How do production cuts (in range) work in Geant4 ? Are they also used in tracking ? If a particle has an energy lower than the converted cut in energy for the given material and the distance to the next boundary is smaller than the cut in range, is the particle killed ?
Geant4 does NOT have a "tracking cut". The toolkit's default behaviour is to track particles down to zero range (i.e. zero energy). Of course, it is possible for the user to create and register a process that kills particles below a certain energy or range; this is however NOT provided by default in Geant4. So there's NO "tracking cut". For example, suppose a particle that is nearing zero energy will at some point be proposed by its Ionisation process to undergo one final step, from its current energy down to zero energy. This is still only a proposal. If during this step the particle crosses a boundary, then the transportation will limit the step at a length smaller than the Ionisation -- so the particle will still see and cross the relevant boundary, and another step will occur on the other side of that boundary. In summary the "production threshold" range and its equivalent in energy are not utilised as a "tracking cut". A particle is not abandoned by Geant4 below a certain range/energy unless the user registers a process to do this by him/her-self.