simcore::TrigScintSD Class Reference

Class defining a sensitive detector of type trigger scintillator. More...

#include <TrigScintSD.h>

Public Member Functions
	TrigScintSD (const std::string &name, simcore::ConditionsInterface &ci, const framework::config::Parameters &p)
	Class constructor.
virtual	~TrigScintSD ()=default
	Destructor.
virtual bool	isSensDet (G4LogicalVolume *vol) const override
	Should the input logical volume be included in this sensitive detector?
G4bool	ProcessHits (G4Step *step, G4TouchableHistory *history) override
	Process steps to create hits_.
virtual void	saveHits (framework::Event &event) override
	Save our hits collection into the event bus and reset it.
virtual void	onFinishedEvent () override
	Cleanup SD and prepare a new-event state.
Public Member Functions inherited from simcore::SensitiveDetector
	SensitiveDetector (const std::string &name, simcore::ConditionsInterface &ci, const framework::config::Parameters &parameters)
	Constructor.
	DECLARE_FACTORY_WITH_WAREHOUSE (SensitiveDetector, SensitiveDetector *, const std::string &, simcore::ConditionsInterface &, const framework::config::Parameters &)
	The SD Factory.
virtual	~SensitiveDetector ()=default
	Destructor.
virtual void	EndOfEvent (G4HCofThisEvent *) override
	This is Geant4's handle to tell us the event is ending.

Private Attributes
std::vector< ldmx::SimCalorimeterHit >	hits_
	our collection of hits in this SD
std::string	collection_name_
	name of the hit collection for this SD
std::string	vol_name_
	name of trigger pad volume this SD is capturing
int	module_id_
	the ID number for the module we are gathering hits from
bool	use_birks_law_
	Whether to use Birks law for energy deposition.
double	birks_const_one_
	Birks law constants c1.
double	birks_const_two_
	Birks law constants c2.

Additional Inherited Members
Protected Member Functions inherited from simcore::SensitiveDetector
template<class T >
const T &	getCondition (const std::string &condition_name)
	Record the configuration of this detector into the run header.
bool	isGeantino (const G4Step *step) const
	Check if the passed step is a step of a geantino.
const TrackMap &	getTrackMap () const
	Get a handle to the current track map.
	enableLogging ("SensitiveDetector")
	Enable logging for this class.

Detailed Description

Class defining a sensitive detector of type trigger scintillator.

Definition at line 12 of file TrigScintSD.h.

Constructor & Destructor Documentation

TrigScintSD()

simcore::TrigScintSD::TrigScintSD	(	const std::string &	name,
		simcore::ConditionsInterface &	ci,
		const framework::config::Parameters &	p )

Class constructor.

Parameters

[in]	name	The name of the sensitive detector.
[in]	ci	interface to conditions objects
[in]	p	python configuration parameters

Definition at line 16 of file TrigScintSD.cxx.

    : SensitiveDetector(name, ci, p) {
  module_id_ = p.get<int>("module_id");
  collection_name_ = p.get<std::string>("collection_name");
  vol_name_ = p.get<std::string>("volume_name");
  use_birks_law_ = p.get<bool>("use_birks_law");
  birks_const_one_ = p.get<double>("birks_const_one");
  birks_const_two_ = p.get<double>("birks_const_two");
}

References birks_const_one_, birks_const_two_, collection_name_, framework::config::Parameters::get(), module_id_, use_birks_law_, and vol_name_.

Member Function Documentation

isSensDet()

virtual bool simcore::TrigScintSD::isSensDet ( G4LogicalVolume * vol ) const

inlineoverridevirtual

Should the input logical volume be included in this sensitive detector?

Note

Depends on names in GDML!

In order to avoid attaching to both 'target' and 'sp_target', we intentionally exclude volumes with the string 'sp_' in their names.

Implements simcore::SensitiveDetector.

Definition at line 37 of file TrigScintSD.h.

                                                              {
    return vol->GetName().contains(vol_name_) and
           not vol->GetName().contains("sp_");
  }

References vol_name_.

onFinishedEvent()

virtual void simcore::TrigScintSD::onFinishedEvent ( )

inlineoverridevirtual

Cleanup SD and prepare a new-event state.

Implements simcore::SensitiveDetector.

Definition at line 57 of file TrigScintSD.h.

{ hits_.clear(); }

References hits_.

ProcessHits()

G4bool simcore::TrigScintSD::ProcessHits ( G4Step * step, G4TouchableHistory * history )

overridevirtual

Process steps to create hits_.

Parameters

[in]	step	The step information.
[in]	history	The readout history.

Implements simcore::SensitiveDetector.

Definition at line 28 of file TrigScintSD.cxx.

                                                                         {
  // Get the energy deposited by the particle during the step
  auto energy{step->GetTotalEnergyDeposit()};
 
  // If a non-Geantino particle doesn't deposit energy during the step,
  // skip processing it.
  if (energy == 0 and not isGeantino(step)) {
    ldmx_log(trace) << "No energy deposited in step, skipping.";
    return false;
  }
 
  // Create a new instance of a calorimeter hit
  //  emplace_back returns a *reference* to the hit that was constructed
  //  and we should keep that reference so that we are editing the correct hit
  ldmx::SimCalorimeterHit& hit = hits_.emplace_back();
 
  G4StepPoint* pre_point = step->GetPreStepPoint();
  G4StepPoint* post_point = step->GetPostStepPoint();
  if (pre_point == nullptr || post_point == nullptr) {
    return false;
  }
 
  // A Geant4 "touchable" is a way to uniquely identify a particular volume,
  // short for touchable detector element. See the detector definition and
  // response section of the Geant4 application developers manual for details.
  //
  // The TouchableHandle is just a reference counted pointer to a
  // G4TouchableHistory object, which is a concrete implementation of a
  // G4Touchable interface.
  if (!pre_point->GetTouchableHandle()) {
    return false;
  }
  auto touchable_history{pre_point->GetTouchableHandle()->GetHistory()};
  // Affine transform for converting between local and global coordinates
  auto top_transform{touchable_history->GetTopTransform()};
  // Set the hit position
  auto position{0.5 * (pre_point->GetPosition() + post_point->GetPosition())};
 
  // Convert the center of the bar to its corresponding global position
  auto volume_position{top_transform.Inverse().TransformPoint(G4ThreeVector())};
  hit.setPosition(position[0], position[1], volume_position.z());
 
  // Get the track associated with this step
  auto track{step->GetTrack()};
 
  // Set the ID on the hit.
  auto bar{track->GetVolume()->GetCopyNo()};
  ldmx::TrigScintID id(module_id_, bar);
  hit.setID(id.raw());
 
  // Implement Birks law
  G4double birks_factor(1.0);
  G4double step_length = step->GetStepLength() / CLHEP::cm;
  // Do not apply Birks for gamma deposits!
  // Check, cut if necessary.
  if (step_length > 1.0e-6) {
    G4double rho = step->GetPreStepPoint()->GetMaterial()->GetDensity() /
                   (CLHEP::g / CLHEP::cm3);
    G4double dedx = energy / (rho * step_length);  //[MeV*cm^2/g]
    birks_factor =
        1.0 / (1.0 + birks_const_one_ * dedx + birks_const_two_ * dedx * dedx);
    // Birks law is only applied to charged particles
    if (step->GetTrack()->GetDefinition()->GetPDGCharge() == 0) {
      birks_factor = 1.0;
    }
  }
 
  // update the energy to include birks_factor
  if (use_birks_law_) {
    ldmx_log(trace) << "Applying Birks law with factor: " << birks_factor;
    energy *= birks_factor;
  }
 
  // add single contrib to this calorimeter hit
  //  IncidentID - this track's ID
  //  Track ID
  //  PDG ID
  //  energy deposited
  //  global time of this hit
  hit.addContrib(track->GetTrackID(), track->GetTrackID(),
                 track->GetParticleDefinition()->GetPDGEncoding(), energy,
                 track->GetGlobalTime());
 
  // Step details
  hit.setPathLength(step->GetStepLength());
  hit.setVelocity(track->GetVelocity());
  // Convert pre/post step position from global coordinates to coordinates
  // within the scintillator bar
  const auto local_pre_step_point{
      top_transform.TransformPoint(pre_point->GetPosition())};
  const auto local_post_step_point{
      top_transform.TransformPoint(post_point->GetPosition())};
  hit.setPreStepPosition(local_pre_step_point[0], local_pre_step_point[1],
                         local_pre_step_point[2]);
 
  hit.setPostStepPosition(local_post_step_point[0], local_post_step_point[1],
                          local_post_step_point[2]);
 
  hit.setPreStepTime(pre_point->GetGlobalTime());
  hit.setPostStepTime(post_point->GetGlobalTime());
 
  return true;
}

References ldmx::SimCalorimeterHit::addContrib(), birks_const_one_, birks_const_two_, hits_, simcore::SensitiveDetector::isGeantino(), module_id_, ldmx::SimCalorimeterHit::setID(), ldmx::SimCalorimeterHit::setPathLength(), ldmx::SimCalorimeterHit::setPosition(), ldmx::SimCalorimeterHit::setPostStepPosition(), ldmx::SimCalorimeterHit::setPostStepTime(), ldmx::SimCalorimeterHit::setPreStepPosition(), ldmx::SimCalorimeterHit::setPreStepTime(), ldmx::SimCalorimeterHit::setVelocity(), and use_birks_law_.

saveHits()

virtual void simcore::TrigScintSD::saveHits ( framework::Event & event )

inlineoverridevirtual

Save our hits collection into the event bus and reset it.

Implements simcore::SensitiveDetector.

Definition at line 53 of file TrigScintSD.h.

                                                        {
    event.add(collection_name_, hits_);
  }

References collection_name_, and hits_.

Member Data Documentation

birks_const_one_

double simcore::TrigScintSD::birks_const_one_

private

Birks law constants c1.

Definition at line 71 of file TrigScintSD.h.

Referenced by ProcessHits(), and TrigScintSD().

birks_const_two_

double simcore::TrigScintSD::birks_const_two_

private

Birks law constants c2.

Definition at line 73 of file TrigScintSD.h.

Referenced by ProcessHits(), and TrigScintSD().

collection_name_

std::string simcore::TrigScintSD::collection_name_

private

name of the hit collection for this SD

Definition at line 63 of file TrigScintSD.h.

Referenced by saveHits(), and TrigScintSD().

hits_

std::vector<ldmx::SimCalorimeterHit> simcore::TrigScintSD::hits_

private

our collection of hits in this SD

Definition at line 61 of file TrigScintSD.h.

Referenced by onFinishedEvent(), ProcessHits(), and saveHits().

module_id_

int simcore::TrigScintSD::module_id_

private

the ID number for the module we are gathering hits from

Definition at line 67 of file TrigScintSD.h.

Referenced by ProcessHits(), and TrigScintSD().

use_birks_law_

bool simcore::TrigScintSD::use_birks_law_

private

Whether to use Birks law for energy deposition.

Definition at line 69 of file TrigScintSD.h.

Referenced by ProcessHits(), and TrigScintSD().

vol_name_

std::string simcore::TrigScintSD::vol_name_

private

name of trigger pad volume this SD is capturing

Definition at line 65 of file TrigScintSD.h.

Referenced by isSensDet(), and TrigScintSD().

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

• SimCore/include/SimCore/SDs/TrigScintSD.h
• SimCore/src/SimCore/SDs/TrigScintSD.cxx