Speaker
Description
With the transition to full tungsten (W) plasma-facing components in ITER, the modeling of plasma wall interaction and the prediction of W erosion, transport and screening it has become a crucial issue for preparing ITER operation. In this context the development of improved modeling tools able to predict W behavior and its impact on plasma performances as well as the transport of seeded impurities is decisive. In this contribution we will report recent results obtained with 3D simulations using the SOLEDGE3X-ERO2.0 workflow, with application and validation on WEST plasma experiments. We have considered realistic 3D magnetic equilibria in WEST where the impact of magnetic ripple requires a fully 3D treatment of the problem, with relatively important variation of the magnetic field in the toroidal direction. Computing W erosion and migration with ERO2.0 on the 3D SOLEDGE3X plasma backgrounds, we are able to reproduce the 3D patterns of erosion on the WEST divertor, that follow the heat flux patterns with maxima and minima periodically spaced on the two sides of the divertor. Using such 3D plasma backgrounds and considering Lower Single Null configuration, the results previously obtained using 2D axisymmetric simulations are revisited. The lower divertor is an important source of W but well screened, even if the 3D cases seem to suggest that the screening is less efficient than what previously obtained with axisymmetric assumption. Interestingly very low erosion rate on the upper divertor is found accordingly with experiments and contrary to what obtained with 2D axisymmetric simulations. Other important contributors to W migration toward core region are the baffle, as expected and predicted also with axisymmetric assumption, and the antenna limiter, as shown in recent 3D studies. These numerical results are compared with analytical models for erosion rates as well as experimental findings from visible spectroscopy and recent post mortem analyses, showing very good agreement and indicating the relevance of having fully 3D geometry description in order to catch W erosion patterns and migration paths. The validation of SOLEDGE3X-ERO2.0 workflow on WEST experiments is a crucial step in order to apply such workflow to ITER relevant scenarios and predict the impact of wall erosion on plasma operation.