A simple physical mechanism is described, which could trigger the Low-mode to High-mode (L-H) transition. The instantaneous ion density profile is significantly modified by a sudden temperature increase, because Larmor radii and banana orbit widths are proportional to thermal velocity. The electric fields that are observed in H-mode plasmas could be produced in the radial region where a large second derivative of the density profile exists, either by strong additional heating or by the heat pulse associated to a sawtooth crash. The L-H transition threshold for the time derivative of the ion temperature is of the order of magnitude of the values that are measured in the outer part of the plasma by electron temperature fast diagnostics at sawtooth crashes. This model agrees with the experimental evidence that L-H transitions are often triggered by a sawtooth crash, and the predicted dependence of the threshold on plasma parameters is fairly consistent with available data. (C) 1996 American Institute of Physics.
Moleti, A. (1996). Physical mechanism for the onset of radial electric fields in magnetically confined plasmas. PHYSICS OF PLASMAS, 3(4), 1284-1288.
Tipologia: | Articolo su rivista |
Citazione: | Moleti, A. (1996). Physical mechanism for the onset of radial electric fields in magnetically confined plasmas. PHYSICS OF PLASMAS, 3(4), 1284-1288. |
IF: | Con Impact Factor ISI |
Lingua: | English |
Settore Scientifico Disciplinare: | Settore FIS/01 - Fisica Sperimentale |
Revisione (peer review): | Sì, ma tipo non specificato |
Tipo: | Articolo |
Rilevanza: | Rilevanza internazionale |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1063/1.871753 ( |
Stato di pubblicazione: | Pubblicato |
Data di pubblicazione: | 1996 |
Titolo: | Physical mechanism for the onset of radial electric fields in magnetically confined plasmas |
Autori: | |
Autori: | Moleti, A |
Appare nelle tipologie: | 01 - Articolo su rivista |