IMPURITY PRODUCTION AND TRANSPORT PROCESSES IN DIVERTOR REGIONS

2D modelling of the ITER divertor with a lithium target are presented as the first step in the validation of a new divertor concept, based o n the capillary structure applied for the cooling of the divertor plat es by the evaporation of lithium. The lithium radiative divertor scena rio has been examined for the ITER using the DDIC95 code. This code ha s been specially produced to simulate the behavior of the main plasma and that of impurities, at their arbitrary densities in a real diverto r geometry. The self-consistent simulation of a background plasma, neu tral gas and impurities is a specific feature of this code. First calc ulations have shown that the thermal loads on the divertor plates are reduced to 1 MW/m(2). The main power entering the divertor is radiated on the baffles in the divertor. The longitudinal and radial distribut ions of lithium neutral and ion density are presented in this paper. T he lithium flux through the magnetic line near the separatrix and Z(ef f) in the main plasma are estimated. On the basis of the 1D code the f usion plasma parameters inside the separatrix and the values of lithiu m flow through the separatrix at which the self-sustaining D-T reactio n takes place have been calculated. (C) 1997 Elsevier Science B.V.