X-ray creation

The characteristic X-ray creation by ionizing particles in a material is demonstrated in fluorescence.mac, where 5.5 MeV alpha rays are shot to a thin Al foil defined in foil.tg.Minimal macro commands needed to create characteristic X-ray are:

# working EM options: _LIV, _PEN, _EMY, _EMZ
/physics_lists/select LBE_LIV
# /process/em/ only exists with radioactive decay being enabled
/physics_lists/factory/addRadioactiveDecay
# PIXE must be used to enable the creation of characteristic X-rays
/process/em/pixe true
# /run/initialize must be called after the physics setups above
/run/initialize

For detailed tuning, please refer to Geant4 node 1620.