HEP and Geant

The HEP libraries turn detector measurements and simulated tracks into reconstruction inputs and images. Their normal link order is:

mutomCore + mutomMath
        └── mutomDetectors
              ├── mutomMuonTomography
              └── mutomGeant

The classes are in uLib. Geant integration classes are in uLib::Geant and require the Geant4-enabled mutomGeant target.

Detectors: measurements and scatter events

DetectorChamber is a placeable ContainerBox that models a tracking chamber. It defines its measuring plane, finite/infinite footprint, position and angular resolutions, and efficiency. It produces the measurements from which a MuonEvent and then a MuonScatter are reconstructed.

#include <Core/ObjectsContext.h>
#include <HEP/Detectors/DetectorChamber.h>

uLib::ObjectsContext context;
auto *upper = context.CreateObject<uLib::DetectorChamber>("upper");
auto *lower = context.CreateObject<uLib::DetectorChamber>("lower");

upper->Position.Set({0.0f, 500.0f, 0.0f});
lower->Position.Set({0.0f, -500.0f, 0.0f});
upper->PositionResolution.Set(1.0);
lower->PositionResolution.Set(1.0);

The detector data families are:

Family	Public types	Role
Hits	HitData, HitRawCode_CMSDrift, HitMCData, HitMC	Raw and Monte Carlo detector hits.
Event values	ChamberHitEventData, ChamberHitEvent, MuonEventData, MuonEvent, ExperimentFitEventData, LinearFitData, LinearFit, MuonErrorData, MuonError	Measurements, fitted tracks, and uncertainties.
Scattering	MuonScatter, MuonScatterEvent, MuonScatterCollection	Reconstructed incoming/outgoing track pair and collections of events.
Streaming adapter	IMuonScatterSink, MuonScatterSource	Sink and bounded, waitable producer for live scatter events.

MuonScatterSource is especially useful for long simulations. It implements a bounded stream: a producer calls BeginMuonStream, AcceptMuonScatter, and EndMuonStream; a reconstruction reads it as a Core stream. Its Capacity, BatchSize, NotifyEvery, and WaitTimeout properties state the back-pressure and notification policy. See live muon reconstruction.

Muon tomography

MuonTomographyAlgorithm owns the common reconstruction loop. It can read a precomputed MuonScatterCollection through SetEvents or an IStreamProducer through SetStream, and writes an Abstract::VoxImage attached with SetImage. Its subclasses supply the reconstruction rule:

Class	Reconstruction
PocaImageAlgorithm	Point-of-closest-approach image.
RayLengthImageAlgorithm	Voxelized path/ray-length image.

#include <HEP/MuonTomography/MuonTomographyImaging.h>
#include <HEP/Detectors/MuonScatterCollection.h>
#include <Math/VoxImage.h>

uLib::MuonScatterCollection events;
uLib::VoxImage<uLib::Voxel> image{uLib::Vector3i{80, 80, 80}};
uLib::PocaImageAlgorithm reconstruction;

reconstruction.SetEvents(&events);
reconstruction.SetImage(&image);
reconstruction.Run();

For live batches, use SetStream, turn ResetImage off after the first batch, and choose whether DriveStream should request work or merely drain an already notified buffer. This distinction prevents a consumer that is running in response to a notification from recursively starting another producer.

Geant

mutomGeant bridges the editable uLib scene to Geant4. A Geant::Scene holds the simulation setup; Geant::Physics and Geant::PhysicsList configure processes; particle sources generate primaries; volumes and solids define geometry; and actions, scoring, and sensitive detectors collect results.

Build a scene declaratively

Construct the uLib objects, arrange them in an ObjectsContext, then configure/run the Geant scene through its public API. The exact Geant4 run-manager setup belongs to Geant::Scene; avoid holding raw Geant4 geometry pointers in application code, because the scene owns and rebuilds the Geant objects when its uLib objects change.

#include <Core/ObjectsContext.h>
#include <HEP/Geant/Scene.h>
#include <HEP/Geant/Solid.h>

uLib::ObjectsContext context;
auto *scene = context.CreateObject<uLib::Geant::Scene>("simulation");
scene->ConstructWorldBox(
    uLib::Vector3f{2000.0f, 2000.0f, 2000.0f}, "G4_AIR");

Geant class groups

Group	Main exported classes
Scene and run	Scene, SimulationContext, DetectorPlane, GeantEvent, GeantEventCollection, GeantFailure, ExceptionScope
Geometry	Solid, LogicalVolume, PhysicalVolume, BoxSolid, CylinderSolid, SphereSolid, ConeSolid, TessellatedSolid, Boolean solids, AssemblyVolume, replica/division/parameterised volumes, Region
Materials and fields	Isotope, Element, MaterialComponent, Material, Field, MagneticField, ElectricField, UserLimits
Primary sources	ParticleGun, IsotropicSource, EmitterPrimary, SkyPlaneEmitterPrimary, CylinderEmitterPrimary, QuadMeshEmitterPrimary, EMLog, EMRandom, EMMaximization, EMMultiGen, EcoMug
Actions and output	ActionInitialization, DetectorActionInitialization, DetectorConstruction, SteppingAction, DetectorSteppingAction, TrackRecorder, TrackRecord, RunSummary
Scoring	SensitiveDetector, Hit, ScoringDetector, Scorer, ScoringMesh, ScoringFilter, ParticleFilter, ChargeFilter, EnergyFilter
Other Geant domains	Digitizer, Digi, OpticalProperty, OpticalSurface, BorderSurface, ParallelWorld, ReflectedVolume, VoxelPhantom, PlaneProbe, ProbeStep, ProbeStepRecord, TrackFilter, TrackFacts

The complete class catalog lists each installed header and type. For a full end-to-end producer/consumer setup, continue with the C++ streaming guide.