Study of particle pumping characteristics for different pumping geometries in JT-60U and DIII-D divertors

摘要

Particle pumping characteristics were compared between pumping from the inner side private flux region (IPP) and pumping from both sides of the private flux region (BPP) in the JT- 60U W shaped divertor, and between JT-60U IPP and pumping in the DIII-D lower baffled divertor. The pumping flux for BPP is smaller than that for IPP by about a factor of 2 with weak in-out Asymmetry of recycling neutral flux and by a factor of 3.5-6.5 with strong in -out asymmetry. The Reduction of the pumping flux for BPP is consistent with Monte Carlo simulation, where backflow at The outer pumping slot is observed due to in-out recycling asymmetry.