Three-dimensional simulations of plasma turbulence in the RFX-mod scrape-off layer and comparison with experimental measurements

Riva, Fabio Matteo; Vianello, Nicola; Spolaore, Monica; Ricci, Paolo; Cavazzana, Roberto; Marrelli, Lionello; Spagnolo, Silvia

doi:10.1063/1.5008803

Back

Riva_2018_AIP_Three-dimensional simulations

Journal article

Three-dimensional simulations of plasma turbulence in the RFX-mod scrape-off layer and comparison with experimental measurements

Riva, Fabio Matteo ORCID Istituto ricerche solari Aldo e Cele Daccò (IRSOL), Faculty of Informatics, Università della Svizzera italiana Switzerland - Swiss Plasma Center (SPC) , École Polytechnique Fédérale de Lausanne (EPFL), Switzerland
Vianello, Nicola Consorzio RFX (CNR, ENEA, INFN), Università di Padova, Italy
Spolaore, Monica Consorzio RFX (CNR, ENEA, INFN), Università di Padova, Italy
Ricci, Paolo Swiss Plasma Center (SPC) , École Polytechnique Fédérale de Lausanne (EPFL), Switzerland
Cavazzana, Roberto Consorzio RFX (CNR, ENEA, INFN), Università di Padova, Italy
Marrelli, Lionello Consorzio RFX (CNR, ENEA, INFN), Università di Padova, Italy
Spagnolo, Silvia Consorzio RFX (CNR, ENEA, INFN), Università di Padova, Italy

2018

Published in:

Physics of Plasmas. - 2018, vol. 25, no. 2, p. 022305

Plasma properties and parameters

English The tokamak scrape-off layer (SOL) plasma dynamics is investigated in a circular limiter configuration with a low edge safety factor. Focusing on the experimental parameters of two ohmic tokamak inner-wall limited plasma discharges in RFX-mod [Sonato et al., Fusion Eng. Des. 74, 97 (2005)], nonlinear SOL plasma simulations are performed with the GBS code [Ricci et al., Plasma Phys. Controlled Fusion 54, 124047 (2012)]. The numerical results are compared with the experimental measurements, assessing the reliability of the GBS model in describing the RFX-mod SOL plasma dynamics. It is found that the simulations are able to quantitatively reproduce the RFX-mod experimental measurements of the electron plasma density, electron temperature, and ion saturation current density (jsat) equilibrium profiles. Moreover, there are indications that the turbulent transport is driven by the same instability in the simulations and in the experiment, with coherent structures having similar statistical properties. On the other hand, it is found that the simulation results are not able to correctly reproduce the floating potential equilibrium profile and the jsat fluctuation level. It is likely that these discrepancies are, at least in part, related to simulating only the tokamak SOL region, without including the plasma dynamics inside the last close flux surface, and to the limits of applicability of the drift approximation. The turbulence drive is then identified from the nonlinear simulations and with the linear theory. It results that the inertial drift wave is the instability driving most of the turbulent transport in the considered discharges.

Collections