Advanced Tokamak scenarios, scientific discussion

The working group on 'Advanced Tokamak scenarios' will discuss observations and (preliminary) results related to the reproducibility of the ramp-up of the scenarios used for our Advanced Tokamak studies, which we obtained during the first months of the ongoing campaign.

The 2019 discharges were hardly reproducible in 2020 and a significant number of discharges of the high level topic was to dedicated to study these reproducibility issues.

We plan to present the material in 3 or 4 short contributions.

The overall topic is the plasma confinement at the beginning of the high beta phase depending on
- initial fueling wave form (and control)
- He-concentration which we also could characterise with the help of the new pedestal diagnostics for smaller Raus

We can now reproducibly obtain phases with identical beta but significantly different heating power which we started to analyse with respect to some suspects:
- q-profile variation during/shortly after L-H transition
- divertor performance
- pedestal effects

We hope for the critical input of all interested colleagues to the discussions following the presentations.

At this stage, we will not discuss the current profile evolution during the flat top phase which is the next step of experiments and analysis.