EMC3–EIRENE simulations of neon impurity seeding effects on heat flux distribution on CFETR

Abstract

The numerical modelling of the heat flux distribution with neon impurity seeding on China fusion engineering test reactor has been performed by the three-dimensional (3D) edge transport code EMC3–EIRENE. The maximum heat flux on divertor targets is about 18 MW m−2 without impurity seeding under the input power of 200 MW entering into the scrape-off layer. In order to mitigate the heat loads below 10 MW m−2, neon impurity seeded at different poloidal positions has been investigated to understand the properties of impurity concentration and heat load distributions for a single toroidal injection location. The majority of the studied neon injections gives rise to a toroidally asymmetric profile of heat load deposition on the in- or out-board divertor targets. The heat loads cannot be reduced below 10 MW m−2 along the whole torus for a single toroidal injection location. In order to achieve the heat load mitigation (<10 MW m−2) along the entire torus, modelling of sole and simultaneous multi-toroidal neon injections near the in- and out-board strike points has been stimulated, which indicates that the simultaneous multi-toroidal neon injections show a better heat flux mitigation on both in- and out-board divertor targets. The maximum heat flux can be reduced below 7 MW m−2 on divertor targets for the studied scenarios of the simultaneous multi-toroidal neon injections.