Plasma influx from the outer wall boundary due to ExB drifts about uedge

[holm10]

Could you provide a link to an example in the code where the ExB flux is implemented @ganjinzero1 ? Having a few places in the code to start looking at would be a good starting point.

I assume this is part of boundary.m, part of the 'divergence-free' terms we previously discussed, correct? I have implemented a proposed fix for the divergence-free terms on the core boundary here: https://github.com/holm10/UEDGE/tree/fniycbo_netzero I am, however, not sure if the same logic can be applied to the other boundaries, but we could discuss this in more detail at some point.

[ganjinzero1]

Yes definitely, I will summarize it with some plots from the KSTAR runs. It is a bit different from the core flux (but may be essentially similar). This seems to be caused by strong poloidal gradients in the far SOL near the outer target plate which will introduce plasma influx due to E_pol x B_tor at the outer wall boundary assuming a forward B configuration. Since ExB flows connect the inner and outer divertor, this plasma influx sometime could enhance the plasma outflow at the HFS outer wall boundary near the inner target plate (enhancing neutral recycling basically). Probably I can talk about it in one of our upcoming Steering group meetings when we come to this item:)

[ganjinzero1]

As we discussed in our USG meeting, we would like to further investigate this problem, probably together with the core and plate boundary conditions as well.

Just put a note here so that I can come back here to complete this issue once we have some agreements.