Guys I want to use G4 to simulate a 5mCi I-125 solution, but I have a confusion now. g4 seems to only emit particles, so I did some calculations. the activity of 5mCi is 1.85*10^8Bq, so I executed the
beamOn 1.85*10^8 command using G4, but the results don’t seem to be right. I would like to ask you all how this should be simulated.