_Geant4 Version:_11.1
_Operating System:_VScode
I rewrote B4a to simulate neutron bombardment of polyethylene to obtain recoil protons。I have a question that When I am using a 1MeV neutron source to draw an image, I cannot obtain a 1MeV recoil proton and can only obtain 0.96MeV,（ 4MeV，obtain 3.96MeV）
I need help.