I hope I’m in the right forum for this. I’m trying to perform computed tomography using projections made with Geant4. I’m creating materials based on NIST elements.
When running the CT algorithm using projections I got for Geant4, I’m able to recover with good accuracy attenuation coefficients (when comparing to the attenuation coefficients given in NIST tables) of elements with low z (i.e. H, C, N, O) but for elements with higher Z values (P and Ca) I’m not recovering the right values, the values I recover are about half of what I expected.
From what do you think this can arise? I’m using the FTFP_BERT_LIV physics list and use gamma particles with up to 120keV energy. Could I be using a physics list that isn’t a good fit?