbulence and shear Alfvén waves compete in the vicinity of the last-closed flux surface. The model is used to predict the scaling of the H-mode access power, P L–H, with magnetic and plasma
W. Fundamenski, F. Militello, D. Moulton, D.C. McDonald   +3 more
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Ion collisionality and L–H transition in tokamaks

Physics of Fluids B: Plasma Physics, 1993
When the previous H-mode theory [K. C. Shaing and E. C. Crume, Jr., Phys. Rev. Lett. 63, 2369 (1989)] is extended to include a bi-Maxwellian ion distribution with both cold and hot ion components to model the effects of the non-Maxwellian distribution, the collisionality of the cold ions ν*ic becomes an irrelevant bifurcation parameter, as it is for ...
K. C. Shaing, P. J. Christenson
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A model for the L-H mode transition in Tokamaks

Nuclear Fusion, 1992
The ion orbit loss flux at the plasma edge is calculated, including the squeezing factor. A bifurcation solution is found by balancing the ion loss flux and the anomalous electron flux. At a certain level of anomalous electron flux, the plasma poloidal rotation increases with ion temperature.
Zhongtian Wang, G. Le Clair
openaire   +1 more source