geant4如何定义光电倍增管

G4OpticalPhysics* opticalPhysics = new G4OpticalPhysics();
RegisterPhysics( opticalPhysics );
opticalPhysics->SetWLSTimeProfile("delta");
opticalPhysics->SetScintillationYieldFactor(1.5);
opticalPhysics->SetScintillationExcitationRatio(0.);

opticalPhysics->SetMaxNumPhotonsPerStep(100);
opticalPhysics->SetMaxBetaChangePerStep(10.0);

opticalPhysics->SetTrackSecondariesFirst(kCerenkov，true);
opticalPhysics->SetTrackSecondariesFirst(kScintillation，true);