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arXiv · 1310.8433

Impact of nitrogen seeding on confinement and power load control of a high-triangularity JET ELMy H-mode plasma with a metal wall

C Giroud·G P Maddison·S Jachmich·F Rimini·M N A Beurskens·I Balboa·S Brezinsek·R Coelho·J W Coenen·L Frassinetti·E Joffrin·M Oberkofler·M Lehnen·Y Liu·S Marsen·K McCormick K·A Meigs·R Neu·B Sieglin·G van Rooij·G Arnoux·P Belo·M Brix·M Clever·I Coffey·S Devaux·D Douai·T Eich·J Flanagan·S Grunhagen·A Huber·M Kempenaars·U Kruezi·K Lawson·P Lomas·C Lowry·I Nunes·A Sirinnelli·A C C Sips·M Stamp·S Wiesen·JET-EFDA contributors
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Abstract

This paper reports the impact on confinement and power load of the high-shape 2.5MA ELMy H-mode scenario at JET of a change from an all carbon plasma facing components to an all metal wall. In preparation to this change, systematic studies of power load reduction and impact on confinement as a result of fuelling in combination with nitrogen seeding were carried out in JET-C and are compared to their counterpart in JET with a metallic wall. An unexpected and significant change is reported on the decrease of the pedestal confinement but is partially recovered with the injection of nitrogen.

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C Giroud, G P Maddison, S Jachmich, F Rimini, M N A Beurskens, I Balboa, S Brezinsek, R Coelho, J W Coenen, L Frassinetti, E Joffrin, M Oberkofler, M Lehnen, Y Liu, S Marsen, K McCormick K, A Meigs, R Neu, B Sieglin, G van Rooij, G Arnoux, P Belo, M Brix, M Clever, I Coffey, S Devaux, D Douai, T Eich, J Flanagan, S Grunhagen, A Huber, M Kempenaars, U Kruezi, K Lawson, P Lomas, C Lowry, I Nunes, A Sirinnelli, A C C Sips, M Stamp, S Wiesen, JET-EFDA contributors. 2013-10-31. Impact of nitrogen seeding on confinement and power load control of a high-triangularity JET ELMy H-mode plasma with a metal wall. https://doi.org/10.1088/0029-5515/53/11/113025

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