Multimachine Simulations of Dhrertor Pumping and its Dependency on Target Geometry and Plasma Conditions

摘要

The differences in the reported results for the dependency of the divertor plenum neutral pressure on strike point position can be understood and reproduced when the divertor pumping geometry is taken into account. While the plenum pressure in Dlll-D is dominated by direct scattering of neutrals into the pumping slot, in JET and C-mod is dominated by multiply scattered neutrals. This results in a less critical dependency of divertor pumping on the exact position of the strike point.