Type II ELMy H modes on ASDEX Upgrade with good confinement at high density

摘要

H modes with good confinement and small ELMs with the characteristics of type II or grassy ELMs have been observed on ASDEX Upgrade. Such an ELM behaviour is essential to minimize erosion of the divertor tiles in any next step device. For the first time, operation with this favourable ELM type could be demonstrated close to the Greenwald density. Even for such high densities, energy Confinement times were close to recent H modes scalings.