fix: instead of --part.userParticleHandler='', reduce part.minimalKineticEnergy
#40
Conversation
…KineticEnergy` So far we run `npsim` with `--part.userParticleHandler=''`, which we thought we needed in order to see optical photons in the truth output. Today I learned we don't see them because the default `part.minimalKineticEnergy` is 1 MeV, too high for photons. Instead, we set this minimal energy to zero, and check if IRT reconstruction still works.
|
On second thought, after reading DDG4/plugins/Geant4TCUserParticleHandler.cpp, I don't think we should be using the default npdet_info dump $DETECTOR_PATH/$DETECTOR.xml | grep -E '^tracker_region'but the dRICH is outside of this; most likely the opticalphotons are thrown away by @wdconinc do you have any suggestions how we should be running? Should we just continue to run |
|
I have no opinion on the matter :-) As I think was clear from the tutorial :-\ I have a pretty poor grasp of what exactly causes MCParticle entries beyond the event generator input :-D As a matter of default settings in npsim, we should try to limit how much non-event generator truth we write to the MCParticles branch, both to keep the default content of MCParticles dominated by the event generator record that most people expect to find there, and to keep the size reasonable (we could easily store 1000s of MCParticles as truth, which would start to meaningfully impact our file size). I hope that's not too vague ;-) |
So far we run
npsimwith--part.userParticleHandler='', which we thought we needed in order to see optical photons in the truth output. Today I learned we don't see them because the defaultpart.minimalKineticEnergyis 1 MeV, too high for photons. Instead, we set this minimal energy to zero, and check if IRT reconstruction still works.Relevant parts from DD4hep
ParticleHandler.py