Created attachment 9 [details] an example of wrong energy distribution of fission neutrons When using a neutron HP model, we get some fission neutrons (prompt and delayed) with energies around 20 MeV which doesn't seem to agree with experiments. The energy distribution of one example case is attached.
(In reply to comment #0) > Created an attachment (id=9) [details] > an example of wrong energy distribution of fission neutrons > > When using a neutron HP model, we get some fission neutrons (prompt and > delayed) with energies around 20 MeV which doesn't seem to agree with > experiments. The energy distribution of one example case is attached. > Currently, export control restrictions prevent us from making detailed improvements to the fission models. We are in the process of making alternative models which perform better and avoid the above restrictions. Until they are ready you could try the LLNL fission model. In your physics list add: G4HadronFissionProcess *theFissionProcess = new G4HadronFissionProcess(); G4FissLib* theFissionModel = new G4FissLib; theFissionProcess->RegisterMe(theFissionModel); pmanager->AddDiscreteProcess(theFissionProcess);
Hello, thank you for reply. From the first look your explaination is reasonable. I can understand why isotopes are not modeled by neutron HP model (it's discussed in .hh file), but it's very strange about fission neutrons eneries. Neutron HP model manages to give ALMOST RIGHT energy distribution except 20 MeV region. In this case it will not be very hard to compare the Geant 4 results with experiment ones and to edit 20 MeV peak energy neutrons (to change their energies on the fly). Perhaps, I could do it myself, but I would like Geant to improve for all others. Additionally, we are making calculations on Geant 3 and it doesn't seem to have the problem..... (In reply to comment #1) > (In reply to comment #0) > > Created an attachment (id=9) [details] [details] > > an example of wrong energy distribution of fission neutrons > > > > When using a neutron HP model, we get some fission neutrons (prompt and > > delayed) with energies around 20 MeV which doesn't seem to agree with > > experiments. The energy distribution of one example case is attached. > > > Currently, export control restrictions prevent us from making detailed > improvements to the fission models. We are in the process of making > alternative > models which perform better and avoid the above restrictions. Until they are > ready you could try the LLNL fission model. In your physics list add: > G4HadronFissionProcess *theFissionProcess = new G4HadronFissionProcess(); > G4FissLib* theFissionModel = new G4FissLib; > theFissionProcess->RegisterMe(theFissionModel); > pmanager->AddDiscreteProcess(theFissionProcess);
