Modelling of the TCV Power EXhaust (PEX) upgrade
ORAL
Abstract
The Tokamak à Configuration Variable (TCV) has recently undergone a major upgrade of its plasma-facing components, divertor, and edge-plasma diagnostics. The installation of removable gas baffles allows for variable divertor closure and has demonstrated power exhaust mitigation with increased closure. This upgrade provides a unique and well-diagnosed environment to challenge and validate the numerical models used in the design of fusion reactors.
The reference Power EXhaust (PEX) experiment, a lower single-null ohmic density ramp with IP = 250 kA and a reverse BΦ = 1.4 T, is systematically modelled using the SOLPS-ITER edge-plasma code suite. The upstream electron density is scanned across all baffled and unbaffled configurations. For the first time in TCV, input fluxes at the core boundary of the SOLPS domain, anomalous diffusivities, and pinch velocities are evaluated from core-edge integrated modelling, informed by the TGLF code. The work investigates the role of core and divertor target boundary conditions, radial pinch velocities, carbon sources and fluid flux limiters. It explains the divertor density overestimation previously found in TCV edge simulations. As divertor closure increases, the improved exhaust properties observed in experiments are well replicated by simulations. The constraints provided by integrating edge and core modelling and the newly available diagnostic data have significantly enhanced the ability of the model to quantitatively reproduce experimental results.
The reference Power EXhaust (PEX) experiment, a lower single-null ohmic density ramp with IP = 250 kA and a reverse BΦ = 1.4 T, is systematically modelled using the SOLPS-ITER edge-plasma code suite. The upstream electron density is scanned across all baffled and unbaffled configurations. For the first time in TCV, input fluxes at the core boundary of the SOLPS domain, anomalous diffusivities, and pinch velocities are evaluated from core-edge integrated modelling, informed by the TGLF code. The work investigates the role of core and divertor target boundary conditions, radial pinch velocities, carbon sources and fluid flux limiters. It explains the divertor density overestimation previously found in TCV edge simulations. As divertor closure increases, the improved exhaust properties observed in experiments are well replicated by simulations. The constraints provided by integrating edge and core modelling and the newly available diagnostic data have significantly enhanced the ability of the model to quantitatively reproduce experimental results.
*This work has been carried out within the framework of the EUROfusion Consortium, partially funded by the European Union via the Euratom Research and Training Programme (Grant Agreement No 101052200 — EUROfusion). The Swiss contribution to this work has been funded by the Swiss State Secretariat for Education, Research and Innovation (SERI). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union, the European Commission or SERI. Neither the European Union nor the European Commission nor SERI can be held responsible for them.
–
Publication: E. Tonello et al, Modelling of the TCV Power EXhaust (PEX) upgrade (planned).
Presenters
-
Elena Tonello
- École Polytechnique Fédérale de Lausanne