Dear geant4 users:
I have a simulation setup where a gold box is enclosed within a carbon box and irradiated with 150 keV photons. My goal is to track the angular distribution and kinetic energy of fluorescence photons that are generated within the gold material. Specifically, I am interested in the photons that exit from the gold into the carbon box, and then subsequently exit from the carbon into the world volume.
Below is a snippet from my SteppingAction.cc file:
// --------1) Mark fluorescence photons created in gold volume
if (creatorProcess && creatorProcess->GetProcessName() == "phot" && preVolName == "gold_box" && track->GetParentID() > 0) {
gold_FluoPhotons[trackID] = true;
}
// --------2) Fluorescence photon exiting gold_vol into carbon volume -
//
if (preVolName == "gold_box" && postVolName == "carbon_box" && gold_FluoPhotons.count(trackID)) {
passedToCarbon_Fluo[trackID] = true; // fluorescence photons passed to carbon_vol
G4double Fluo_KE1 = track->GetKineticEnergy() / keV; // KE of Fluorescence photons exiting gold to world
G4ThreeVector fluoDir = track->GetMomentumDirection();
G4double thetaDeg = ComputeThetaDeg(fluoDir);
analysisManager->FillH1(1, thetaDeg);
analysisManager->FillH1(2, Fluo_KE1);
analysisManager->AddNtupleRow();
}
// -------3) Fluorescence photon exiting carbon volume into world volume
if (preVolName == "carbon_box" && postVolName == "world" && gold_FluoPhotons.count(track->GetTrackID()) && passedToCarbon_Fluo.count(track->GetTrackID())) {
G4ThreeVector scatteredDir = track->GetMomentumDirection();
G4double thetaDeg = ComputeThetaDeg(scatteredDir);
G4double Fluo_KE2 = track->GetKineticEnergy() / keV; // KE of Fluorescence photons exiting carbon_vol into world
analysisManager->FillH1(3, thetaDeg);
analysisManager->FillH1(4, Fluo_KE2);
analysisManager->AddNtupleRow();
// cleanup
gold_FluoPhotons.erase(track->GetTrackID());
passedToCarbon_Fluo.erase(track->GetTrackID());
}
}
Problem:
The Fluo_KE1 and Fluo_KE2 variables are recording photons with energies exceeding the gold Kβ line (~80.150 keV). However, I am specifically aiming to track only characteristic X-rays (CXR) emitted from the gold.
Questions:
Why are Fluo_KE1 and Fluo_KE2 registering photons with energies higher than the gold Kβ line?
Am I unintentionally tracking other photon types in addition to CXR?
Any insights or suggestions would be greatly appreciated. Thank you for your support.
Best Regrads,
A.H.
_Geant4 Version: geant4-11-03-patch-02
_Operating System: Ubuntu
_Compiler/Version: gcc/11.4.0
_CMake Version: 3.19.4
