A numerical study of CX and radiation losses in a divertor channel

A new 2-dimensional code, EDGE2D/N, has been set up to investigate the physics of a simple divertor configuration. The aim is not model validation by means of detailed simulations of particular shots but rather the study of basic physics phenomena playing a role in the divertor. Special interest is given to the relative importance of transport, power losses due to hydrogenic atomic processes (charge-exchange (CX) and ionization) and hydrogen radiation in divertor relevant plasma regimes. In particular we analyse quantitatively the relevance of hydrogen atomic losses, following the ideas of Rebut and Watkins. Calculations for JET as well as for ITER relevant cases have been performed. (author) 2 refs., 4 figs., 4 tabs