Thanks for your reply, @John_McFee .
The output is generated by the command “/tracking/verbose 2”. This output is part of a neutron’s track.
The code is written by myself.
As far as I could understand, the output shows that the gammas ( with energy of 4.07 MeV, 4.7 MeV, 0.916 MeV etc.) is the secondaries of the neutron after the process “nCapture”. The sum of these gamma’s energy is obviously greater than the Q-value. This is what confuses me.
The output is part of a neutron’s track, so it is correspond to a single event.
I upload another output of a neutron’s track, which shows the process from generation to the end of life of a neutron and all the secondaries.
Gd157(n, gamma)Gd158.txt (20.7 KB)
I believe this post “Weird Features in Gamma Spectrum for Neutron Capture on Gd” has the same question as me.
Geant4 version of mine is 10.7.2 and the neutron data base is G4NDL4.6.