Code that uses the Geant4 toolkit to simulate photon emission and pair creation from relativistic electron beams passing through metal targets.
Assuming Geant4 has already been installed:
cd build
cmake ..
make./dreamt materal thickness energy [number]
will run dreamt for a target made of material (e.g. G4_Pb for elemental lead) that is thickness (in microns) in depth. The energy of the primary electron beam is specified in MeV. The number of primaries is optional: the default is 1e8.