celeritas::ScintillationOffload Class Reference

A replacement for Geant4's G4Scintillation process which constructs GeneratorDistributionData from a PostStepDoIt call. More...

#include <ScintillationOffload.hh>

Inheritance diagram for celeritas::ScintillationOffload:

Public Member Functions
void	PreparePhysicsTable (G4ParticleDefinition const &) override
	Prepare physics table for particle and enforce photon stacking.
G4VParticleChange *	PostStepDoIt (G4Track const &aTrack, G4Step const &aStep) override
	Create a generator distribution for the given track and step.
G4VParticleChange *	AtRestDoIt (G4Track const &aTrack, G4Step const &aStep) override
	Create a generator distribution for the given track and step.
	ScintillationOffload (ParticleTrackView const &particle, SimTrackView const &sim, Real3 const &pos, units::MevEnergy energy_deposition, NativeCRef< ScintillationData > const &shared, OffloadPreStepData const &pre_step, OffloadPrePostStepData const &pre_post_step)
	Construct with input parameters.
template<class Generator >
optical::GeneratorDistributionData	operator() (Generator &rng)
	Collect the distribution data needed to sample scintillation photons.

Detailed Description

A replacement for Geant4's G4Scintillation process which constructs GeneratorDistributionData from a PostStepDoIt call.

Sample the number of scintillation photons to be generated.

This process should have stacking photons set to false so that photons are not initialized in Geant4.

This populates the GeneratorDistributionData used by the ScintillationGenerator to generate optical photons using post-step and cached pre-step data.

The post-step speed is calculated from the particle's energy after continuous slowing down but before the particle loses energy in a discrete interaction.

The mean number of photons is a product of the energy deposition and a material-dependent yield fraction (photons per MeV). The actual number of photons sampled is determined by sampling:

• for large (n > 10) mean yield, from a Gaussian distribution with a material-dependent spread, or
• for small yields, from a Poisson distribution.

Constructor & Destructor Documentation

ScintillationOffload()

celeritas::ScintillationOffload::ScintillationOffload ( ParticleTrackView const &  particle, SimTrackView const &  sim, Real3 const &  pos, units::MevEnergy  energy_deposition, NativeCRef< ScintillationData > const &  shared, OffloadPreStepData const &  pre_step, OffloadPrePostStepData const &  pre_post_step  )

inline

Construct with input parameters.

Todo:

Use visible energy deposition when Birks law is implemented

Member Function Documentation

AtRestDoIt()

G4VParticleChange * celeritas::ScintillationOffload::AtRestDoIt ( G4Track const &  aTrack, G4Step const &  aStep  )

override

Create a generator distribution for the given track and step.

Since G4Scintillation has a qualified call to its own PostStepDoIt method, this override defers to ScintillationOffload::PostStepDoIt instead.

operator()()

template<class Generator >

optical::GeneratorDistributionData celeritas::ScintillationOffload::operator() ( Generator &  rng )

inline

Collect the distribution data needed to sample scintillation photons.

If no photons are sampled an empty object is returned.

PostStepDoIt()

G4VParticleChange * celeritas::ScintillationOffload::PostStepDoIt ( G4Track const &  aTrack, G4Step const &  aStep  )

override

Create a generator distribution for the given track and step.

Stacking photons should be disabled so that photons are not duplicated in Geant4. After calling the G4Scintillation::PostStepDoIt this function creates a GeneratorDistributionData and pushes it to the local offload, which should be LocalOpticalGenOffload.

PreparePhysicsTable()

void celeritas::ScintillationOffload::PreparePhysicsTable ( G4ParticleDefinition const &  particle )

override

Prepare physics table for particle and enforce photon stacking.

Defers physics table preparation to G4Scintillation, but also enforces that stacking photons is false afterwards.

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The documentation for this class was generated from the following files:

• accel/gen/ScintillationOffload.hh
• celeritas/optical/gen/ScintillationOffload.hh
• ScintillationOffload.cc