Bachelor Thesis: Modeling of neutral particle transport at the W7-X divertor with COMSOL (25+Questions)

• Markus Grasser (IPP Bereich Greifswald)

This thesis presents a simplified model of the neutral particle transport at the divertor of the Wendelstein 7-X stellarator. The model uses the angular coefficient method implemented in the commercial software COMSOL Multiphysics to calculate the neutral particle transport as a free molecular flow. The location of the neutral particle origin is derived by coupling the simulation to the plasma edge code EMC3-Lite. The presented simulation is capable of quantifying the amount of reionised particles, the particle flux entering the sub-divertor region and the contribution of different wall components to the neutral particle transport in a few CPU minutes. A preliminary validation of the simulation shows that the results are comparable to experimental and EMC3-Eirene values.