How to choose the right Compton effect in a radioactive experiment

I recently intended to measure the dosimetric parameters of a radioactive source I designed, I created my own physics list and I had some problems in choosing the Compton effect. I found a lot of Compton effect classes in the G4 manual.

In particular, I read in the manual: low-energy sub-library there are alternative models. Here I see a lot of Compton effect classes, such as G4PenelopeComptonModel, G4LivermoreComptonModel, G4LivermorePolarizedComptonModel, G4LowEPComptonModel, G4LowEPPolarizedComptonModel.

But I really don’t know which one I should choose. Please tell me which Compton effect I should choose in conducting low-energy radioactive experiments.

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Hi Jodie,

it depends on what’s the energy range of your interest, what the precision that you need and how much CPU time you are willing to spend. If you are interested in 100’s of keV gamma-rays, the best compromise is probably to use Livermore or Penelope, as they account for atomic effects (e.g. Doppler broadening in the Compton edge and fluorescence from the atomic vacancies). I assume you don’t care about polarization, as you work with radioactive sources.

Have a good day,

Thank you for your reply this is very helpful to me

Jodie, I would suggest first to use a pre-built Geant4 EM constructor (either Livermore or Penelope as recommended by Luciano), rather than building the physics list from scratch.


ok Susanna I will try your suggestion and thank you for your reply.