Geant4 User's Guide for Application Developers - Geant4 - CERN

Detector Definition and Response• appraise particle quantities related to special regions or surfaces,• be applicable to all "cells" (physical volumes or replicas) of a given geometry,• be customizable.Standard scoring must be provided for quantities such as tracks entering a cell, average weight of entering tracks,energy of entering tracks, and collisions inside the cell.A number of scorers have been created for this specific appliction:G4PSNofCollisionThis scorer records the number of collisions that occur within a scored volume/cell. There is the additionalpossibility to take into account the track weight whilst scoring the number of collisions, via the followingcommand:G4PSNofCollision* scorer1 = new G4PSNofCollision(psName="CollWeight");scorer1->Weighted(true);G4PSPopulationThis scores the number of tracks within in a given cell per event.G4PSTrackLengthThe track lengths within a cell are measured and if, additionally, the result is desired to be weighted then thefollowing code has to be implemented:G4PSTrackLength* scorer5 = new G4PSTrackLength(psName="SLW");scorer5->Weighted(true);Further if the energy track flux is required then the following should be implemented:G4PSTrackLength* scorer6 = new G4PSTrackLength(psName="SLWE");scorer6->Weighted(true);scorer6->MultiplyKineticEnergy(true);MFDet->RegisterPrimitive(scorer6);Alternatively to measure the flux per unit velocity then:G4PSTrackLength* scorer7 = new G4PSTrackLength(psName="SLW_V");scorer7->Weighted(true);scorer7->DivideByVelocity(true);MFDet->RegisterPrimitive(scorer7);Finally to measure the flux energy per unit velocity then:G4PSTrackLength* scorer8 = new G4PSTrackLength(psName="SLWE_V");scorer8->Weighted(true);scorer8->MultiplyKineticEnergy(true);scorer8->DivideByVelocity(true);MFDet->RegisterPrimitive(scorer8);4.5. Digitization4.5.1. DigiA hit is created by a sensitive detector when a step goes through it. Thus, the sensitive detector is associated tothe corresponding G4LogicalVolume object(s). On the other hand, a digit is created using information of hits and/or other digits by a digitizer module. The digitizer module is not associated with any volume, and you have toimplicitly invoke the Digitize() method of your concrete G4VDigitizerModule class.Typical usages of digitizer module include:• simulate ADC and/or TDC135