Introduction to GEANT4

Most of the pre-packaged physics lists use "standard" electromagnetic physics processes. The "standard" EM processes are defined with classes: G4EmStandardPhysics, G4EmStandardPhysics_option1, G4EmStandardPhysics_option2 and G4EmStandardPhysics_option3. If you want to use the "low energy" electromagnetic physics processes in the pre-packaged physics list you have to do the following:

 

 

If primary particle energy in your application is < 5 GeV (for example, clinical proton beam of 150 MeV)

start with a physics list which includes BIC or BERT

e.g. QGSP_BIC, QGSP_BERT, FTFP_BERT, etc.

 

If you’re interested in Bragg curve physics

use a physics list ending in “EMV” or “EMX”

e.g. QGSP_BERT_EMV