Abstract
The disruptions are one of the major obstacles to present day tokamaks extrapolation to fusion reactors. We have recently proposed a piloting discharge strategy on TORE SUPRA to prevent density limit disruptions. This strategy is based on the use of the Ergodic Divertor (ED). We have observed that the ED stabilizes the m=2 n=1 tearing mode and that in deuterium discharges limited by the outboard limiter it induces a fast decrease of the plasma density. The piloting strategy is taken in three steps: (1) the approach of the density limit is detected by a threshold on the MHD activity amplitude; (2) the gas puff is switched off; (3) the ED is turned on. Then the m=2 n=1 tearing mode is stabilized the density decreases and the disruption is avoided. This strategy has already been successully tested on about 20 specific deuterium shots with 2.5<4.5 in which the density limit is approached by ramping up the density with gas puffing. In this paper, experimental data are reported and analyzed. First, the principle of the ED and the density limit disruption phenomenology are briefly recalled. Then the ED effect on plasma density, radiated power and MHD activity are analyzed, and the piloting
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Citation Formats
Vallet, J C, Poutchy, L, Mohamed-Benkadda, M S, Edery, D, Joffrin, E, Lecoustey, P, Pecquet, A L, Samain, A, and Talvard, M.
The ergodic divertor a way to prevent major disruptions.
France: N. p.,
1991.
Web.
Vallet, J C, Poutchy, L, Mohamed-Benkadda, M S, Edery, D, Joffrin, E, Lecoustey, P, Pecquet, A L, Samain, A, & Talvard, M.
The ergodic divertor a way to prevent major disruptions.
France.
Vallet, J C, Poutchy, L, Mohamed-Benkadda, M S, Edery, D, Joffrin, E, Lecoustey, P, Pecquet, A L, Samain, A, and Talvard, M.
1991.
"The ergodic divertor a way to prevent major disruptions."
France.
@misc{etde_10131462,
title = {The ergodic divertor a way to prevent major disruptions}
author = {Vallet, J C, Poutchy, L, Mohamed-Benkadda, M S, Edery, D, Joffrin, E, Lecoustey, P, Pecquet, A L, Samain, A, and Talvard, M}
abstractNote = {The disruptions are one of the major obstacles to present day tokamaks extrapolation to fusion reactors. We have recently proposed a piloting discharge strategy on TORE SUPRA to prevent density limit disruptions. This strategy is based on the use of the Ergodic Divertor (ED). We have observed that the ED stabilizes the m=2 n=1 tearing mode and that in deuterium discharges limited by the outboard limiter it induces a fast decrease of the plasma density. The piloting strategy is taken in three steps: (1) the approach of the density limit is detected by a threshold on the MHD activity amplitude; (2) the gas puff is switched off; (3) the ED is turned on. Then the m=2 n=1 tearing mode is stabilized the density decreases and the disruption is avoided. This strategy has already been successully tested on about 20 specific deuterium shots with 2.5<4.5 in which the density limit is approached by ramping up the density with gas puffing. In this paper, experimental data are reported and analyzed. First, the principle of the ED and the density limit disruption phenomenology are briefly recalled. Then the ED effect on plasma density, radiated power and MHD activity are analyzed, and the piloting strategy to prevent density limit disruptions is discussed.}
place = {France}
year = {1991}
month = {Dec}
}
title = {The ergodic divertor a way to prevent major disruptions}
author = {Vallet, J C, Poutchy, L, Mohamed-Benkadda, M S, Edery, D, Joffrin, E, Lecoustey, P, Pecquet, A L, Samain, A, and Talvard, M}
abstractNote = {The disruptions are one of the major obstacles to present day tokamaks extrapolation to fusion reactors. We have recently proposed a piloting discharge strategy on TORE SUPRA to prevent density limit disruptions. This strategy is based on the use of the Ergodic Divertor (ED). We have observed that the ED stabilizes the m=2 n=1 tearing mode and that in deuterium discharges limited by the outboard limiter it induces a fast decrease of the plasma density. The piloting strategy is taken in three steps: (1) the approach of the density limit is detected by a threshold on the MHD activity amplitude; (2) the gas puff is switched off; (3) the ED is turned on. Then the m=2 n=1 tearing mode is stabilized the density decreases and the disruption is avoided. This strategy has already been successully tested on about 20 specific deuterium shots with 2.5<4.5 in which the density limit is approached by ramping up the density with gas puffing. In this paper, experimental data are reported and analyzed. First, the principle of the ED and the density limit disruption phenomenology are briefly recalled. Then the ED effect on plasma density, radiated power and MHD activity are analyzed, and the piloting strategy to prevent density limit disruptions is discussed.}
place = {France}
year = {1991}
month = {Dec}
}