Created attachment 738 [details] Evaporation spectra for neutrons, protons and alpha-particles Proton and alpha particles spectra possess a long "tail" of the distribution that is not typical for an evaporation spectra, see an attachment. Default method for kinetic energy sampling in G4Evaporation is an inherited method from G4VEmissionProbability G4VEmissionProbability::SampleEnergy() (red histogram in the attached picture), probably some bugs can be there. For the details see: https://geant4-forum.web.cern.ch/t/strange-distribution-of-kinetic-energy-of-evaporated-fragments-in-g4evaporation/6505
Hello Aleksandr, thank you for this report. We need to improve our evaporation code. However, we cannot do anything about Geant4 10.4. With the current manpower and LHC schedule we can introduce improvements to Geant4 11.0 and/or back-port fixes to Geant4 10.7. Geant4 has no possibility to make official patches even to Geant4 10.6. After 10.4 there were several updates of the code, so it is difficult make assumptions what to change or improve. If you strongly coupled with Geant4 10.4 I would think about possibility to back-port de-excitation directory from 11.0 to 10.4. In that case we can improve de-excitation. VI
Hello Aleksandr, the problem is fixed and the fix will be available with the next public release in December 2022. The problem was in low limit on number of attempts to sample energy of the emitted fragment. The limit is increased and more smart regression method is used. Vladimir
