|Message: Photonuclear with Bertini in g4.10.00.p01||Not Logged In (login)|
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Hi, I'm new to G4 and I'm trying to use it to study nuclear reactions, especially the photodisintegration of light nuclei at low energies.
I read that this topic is rather new for Geant and not everything works 100%.
Anyway I used example Hadr03 as a starting point with:
G4ProcessManager* pManager = G4Gamma::Gamma()->GetProcessManager(); // G4PhotoNuclearProcess* process = new G4PhotoNuclearProcess(); process->BiasCrossSectionByFactor(1000000000); // G4CascadeInterface* bertini = new G4CascadeInterface(); bertini->SetMaxEnergy(10*GeV); process->RegisterMe(bertini); // pManager->AddDiscreteProcess(process);
to study 24Mg(gamma,alpha)20Ne reaction at 11MeV.
So I run a 11MeV gamma beam on a Mg24 target but unfortunately I only get neutrons and protons (the latter only with slightly higher gamma energy) but no alphas until some 20ish MeV where everything is ok and correct Q-Value is also printed in the summary at the end of the run. I tried to go deep into G4CascadeInterface() but it's very complicated and unclear to me which models and classes handle the whole process. I suspect it might be related to some other threshold or internal check, maybe something with the CoulombBarrier but it's just a guess and so far no workaround solved it.
Can someone please provide some useful information about classes and methods involved in the process I want to study? Am I doing something wrong? Does anyone work with these classes and/or did develop some new code? Any other suggestion would be very appreciated!
note: I hacked into the code and implemented the BiasCrossSectionByFactor method for G4PhotoNuclearProcess (it couldn't find the method, I just copied it from ), and changed the threshold energy by considering alpha emission in calculation, by replacing the return value of G4PhotoNuclearCrossSection::ThresholdEnergy as:
return (dA < dP ? (dA < dN ? dA : dN) : (dP < dN ? dP : dN));
where dA is related to alpha emission. And that provided the first neutrons out of the target.
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