Determening mean ionization energy for some material

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Geant4 Version: 10
Operating System: Red Hat 9
Compiler/Version: 11.4.1
CMake Version: doesn’t matter for this question

I’m trying to simulate a CeBr3 crystal for medical imaging (gamma detection below 2MeV, preferably between 10keV through 800 keV). I’m stuck trying to define this crystal material. I’ve got the density but I can’t find what the mean ionization energy is. I’m not sure how the mean ionization energy is used when modeling electrons tracking through the crystal as they deposit their energy to form scintillation photons. I’m not actually simulating the final scintillation photons, I’m just interested in the energy deposition in the crystal and making sure the attenuation or gamma interaction efficiency is correct so that I can measure the overall efficiency of my detector to triggering on gamma’s hitting my CeBr3 crystal. Could it be that I can ignore the mean ionization energy?

Any help is welcome. thanks.


Is this a parameter you have to set? Birks coefficient? If so, it may only pertain to how much scintillation light is produced as a function of energy deposition. I would assume that the stopping power of the material for electrons would only be a function of the electron density.

Geant4 should calculate this automatically for you. If you print the materials it should show the value.