Comparison between liquid lithium and liquid tin targets in reactor relevant conditions for DEMO and I-DTT

The performance of divertor targets made of liquid metal, either lithium or tin, in highly powered tokamaks is analyzed for the proposed European DEMO and the projected Italian divertor test tokamak (I-DTT). The main tool is the 2D edge code TECXY, together with COREDIV. The results show that both materials are compatible with either DEMO or I-DTT under proper setting of the liquid divertor parameters. In general, operation at a high density is always highly recommended especially if detached conditions are desired. The latter can always be closely approached even when preserving an acceptable plasma purity with a proper setting of the target parameters and with the help of an additional impurity, which is able to radiate significantly inside the scrape-off layer plasma. For this action, Ar is preferred over Ne. Tin usually performs better than lithium for mitigation properties, reducing plasma pollution, material consumption, which in a DEMO-like device could be very high, and a definitely lower chemical affinity to hydrogen.