Interchange-turbulence-based radial transport model for SOLPS-ITER: A COMPASS case study

0531650 - ÚFP 2021 RIV DE eng J - Journal Article
Carli, S. - Dekeyser, W. - Coosemans, R. - Dejarnac, Renaud - Komm, Michael - Dimitrova, Miglena - Adámek, Jiří - Bílková, Petra - Böhm, Petr
Interchange-turbulence-based radial transport model for SOLPS-ITER: A COMPASS case study.
Contributions to Plasma Physics. Roč. 60, 5, 6 (2020), č. článku e201900155. ISSN 0863-1042. E-ISSN 1521-3986
R&D Projects: GA MŠMT(CZ) LM2015045
EU Projects: European Commission(XE) 633053 - EUROfusion
Institutional support: RVO:61389021
Keywords : plasma-edge * radial transport * solps-iter * turbulence
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 1.563, year: 2020
Method of publishing: Limited access
https://onlinelibrary.wiley.com/doi/abs/10.1002/ctpp.201900155

Mean-field plasma edge transport codes such as SOLPS-ITER heavily rely on ad-hoc radial diffusion coefficients to approximately model anomalous transport. Such coefficients are experimentally determined and vary between different machines, and also depend on the operational regime and plasma location within the same device. Therefore, to match experimental data the modeller is required to manually tune several free parameters in expensive simulations, and the code's predictive capabilities are significantly downgraded. As a solution, a new model has been developed for SOLPS-ITER, solving an additional transport equation for the turbulent kinetic energy k, derived by consistently time-averaging the Braginskii equations, and including a diffusive closure for the anomalous particle flux. This closure model relates the anomalous diffusion coefficient to the local k value. The resulting equation structure and its closure are inspired by TOKAM2D isothermal interchange turbulence simulation results. Within this model, fewer and hopefully more universal free parameters are retained, thus improving the code's predictive capabilities. The new model has been tested on a COMPASS case for which upstream plasma profiles were available. Experimental data and a reference solution, obtained by matching the profiles through manual tuning of radial diffusivities, have been used to estimate the parameters of our new transport model. A ballooned particle diffusivity profile is retrieved by the new radial transport model, thanks to the proposed interchange drive. The obtained upstream profiles qualitatively agree with the experiment and prove the new model is a promising first attempt to be further refined.
Permanent Link: http://hdl.handle.net/11104/0310267