Impurity radiation in DEMO systems modelling

摘要

For fusion reactors with ITER divertor technology, it will be imperative to significantly reduce the heat flux into the divertor e.g. by seeded impurity radiation. This has to be done without affecting the accessibility of a high performance scenario. To assess the implications of seeded plasma impurities on DEMO design, we have developed an impurity radiation model for radiation inside the separatrix. Evaluating the validity of our model, we find the assumption of a local ionisation equilibrium to be appropriate for our purposes and the assumption of flat impurity profiles - even though not satisfactory - to represent the best currently possible. Benchmarking our model against other codes highlights the need to use up to date atomic loss function data.