AliReconstruction will store in the AliESDRun the average intensities for interacting and nonintercting bunches: const AliESDRun* esdRun = esdEvent->GetESDRun(); double x = esdRun->GetMeanIntensityIntecting(int beamID); double y = esdRun->GetMeanIntensityNonIntecting(int beamID); -1 on return means missing info.
ESD can init the Bfield via AliESDRun::InitMagneticField() 1) Added currents/beam info to AliESDRun and the method to AliESDRun::InitMagneticField() (+ alias AliESDEvent::InitMagneticField()) 2) AliReconstruction will fill needed Bfield info in AliESDRun 3) AliMagF got a "static CreateFieldMap" to create a map from the currents. All classes which create the field (AliGRPManager, AliReconstruction, AliESDRun) will use this method