Discuss the design of IO classes

This is an issue to discuss the future design of IO classes (Event, Particles, Tracks, Photons). First we need to define current uses of these classes, and possible future uses.

I'll try to summarize all I see about these classes, please correct me if I miss or misunderstand anything.

Current usage

Event class

is the main container for all data produced in the simulation.

• created in NTSim loop
• read & modified by most of the other modules (which read&write class attributes)

Particles class

contains the info about the primary & secondary particles: starting points & energies etc.

• "Primary"

  • created in ToyGen or other PrimaryGenerators
  • appended in PrimaryPropagator with particles produced by g4
  • read by PrimaryPropagator to set initial positions in g4 simulation

• "g4_cascade_starters"

  • created by PrimaryPropagator when a particle passes certain conditions
  • read by CherenkovGenerator to create photons based on the cherenkov_cascade parameterizatrion

Tracks class

contains info about each particle trajectory step

• "g4_tracks" created by PrimaryPropagator
• "nu_tracks" created by nuGenerator/NuPropagator
• read by CherenkovGenerator to create photons based on cherenkov_tracks parameterization

Photons class

contains information about photons trajectories (each scattering step)

• "" created by SolarPhotons/Laser/IsotropicSource
• "g4_photons" created by ParticlePropagator
• "{label}_{bunch}" created by CherenkovGenerator
• read and updated by MCPhotonPropagator to propagate by a given number of scattering steps
• read by SmartRayTracer to produce hits

Hits class

contains information about each photon arriving at the sensitive detector

• produced by SmartRayTracer
• read by triggers