Simulation code for the D- beam transport through the ITER neutralizer

This paper reports the first results on the negative ions beam transport through the ITER neutralizer by the recently developed numerical tool OBI-2 (Orsay Beam Injector, two dimensional code) based on the Particle-in-Cell approach coupled with the Monte Carlo treatment of collisions. The choice of the elementary processes involved in the D(-) / D(2) interaction are discussed as well as the related plasma/wall processes. The latter dominates over the interaction between particles composing the residual weakly ionized plasma. The formation of the residual plasma is demonstrated and its role on the beam transport is emphasized.