Boundary Conditions - Presheath vs Vacuum

SPIS
1

I’ve been reading some papers surrounding cold plasma measurements and SPIS modelling, and in them the authors were able to recreate presheath conditions to more accurately model boundary conditions (BC) in dense plasma. I’m using SPIS 6.2.6, and in the documentation it seems to point to a global parameter called “poissonBCType” however, it is not in the current version.

I have found settings within the Group Editor, under the external boundary group for plasma, mainly “BdFourAlpha” and I figured it may be the BC for the potential approx. 1/r^(alpha). Is this the correct setting when it comes to presheath and vacuum BCs? Are there other settings/global parameters that I should know to accurately define this?

2

Hi Joseph. Even if the global parameter isn’t in the default parameter list, it can still be read and parsed. set poissonBCType to whatever you want, and it works in SPIS 6.2.6. BdFourAlpha is not something I’m familiar with