Analysis of particle pumping using SOLDOR/NEUT2D code in the JT-60U tokamak

In order to understand the particle pumping on JT-60U, we analyze the roles of atomic and molecular processes using SOLDOR/NEUT2D code. A case of short strike point distance shows that most of neutrals produced on the targets go toward the exhaust slot directly. Whereas, neutrals are scattered in the spherically at random for the long distance case by collision processes and a few of them go toward the slot. It is clarified that the incident neutrals to the slot at low n(e)/high T-e divertor plasma condition are dominated by atoms. Those at high n(e)/low T-e condition are dominated by molecules due to elastic collision. (C) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.