Biasing example GB06

Dear experts,

I am playing around with GB06 example and I have two questions.

  1. Simply by executing the code, I get a warning message as follows:
-------- WWWW ------- G4Exception-START -------- WWWW -------
*** G4Exception : BIAS.GEN.28
      issued by : G4BiasingHelper::AddBiasingProcessLimiter(G4ProcessManager* pmanager)
Trying to re-add a G4ParallelGeometriesLimiterProcess process to the process manager for 'neutron (PDG : 2112 ) while one is already present.
Call ignored.

*** This is just a warning message. ***
-------- WWWW -------- G4Exception-END --------- WWWW -------

However it seems the biasing is working based on what I see in the figure so I do not know what it really means. Can I neglect it and why is this happening ?

  1. In this example, I have simply tried to add a scoring mesh as follows:
      // I have also added the scoringmanager

      UImanager->ApplyCommand("/score/create/boxMesh meshScore");
      UImanager->ApplyCommand("/score/mesh/boxSize 500 500 250 cm");
      UImanager->ApplyCommand("/score/mesh/nBin 100 100 50");

      UImanager->ApplyCommand("/score/quantity/cellFlux cfluxg_");
      UImanager->ApplyCommand("/score/filter/particle gammaFilter gamma");
      UImanager->ApplyCommand("/score/quantity/cellFlux cfluxe_");
      UImanager->ApplyCommand("/score/filter/particle elecFilter e-");


When comparing the execution of this example with and without the scoring mesh, it seems the biasing is not taken into account when the scoring is set (see pictures below):

With scoring mesh

Without scoring mesh

Is there an issue between the mesh of the scoring process and the one of the biasing process ? I took care of having different naming convention (parallelWorldForSlices and meshScore).

Anyone having some hints ?