Retrieve decay chain

Dear everyone,
I’m trying to obtaind a decay chain in a simulation experiment which as follows:
I have an electron beam with energy up to 90 MeV and gold foil (1 mm thickness). In time of simulation Au196 isotope is produced: g + Au197 = Au196 + n. What is the best way to retrieve the energy of gamma particle rigth before when it hit out the neunron from Au197?

Thak you in advance!


User stepping action user class allows making this and many other analysis. See, for example, $G4INSTALL/examples/extended/hadronic/Hadr01