Key impact of finite-beta and fast ions in core and edge tokamak regions for the transition to advanced scenarios

TitleKey impact of finite-beta and fast ions in core and edge tokamak regions for the transition to advanced scenarios
Publication TypeJournal Article
Year of Publication2015
AuthorsJ. Garcia, C. Challis, J. Citrin, H. Doerk, G. Giruzzi, T. Görler, F. Jenko, P. Maget, JET Contributors
JournalNuclear Fusion
Volume55
Issue5
Pagination053007
Abstract

Extensive linear and non-linear gyrokinetic simulations and linear magnetohydrodynamic (MHD) analyses performed for JET hybrid discharges with improved confinement have shown that the large population of fast ions found in the plasma core under particular heating conditions has a strong impact on core microturbulence and edge MHD by reducing core ion heat fluxes and increasing pedestal pressure in a feedback mechanism. In the case of the ITER like wall, it is shown how this mechanism plays a decisive role for the transition to plasma regimes with improved confinement and it can explain the weak power degradation obtained in dedicated power scans. The mechanism is found to be highly dependent on plasma triangularity as it changes the balance between the improvement in the plasma core and the edge. The feedback mechanism can play a similar role in the ITER hybrid scenario as in the JET discharges analysed due to its high triangularity plasmas and the large amount of fast ions generated in the core by the heating systems and the alpha power.

URLhttp://www.iop.org/Jet/article?EFDP13061&EFDP13061
DOI10.1088/0029-5515/55/5/053007
Division

FP

Department

CPP-HT

PID

cb08bcfe1152e2a818b87b6c975ced7e

Alternate TitleNucl. Fusion
LabelOA
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