Impact of fast ions on density peaking in JET: fluid and gyrokinetic modeling
Artikel i vetenskaplig tidskrift, 2019

The effect of fast ions on turbulent particle transport, driven by ion temperature gradient (ITG)/trapped electron mode turbulence, is studied. Two neutral beam injection (NBI) heated JET discharges in different regimes are analyzed at the radial position rho(t) = 0.6, one of them an L-mode and the other one an H-mode discharge. Results obtained from the computationally efficient fluid model EDWM and the gyro-fluid model TGLF are compared to linear and nonlinear gyrokinetic GENE simulations as well as the experimentally obtained density peaking. In these models, the fast ions are treated as a dynamic species with a Maxwellian background distribution. The dependence of the zero particle flux density gradient (peaking factor) on fast ion density, temperature and corresponding gradients, is investigated. The simulations show that the inclusion of a fast ion species has a stabilizing influence on the ITG mode and reduces the peaking of the main ion and electron density profiles in the absence of sources. The models mostly reproduce the experimentally obtained density peaking for the L-mode discharge whereas the H-mode density peaking is significantly underpredicted, indicating the importance of the NBI particle source for the H-mode density profile.

fluid

particle transport

fast ions

gyrokinetic

Författare

Fredrik Eriksson

Chalmers, Fysik, Material- och ytteori

Michael Oberparleiter

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Plasmafysik och fusionsenergi

Andreas Skyman

Chalmers, Rymd-, geo- och miljövetenskap, Mikrovågs- och optisk fjärranalys, Global miljömätteknik och modellering

Hans Nordman

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Plasmafysik och fusionsenergi

Pär Strand

Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik, Plasmafysik och fusionsenergi

Antti Salmi

Teknologian Tutkimuskeskus (VTT)

Tuomas Tala

Teknologian Tutkimuskeskus (VTT)

Plasma Physics and Controlled Fusion

0741-3335 (ISSN) 1361-6587 (eISSN)

Vol. 61 7 075008

Ämneskategorier

Annan fysik

Strömningsmekanik och akustik

Fusion, plasma och rymdfysik

DOI

10.1088/1361-6587/ab1e65

Mer information

Senast uppdaterat

2019-11-19