Re: simultaneous B and E fields

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Sorry, I gave the wrong advise! This constructor does NOT exist:

> new G4ElectroMagneticField(gbl_Bfield_x, gbl_Bfield_y, gbl_Bfield_z,
                           lcl_Efield_x, lcl_Efield_y, lcl_Efield_z);

Maybe, it should, to make life easy for situations with both a constant B and E field; or a class G4UniformElectroMagneticField.

Unfortunately, there is no example in /examples/extended/field that would show you how to go about this. The only example I found (but I didn't check/follow the code in detail) that might give you hints of what to do is:

/examples/advanced/microbeam/

where the MicrobeamEMField inherits from G4ElectroMagneticField. You now can write a constructor for 'your field class' with the above signature to initialize both constant B and E fields.

Also note, you MUST NOT get a new local field manager from:

  G4FieldManager* fLocalFieldManager = G4TransportationManager::GetTransportationManager()->GetFieldManager();

and then set:

  fLocalFieldManager->SetDetectorField(fLocalField);

This will just assign the fLocalField to the World (GlobalFieldManager which is what the G4TransporationManager returns) and hence replace the fGlobalField.

What you need to do is actually make a new FieldManager with:

fLocalFieldManager = new G4FieldManager();

Note, that the examples/field/field03 has this correct only since the G4.9 release.