Scintillation photons are not produced

Geometry, Fields and Transportation
1

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Geant4 Version: 11.3.0
Operating System: Windows 11
Compiler/Version: VS 2026
CMake Version: 4.2.1

Hi all. My simulation is run perfectly but i cant get any scintillation photon. However, i have Cerenkov photons.What i think that the problem is in table properties of material. This is properties of material.

```

 G4MaterialPropertiesTable* BC408MPT = new G4MaterialPropertiesTable();

 std::vector<G4double> energy = { 7.385 * eV, 7.480 * eV, 7.756 * eV, 8.100 * eV, 8.351 * eV, 8.444 * eV, 8.543 * eV, 8.875 * eV };
 std::vector<G4double> rindex = { 1.497, 1.499, 1.504, 1.508, 1.514, 1.517, 1.520, 1.526 };
 std::vector<G4double> absorp = { 2.1213* mm, 1.5967 * mm, 1.5965 * mm, 1.2875 * mm, 0.6180 * mm, 0.3562 * mm, 0.2060 * mm, 0.0824 * mm };
 std::vector<G4double> scint = { 0.0, 0.111, 0.278, 0.556, 0.889, 1.000, 0.833, 0.0 };

 
 BC408MPT->AddProperty("RINDEX", energy, rindex, true);
 BC408MPT->AddProperty("ABSLENGTH", energy, absorp, true);
 BC408MPT->AddProperty("SCINTILLATIONCOMPONENT1", energy, scint,true);
 BC408MPT->AddProperty("SCINTILLATIONCOMPONENT2", energy, scint, true);
 BC408MPT->AddConstProperty("SCINTILLATIONYIELD", 10000.0 / MeV, true);
 BC408MPT->AddConstProperty("RESOLUTIONSCALE", 1.0, true);
 BC408MPT->AddConstProperty("SCINTILLATIONTIMECONSTANT1", 1.0 * ns, true);
 BC408MPT->AddConstProperty("SCINTILLATIONTIMECONSTANT2", 10.0* ns, true);
 BC408MPT->AddConstProperty("SCINTILLATIONYIELD1", 0.8, true);
 BC408MPT->AddConstProperty("SCINTILLATIONYIELD2", 0.2, true);

 fBC408Material->SetMaterialPropertiesTable(BC408MPT);
 fBC408Material->GetIonisation()->SetBirksConstant(0.126 * mm / MeV);

I use example OpNovice to set the properties. Any Ideas ?

2

Hello @Al_Harith

I think your material properties table is mostly correct, but scintillation photons are produced only if all required conditions are true.

Note: without G4OpticalPhysics, no scintillation photons will ever be produced.

Also, check that your energy spectrum is correct and within a realistic range.

Good luck.

Hasan Ghotme

3

Thanks Hasan
I used G4OpticalPhysics correctly (I have Cerenkov Photons). what are the required conditions ?