GEMSignalModel Class Reference

#include <GEMSignalModel.h>

Inheritance diagram for GEMSignalModel:

Public Member Functions
	GEMSignalModel (const edm::ParameterSet &)
int	getSimHitBx (const PSimHit *, CLHEP::HepRandomEngine *)
void	simulate (const GEMEtaPartition *, const edm::PSimHitContainer &, CLHEP::HepRandomEngine *, Strips &, DetectorHitMap &) override
std::vector< std::pair< int, int > >	simulateClustering (const GEMStripTopology *, const PSimHit *, const int, CLHEP::HepRandomEngine *)
	~GEMSignalModel () override
Public Member Functions inherited from GEMDigiModel
void	setGeometry (const GEMGeometry *geom)
virtual	~GEMDigiModel ()

Private Attributes
double	averageEfficiency_
double	averageShapingTime_
bool	bx0filter_
const double	cspeed
bool	digitizeOnlyMuons_
const double	energyMinCut
double	resolutionX_
double	signalPropagationSpeed_
double	timeJitter_
double	timeResolution_

Additional Inherited Members
Protected Member Functions inherited from GEMDigiModel
	GEMDigiModel (const edm::ParameterSet &)
Protected Attributes inherited from GEMDigiModel
const GEMGeometry *	geometry_

Detailed Description

Class for the GEM strip intrinsic noise simulation based on a very simple model Originally comes from GEMSimpleModel

Author

Sven Dildick by Roumyana Hadjiiska by Yechan Kang

Class for the GEM strip response simulation based on a very simple model Originally comes from GEMSimpleModel

Author

Sven Dildick by Roumyana Hadjiiska by Yechan Kang

Definition at line 24 of file GEMSignalModel.h.

Constructor & Destructor Documentation

GEMSignalModel()

GEMSignalModel::GEMSignalModel

(

const edm::ParameterSet &

config

)

Definition at line 16 of file GEMSignalModel.cc.

    : GEMDigiModel(config),
      averageEfficiency_(config.getParameter<double>("averageEfficiency")),
      averageShapingTime_(config.getParameter<double>("averageShapingTime")),
      timeResolution_(config.getParameter<double>("timeResolution")),
      timeJitter_(config.getParameter<double>("timeJitter")),
      signalPropagationSpeed_(config.getParameter<double>("signalPropagationSpeed")),
      resolutionX_(config.getParameter<double>("resolutionX")),
      cspeed(geant_units::operators::convertMmToCm(CLHEP::c_light)),
      // average energy required to remove an electron due to ionization for an Ar/CO2 gas mixture (in the ratio of 70/30) is 28.1 eV
      energyMinCut(28.1e-09) {}

~GEMSignalModel()

GEMSignalModel::~GEMSignalModel ( )

override

Definition at line 28 of file GEMSignalModel.cc.

{}

Member Function Documentation

getSimHitBx()

int GEMSignalModel::getSimHitBx	(	const PSimHit *	simhit,
		CLHEP::HepRandomEngine *	engine
	)

Definition at line 48 of file GEMSignalModel.cc.

References averageShapingTime_, nano_mu_digi_cff::bx, cspeed, PSimHit::detUnitId(), GEMGeometry::etaPartition(), Exception, GEMDigiModel::geometry_, l1ctLayer2EG_cff::id, PSimHit::localPosition(), LogDebug, nano_mu_digi_cff::roll, signalPropagationSpeed_, mathSSE::sqrt(), timeJitter_, PSimHit::timeOfFlight(), timeResolution_, PV3DBase< T, PVType, FrameType >::x(), PV3DBase< T, PVType, FrameType >::y(), and PV3DBase< T, PVType, FrameType >::z().

Referenced by simulate().

                                                                                   {
  int bx = -999;
  const LocalPoint simHitPos(simhit->localPosition());
  const float tof(simhit->timeOfFlight());
  // random Gaussian time correction due to electronics jitter
  float randomJitterTime = CLHEP::RandGaussQ::shoot(engine, 0., timeJitter_);
  const GEMDetId id(simhit->detUnitId());
  const GEMEtaPartition* roll(geometry_->etaPartition(id));
  if (!roll) {
    throw cms::Exception("Geometry") << "GEMSignalModel::getSimHitBx() - GEM simhit id does not match any GEM roll id: "
                                     << id << "\n";
    return 999;
  }
  if (roll->id().region() == 0) {
    throw cms::Exception("Geometry")
        << "GEMSignalModel::getSimHitBx() - this GEM id is from barrel, which cannot happen: " << roll->id() << "\n";
  }
  const int nstrips = roll->nstrips();
  float middleStrip = nstrips / 2.;
  const LocalPoint& middleOfRoll = roll->centreOfStrip(middleStrip);
  const GlobalPoint& globMiddleRol = roll->toGlobal(middleOfRoll);
  double muRadius = sqrt(globMiddleRol.x() * globMiddleRol.x() + globMiddleRol.y() * globMiddleRol.y() +
                         globMiddleRol.z() * globMiddleRol.z());
  double timeCalibrationOffset_ = muRadius / cspeed;  //[ns]

  const GEMStripTopology* top(dynamic_cast<const GEMStripTopology*>(&(roll->topology())));
  const float halfStripLength(0.5 * top->stripLength());
  const float distanceFromEdge(halfStripLength - simHitPos.y());

  // signal propagation speed in material in [cm/ns]
  double signalPropagationSpeedTrue = signalPropagationSpeed_ * cspeed;

  // average time for the signal to propagate from the SimHit to the top of a strip
  const float averagePropagationTime(distanceFromEdge / signalPropagationSpeedTrue);
  // random Gaussian time correction due to the finite timing resolution of the detector
  float randomResolutionTime = CLHEP::RandGaussQ::shoot(engine, 0., timeResolution_);
  const float simhitTime(tof + averageShapingTime_ + randomResolutionTime + averagePropagationTime + randomJitterTime);
  float referenceTime = 0.;
  referenceTime = timeCalibrationOffset_ + halfStripLength / signalPropagationSpeedTrue + averageShapingTime_;
  const float timeDifference(simhitTime - referenceTime);
  // assign the bunch crossing
  bx = static_cast<int>(std::round((timeDifference) / 25.));

  // check time
  LogDebug("GEMDigiProducer") << "checktime "
                              << "bx = " << bx << "\tdeltaT = " << timeDifference << "\tsimT =  " << simhitTime
                              << "\trefT =  " << referenceTime << "\ttof = " << tof
                              << "\tavePropT =  " << averagePropagationTime
                              << "\taveRefPropT = " << halfStripLength / signalPropagationSpeedTrue << "\n";
  return bx;
}

simulate()

void GEMSignalModel::simulate ( const GEMEtaPartition *  roll, const edm::PSimHitContainer &  simHits, CLHEP::HepRandomEngine *  engine, Strips &  strips_, DetectorHitMap &  detectorHitMap_  )

overridevirtual

Implements GEMDigiModel.

Definition at line 30 of file GEMSignalModel.cc.

References nano_mu_digi_cff::bx, energyMinCut, getSimHitBx(), nano_mu_digi_cff::roll, FastTrackerRecHitCombiner_cfi::simHits, and simulateClustering().

                                                               {
  const GEMStripTopology* top(dynamic_cast<const GEMStripTopology*>(&(roll->topology())));
  for (const auto& hit : simHits) {
    if (hit.energyLoss() < energyMinCut)
      continue;
    const int bx(getSimHitBx(&hit, engine));
    const std::vector<std::pair<int, int> >& cluster(simulateClustering(top, &hit, bx, engine));
    for (const auto& digi : cluster) {
      detectorHitMap_.emplace(digi, &hit);
      strips_.emplace(digi);
    }
  }
}

simulateClustering()

std::vector< std::pair< int, int > > GEMSignalModel::simulateClustering	(	const GEMStripTopology *	top,
		const PSimHit *	simHit,
		const int	bx,
		CLHEP::HepRandomEngine *	engine
	)

Definition at line 100 of file GEMSignalModel.cc.

References funct::abs(), nano_mu_digi_cff::bx, GEMStripTopology::channel(), resolutionX_, rpcPointValidation_cfi::simHit, nano_mu_digi_cff::strip, and PV3DBase< T, PVType, FrameType >::x().

Referenced by simulate().

                                                                                                   {
  const LocalPoint& hit_entry(simHit->entryPoint());
  const LocalPoint& hit_exit(simHit->exitPoint());

  LocalPoint start_point, end_point;
  if (hit_entry.x() < hit_exit.x()) {
    start_point = hit_entry;
    end_point = hit_exit;
  } else {
    start_point = hit_exit;
    end_point = hit_entry;
  }

  // Add Gaussian noise to the points towards outside.
  float smeared_start_x = start_point.x() - std::abs(CLHEP::RandGaussQ::shoot(engine, 0, resolutionX_));
  float smeared_end_x = end_point.x() + std::abs(CLHEP::RandGaussQ::shoot(engine, 0, resolutionX_));

  LocalPoint smeared_start_point(smeared_start_x, start_point.y(), start_point.z());
  LocalPoint smeared_end_point(smeared_end_x, end_point.y(), end_point.z());

  int cluster_start = top->channel(smeared_start_point);
  int cluster_end = top->channel(smeared_end_point);

  std::vector<std::pair<int, int> > cluster;
  for (int strip = cluster_start; strip <= cluster_end; strip++) {
    cluster.emplace_back(strip, bx);
  }

  return cluster;
}

Member Data Documentation

averageEfficiency_

double GEMSignalModel::averageEfficiency_

private

Definition at line 41 of file GEMSignalModel.h.

averageShapingTime_

double GEMSignalModel::averageShapingTime_

private

Definition at line 42 of file GEMSignalModel.h.

Referenced by getSimHitBx().

bx0filter_

bool GEMSignalModel::bx0filter_

private

Definition at line 46 of file GEMSignalModel.h.

cspeed

const double GEMSignalModel::cspeed

private

Definition at line 50 of file GEMSignalModel.h.

Referenced by getSimHitBx().

digitizeOnlyMuons_

bool GEMSignalModel::digitizeOnlyMuons_

private

Definition at line 47 of file GEMSignalModel.h.

energyMinCut

const double GEMSignalModel::energyMinCut

private

Definition at line 51 of file GEMSignalModel.h.

Referenced by simulate().

resolutionX_

double GEMSignalModel::resolutionX_

private

Definition at line 48 of file GEMSignalModel.h.

Referenced by simulateClustering().

signalPropagationSpeed_

double GEMSignalModel::signalPropagationSpeed_

private

Definition at line 45 of file GEMSignalModel.h.

Referenced by getSimHitBx().

timeJitter_

double GEMSignalModel::timeJitter_

private

Definition at line 44 of file GEMSignalModel.h.

Referenced by getSimHitBx().

timeResolution_

double GEMSignalModel::timeResolution_

private

Definition at line 43 of file GEMSignalModel.h.

Referenced by getSimHitBx().