I am building an application in which I have a World volume filled with water and a BGO scintillation crystal in the very center of the World. From the center of the World (and thus the center of the BGO) I launch 4.4 MeV gamma-rays which will produce big amount of scintillation light and then Cherenkov light once it reaches the water.
I have my analysis set to record all the information about primary and secondary particles in the BGO and the World volumes, but there is one thing I find very interesting but do not know how to achieve: I would like to know the energy of the gamma when it passes from the BGO to the World, its energy just after the BGO frontier.
I would be very grateful if someone could help me do this.
Thanks in advance, Diego