Cross section biasing by region

Hi, I would like to use cross section biasing in only one region of my problem. I have searched the forum and seen the question asked in related ways before, but none were answered well. I am using the latest Geant4 v11.2.2.

It appears the G4EmExtraParameters::ActivateForcedInteraction and ::ActivateSecondaryBiasing have region arguments, but ::SetProcessBiasingFactor does not.

I also tried to familiarize myself with the biasing methods provided by the G4VBiasingOperator and the implemented operations in the source/processes/biasing/generic/include directory. The G4BOptnChangeCrossSection comes the closest to what I want, but does not have the same feature of choosing one proportional constant by which to amplify the cross section values and subsequent weighting, but rather seems to take single cross sections values only.

Is there a way to accomplish what the G4EmExtraParameters::SetProcessBiasing factor does globally, but only in a specifc region (or better yet, region as specified by a parallel geometry)?

Another thread(Use different physics list per volume/material) mentioned splitting up the simulation. This is not an option for me, because I am using complicated mesh geometries that would exceed the size of my second simulation


Pinging @marcverderi and @semenjuk for their input.

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