Helium an neon enrichment studies in the JET mark IIAP and mark IIGB divertors

摘要

Adequte helium enrichment and exhaust have been achieved in reactor relevant ELMy H mode plasmas in JET performed in the Mark II divertor geometry. These quantities, describing the retention of impurities in divertors, have been experimentally inferred from CXRS measurements in the core plasma, and from a spectroscopic analysis of a Penning gauge discharge in the exhaust gas. The retention of helium was found to be sufficient with respect to the requirements in a next step device, with helium enrichment factors exceeding 0.1 in high density ELMy H mode discharges.