I’m implementing an HPGe detector in Geant4. I’ve already built the detector geometry and generated the energy spectrum. To simulate the detector’s performance, is it appropriate to apply the energy resolution (FWHM) in post-processing like this?
Yes, that’s correct. The standard form for the energy resolution σ of a detector is usually:
sigma(E)= sqrt( a + b*E )
where:
a accounts for electronic noise, typically only relevant at low energies and often negligible at higher energies
bE reflects the statistical fluctuations in the number of charge carriers (electron-hole pairs), which grow with energy. This term dominates at medium to high energies
The parameters a and b are typically extracted by fitting to measured resolution data at known gamma-ray energies.
Thank you very much for your kind and detailed explanation. Thanks to your guidance, I now have a clear understanding of the energy resolution concept and how to record the total event energy into H1. I will apply your suggestions to my code. Thank you once again!