ecal::EcalRecProducer Class Reference

Performs basic ECal reconstruction. More...

#include <EcalRecProducer.h>

Public Member Functions
	EcalRecProducer (const std::string &name, framework::Process &process)
	Constructor.
virtual	~EcalRecProducer ()
	Destructor.
virtual void	configure (framework::config::Parameters &)
	Grabs configure parameters from the python config file.
virtual void	produce (framework::Event &event)
	Produce EcalHits and put them into the event bus using the EcalDigis as input.
Public Member Functions inherited from framework::Producer
	Producer (const std::string &name, Process &process)
	Class constructor.
virtual void	beforeNewRun (ldmx::RunHeader &header)
	Handle allowing producers to modify run headers before the run begins.
Public Member Functions inherited from framework::EventProcessor
	EventProcessor (const std::string &name, Process &process)
	Class constructor.
virtual	~EventProcessor ()
	Class destructor.
virtual void	onNewRun (const ldmx::RunHeader &runHeader)
	Callback for the EventProcessor to take any necessary action when the run being processed changes.
virtual void	onFileOpen (EventFile &eventFile)
	Callback for the EventProcessor to take any necessary action when a new event input ROOT file is opened.
virtual void	onFileClose (EventFile &eventFile)
	Callback for the EventProcessor to take any necessary action when a event input ROOT file is closed.
virtual void	onProcessStart ()
	Callback for the EventProcessor to take any necessary action when the processing of events starts, such as creating histograms.
virtual void	onProcessEnd ()
	Callback for the EventProcessor to take any necessary action when the processing of events finishes, such as calculating job-summary quantities.
template<class T >
const T &	getCondition (const std::string &condition_name)
	Access a conditions object for the current event.
TDirectory *	getHistoDirectory ()
	Access/create a directory in the histogram file for this event processor to create histograms and analysis tuples.
void	setStorageHint (framework::StorageControl::Hint hint)
	Mark the current event as having the given storage control hint from this module.
void	setStorageHint (framework::StorageControl::Hint hint, const std::string &purposeString)
	Mark the current event as having the given storage control hint from this module and the given purpose string.
int	getLogFrequency () const
	Get the current logging frequency from the process.
int	getRunNumber () const
	Get the run number from the process.
std::string	getName () const
	Get the processor name.
void	createHistograms (const std::vector< framework::config::Parameters > &histos)
	Internal function which is used to create histograms passed from the python configuration @parma histos vector of Parameters that configure histograms to create.

Private Attributes
std::string	digiCollName_
	Digi Collection Name to use as input.
std::string	digiPassName_
	Digi Pass Name to use as input.
std::string	simHitCollName_
	simhit collection name
std::string	simHitPassName_
	simhit pass name
std::string	recHitCollName_
	output hit collection name
double	mip_si_energy_
	Energy [MeV] deposited by a MIP in Si 0.5mm thick.
double	clock_cycle_
	Length of clock cycle [ns].
double	charge_per_mip_
	Number of electrons generated by average MIP in Si 0.5mm thick.
std::vector< double >	layerWeights_
	Layer Weights to use for this reconstruction.
double	secondOrderEnergyCorrection_
	Second Order Energy Correction to use for this reconstruction.

Additional Inherited Members
Static Public Member Functions inherited from framework::EventProcessor
static void	declare (const std::string &classname, int classtype, EventProcessorMaker *)
	Internal function which is part of the PluginFactory machinery.
Static Public Attributes inherited from framework::Producer
static const int	CLASSTYPE {1}
	Constant used to track EventProcessor types by the PluginFactory.
Protected Member Functions inherited from framework::EventProcessor
void	abortEvent ()
	Abort the event immediately.
Protected Attributes inherited from framework::EventProcessor
HistogramHelper	histograms_
	Interface class for making and filling histograms.
NtupleManager &	ntuple_ {NtupleManager::getInstance()}
	Manager for any ntuples.
logging::logger	theLog_
	The logger for this EventProcessor.

Detailed Description

Performs basic ECal reconstruction.

Reconstruction is done from the EcalDigi samples. Some hard-coded parameters are used for position and energy calculation.

Definition at line 33 of file EcalRecProducer.h.

Constructor & Destructor Documentation

EcalRecProducer()

ecal::EcalRecProducer::EcalRecProducer	(	const std::string &	name,
		framework::Process &	process
	)

Constructor.

Definition at line 17 of file EcalRecProducer.cxx.

    : Producer(name, process) {}

~EcalRecProducer()

ecal::EcalRecProducer::~EcalRecProducer ( )

virtual

Destructor.

Definition at line 21 of file EcalRecProducer.cxx.

{}

Member Function Documentation

configure()

void ecal::EcalRecProducer::configure ( framework::config::Parameters &  ps )

virtual

Grabs configure parameters from the python config file.

Reimplemented from framework::EventProcessor.

Definition at line 23 of file EcalRecProducer.cxx.

                                                             {
  // collection names
  digiCollName_ = ps.getParameter<std::string>("digiCollName");
  digiPassName_ = ps.getParameter<std::string>("digiPassName");
  simHitCollName_ = ps.getParameter<std::string>("simHitCollName");
  simHitPassName_ = ps.getParameter<std::string>("simHitPassName");
  recHitCollName_ = ps.getParameter<std::string>("recHitCollName");
 
  layerWeights_ = ps.getParameter<std::vector<double>>("layerWeights");
  secondOrderEnergyCorrection_ =
      ps.getParameter<double>("secondOrderEnergyCorrection");
 
  mip_si_energy_ = ps.getParameter<double>("mip_si_energy");
  clock_cycle_ = ps.getParameter<double>("clock_cycle");
  charge_per_mip_ = ps.getParameter<double>("charge_per_mip");
}

References charge_per_mip_, clock_cycle_, digiCollName_, digiPassName_, framework::config::Parameters::getParameter(), layerWeights_, mip_si_energy_, recHitCollName_, secondOrderEnergyCorrection_, simHitCollName_, and simHitPassName_.

produce()

void ecal::EcalRecProducer::produce ( framework::Event &  event )

virtual

Produce EcalHits and put them into the event bus using the EcalDigis as input.

This function unfolds the digi samples taken by the HGC ROC and reconstructs their energy using knowledge of how the chip operates and the position using EcalGeometry.

Negative Electron (charge) count This reconstruction error occurs when the ADC value is below the ADC pedestal for that channel. In the normal running mode, this will never happen because our front-end (the digi emulator or the digitizer itself) will suppress any signals that are below the readout threshold. Nevertheless, in some running modes, we don't have this zero suppression, so we need to check that the reconstruction charge (count of electrons) is non-negative.

Implements framework::Producer.

Definition at line 40 of file EcalRecProducer.cxx.

                                                   {
  // Get the Ecal Geometry
  const auto& geometry = getCondition<ldmx::EcalGeometry>(
      ldmx::EcalGeometry::CONDITIONS_OBJECT_NAME);
 
  // Get the reconstruction parameters
  EcalReconConditions the_conditions(
      getCondition<conditions::DoubleTableCondition>(
          EcalReconConditions::CONDITIONS_NAME));
 
  std::vector<ldmx::EcalHit> ecalRecHits;
  auto ecalDigis =
      event.getObject<ldmx::HgcrocDigiCollection>(digiCollName_, digiPassName_);
  // loop through digis
  for (auto digi : ecalDigis) {
    // ID from first digi sample
    //  assuming rest of samples have same ID
    ldmx::EcalID id(digi.id());
 
    // ID to real space position
    auto [x, y, z] = geometry.getPosition(id);
 
    // TOA is the time of arrival with respect to the 25ns clock window
    //  TODO what to do if hit NOT in first clock cycle?
    double timeRelClock25 = digi.soi().toa() * (clock_cycle_ / 1024);  // ns
    double hitTime = timeRelClock25;
 
    // get the estimated charge deposited from digi samples
    double charge(0.);
 
    /* debug printout
    std::cout << "Recon { "
        << "ID: " << id << ", "
        << "TOA: " << hitTime << "ns } ";
        */
    if (digi.isTOT()) {
      // TOT - number of clock ticks that pulse was over threshold
      //  this is related to the amplitude of the pulse approximately through a
      //  linear drain rate the amplitude of the pulse is related to the energy
      //  deposited
 
      // convert the time over threshold into a total energy deposited in the
      // silicon
      //  (time over threshold [ns] - pedestal) * gain
      charge = (digi.tot() - the_conditions.totPedestal(id)) *
               the_conditions.totGain(id);
 
      /* debug printout
      std::cout << "TOT Mode -> " << digi.tot() << "TDC -> " << charge << " fC";
       */
    } else {
      // ADC mode of readout
      // ADC - voltage measurement at a specific time of the pulse
      // Pulse Shape:
      //  p[0]/(1.0+exp(p[1](t-p[2]+p[3]-p[4])))/(1.0+exp(p[5]*(t-p[6]+p[3]-p[4])))
      //  p[0] = amplitude to be fit (TBD)
      //  p[1] = -0.345 shape parameter - rate of up slope
      //  p[2] = 70.6547 shape parameter - time of up slope relative to shape
      //  fit p[3] = 77.732 shape parameter - time of peak relative to shape fit
      //  p[4] = peak time to be fit (TBD)
      //  p[5] = 0.140068 shape parameter - rate of down slope
      //  p[6] = 87.7649 shape paramter - time of down slope relative to shape
      //  fit
      // These measurements can be used to fit the pulse shape if TOT is not
      // available. For now, we simply take the measurement of the SOI as the
      // peak amplitude.
 
      charge = (digi.soi().adc_t() - the_conditions.adcPedestal(id)) *
               the_conditions.adcGain(id);
 
      /* debug printout
      std::cout << "ADC Mode -> " << charge << " fC";
       */
    }
 
    if (charge < 0) continue;
 
    double num_mips_equivalent = charge / charge_per_mip_;
    double energy_deposited_in_Si = num_mips_equivalent * mip_si_energy_;
 
    /* debug printout
    std::cout << " -> " << num_mips_equivalent
        << " equiv MIPs -> " << energy_deposited_in_Si << " MeV"
        << std::endl;
     */
 
    // incorporate layer weights
    double reconstructed_energy =
        (num_mips_equivalent *
             layerWeights_.at(
                 id.layer())       // energy lost in non-sensitive layers
         + energy_deposited_in_Si  // energy deposited in Si itself
         ) *
        secondOrderEnergyCorrection_;
 
    // copy over information to rec hit structure in new collection
    ldmx::EcalHit recHit;
    recHit.setID(id.raw());
    recHit.setXPos(x);
    recHit.setYPos(y);
    recHit.setZPos(z);
    recHit.setAmplitude(energy_deposited_in_Si);
    recHit.setEnergy(reconstructed_energy);
    recHit.setTime(hitTime);
 
    ecalRecHits.push_back(recHit);
  }
 
  if (event.exists(simHitCollName_, simHitPassName_)) {
    // ecal sim hits exist ==> label which hits are real and which are pure
    // noise
    auto ecalSimHits{event.getCollection<ldmx::SimCalorimeterHit>(
        simHitCollName_, simHitPassName_)};
    std::set<int> real_hits;
    for (auto const& sim_hit : ecalSimHits) real_hits.insert(sim_hit.getID());
    for (auto& hit : ecalRecHits)
      hit.setNoise(real_hits.find(hit.getID()) == real_hits.end());
  }
 
  // add collection to event bus
  event.add(recHitCollName_, ecalRecHits);
}

References ecal::EcalReconConditions::adcGain(), ecal::EcalReconConditions::adcPedestal(), charge_per_mip_, clock_cycle_, ecal::EcalReconConditions::CONDITIONS_NAME, digiCollName_, digiPassName_, framework::Event::exists(), layerWeights_, mip_si_energy_, recHitCollName_, secondOrderEnergyCorrection_, ldmx::CalorimeterHit::setAmplitude(), ldmx::CalorimeterHit::setEnergy(), ldmx::CalorimeterHit::setID(), ldmx::CalorimeterHit::setTime(), ldmx::CalorimeterHit::setXPos(), ldmx::CalorimeterHit::setYPos(), ldmx::CalorimeterHit::setZPos(), simHitCollName_, simHitPassName_, ecal::EcalReconConditions::totGain(), and ecal::EcalReconConditions::totPedestal().

Member Data Documentation

charge_per_mip_

double ecal::EcalRecProducer::charge_per_mip_

private

Number of electrons generated by average MIP in Si 0.5mm thick.

Definition at line 83 of file EcalRecProducer.h.

Referenced by configure(), and produce().

clock_cycle_

double ecal::EcalRecProducer::clock_cycle_

private

Length of clock cycle [ns].

Definition at line 80 of file EcalRecProducer.h.

Referenced by configure(), and produce().

digiCollName_

std::string ecal::EcalRecProducer::digiCollName_

private

Digi Collection Name to use as input.

Definition at line 62 of file EcalRecProducer.h.

Referenced by configure(), and produce().

digiPassName_

std::string ecal::EcalRecProducer::digiPassName_

private

Digi Pass Name to use as input.

Definition at line 65 of file EcalRecProducer.h.

Referenced by configure(), and produce().

layerWeights_

std::vector<double> ecal::EcalRecProducer::layerWeights_

private

Layer Weights to use for this reconstruction.

Layer weights account for the energy lost in the absorber directly in front of the Silicon layer where the measured energy was deposited. These are determined by calculating the average amount of energy lost by a MIP passing through the extra material between sensitive layers.

Definition at line 93 of file EcalRecProducer.h.

Referenced by configure(), and produce().

mip_si_energy_

double ecal::EcalRecProducer::mip_si_energy_

private

Energy [MeV] deposited by a MIP in Si 0.5mm thick.

Definition at line 77 of file EcalRecProducer.h.

Referenced by configure(), and produce().

recHitCollName_

std::string ecal::EcalRecProducer::recHitCollName_

private

output hit collection name

Definition at line 74 of file EcalRecProducer.h.

Referenced by configure(), and produce().

secondOrderEnergyCorrection_

double ecal::EcalRecProducer::secondOrderEnergyCorrection_

private

Second Order Energy Correction to use for this reconstruction.

This is a shift applied to all of the energies in order to have the mean of the total energy deposited in the ECal be accurate. This is less physically motivated than the layer weights and is more of a calibration number.

Definition at line 103 of file EcalRecProducer.h.

Referenced by configure(), and produce().

simHitCollName_

std::string ecal::EcalRecProducer::simHitCollName_

private

simhit collection name

Definition at line 68 of file EcalRecProducer.h.

Referenced by configure(), and produce().

simHitPassName_

std::string ecal::EcalRecProducer::simHitPassName_

private

simhit pass name

Definition at line 71 of file EcalRecProducer.h.

Referenced by configure(), and produce().

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

• Ecal/include/Ecal/EcalRecProducer.h
• Ecal/src/Ecal/EcalRecProducer.cxx