By high energy I mean 100+ MeV gamma rays. I think that at this energy of photons, pair production is the dominating absorption process.
So, as known, in pair production an electron and a positron are produced and any excess energy of the photon over the rest mass of the electron and the positron will be in the form of the kinetic energy of the new electron and positron.
So now, how will the electron and positron end up in a dense material ? like will the electron come to a stop releasing its in energy in the material and thus heating it up ? or will it escape the material ?
I am assuming using the attenuation length of Lead at this gamma ray energy as the absorbing material.