SOL transport - proposal discussion

Friday 25 Mar 2022, 14:00 → 15:00 Europe/Berlin

zoom room 10: ID: 330-409-3459 / PW: 406184

Valeria Perseo (IPP-Greifswald)

4th meeting to discuss the single proposal planning.

Zoom room 1

1 Proposal: Effect of drifts on SOL transport

Speaker: Matt Kriete

kriete_drift_effects_on_sol_transport_proposal.pptx

discussion on Matt Kriete's proposal
focus on effect of drifts on SOL transport, only/mostly attached plasmas
error field correction for EJM/FTM required
high iota: expected to have weaker drifts thanks to shorter average connection length
2 different powers with 2 different density scans (low to medium, medium to high)
density scans instead of power scans to have more density points
maybe high power - low density possible with small impurity puffing to shield the divertor, but it might be counterproductive
low field could be done in a day, no big changes from the point of view of the coils but the heating schemes will be different and need to be developed
low densities will not be easily available after running high densities, maybe it is better to split the ramp (short program for single densities), the simplest the shot the more easily reproducible they will be
continuous ramp might be good from the point of view of database
TF leader (Ken): propose anything you want, even if it is exotic
TF leader (Carsten): max 20 programs for proposal will be allowed
What about detachment at low field? It could be interesting even within this proposal

2 Proposal: Impurity flow measurements: identification of the thermal force regime

Speaker: Valeria Perseo (IPP-Greifswald)

Perseo_proposal_impurityflows_thermalforce.pptx

discussion on Valeria Perseo's proposal
combination with reversed field (Matt's) and maybe EMC3-Eirene validation (Felix's)
using the same experiment design is good also for reproducibility and probinig different quantities e.g. with spectroscopic diagnostics
include NBI blips for impurity concentration to obtain more data points on thermal force dominance (it should change as well if thermal force dominates)
focus on changing the connection length to minimize drifts and get stronger thermal force?

3 Proposal: Impact of island size on SOL transport

Speaker: Erik Flom

Upstream Characterization and Island Size.pptx

discussion on Erik Flom's proposal
difference of the two approaches (power step down and density steps up) can give information on what is best also for future campaigns
10/10 island chain might need more than -1 kA in Icc, Matthias Otte will provide more info
what about the plasma current? we'll see what we will learn, maybe Yu Gao will deal with fast current saturation or active feedback on control coils to avoid the problem

 

4 Proposals: radiation scaling and stability

Speaker: Gabriele Partesotti

Partesotti_RadiationScaling&Stability.pptx

discussion on Gabriele Partesotti's proposals
radiation scaling and stability
database approach (piggy back) but also dedicated time required with impurity seeding
aim to have all different combinations of seeding and input power possible
radiation stability: increase the concentration at fixed densities is another possible approach, only with fully recycling gasses
radiation scaling should come first to identify good ranges
bifurcation of radiation has not been properly observed up to now, it looks like the ramp can be slowed down without running into the bifurcation