see https://gitlab.mpcdf.mpg.de/ygao/emc3_lite_universal/-/issues/1
Email B. Davies, 26.11.2023:
• Amit, Yühe and I have gone through the code and found the bit in which the cells-behind-the-targets are labelled "inaccessible"
• The "simplest fix" is simply to remove this section of code, or to make it optional (by means of a flag in the input file.) The thing to worry about is, whether this leads to any undesirable side effects. From our discussions, there were no obvious such effects.
• Amit has implemented this "simplest fix" and tested it on his O-point divertor (which was previously exhibiting an "inaccessible cells" problem). When running the connection length subroutine, we see that the previously "inaccessible" region is no longer inaccessible (good news). However, there's a couple of curious features in the connection length plot, which we need to think about further (bad news). I think there's also a few other tests/diagnostics we can perform to make sure things are behaving as expected.
• To keep all the documentation and discussion of this in one place, I'll make an "issue" on the Gitlab project, so everybody can see it and chip in.
