CSCWireElectronicsSim Class Reference

#include <CSCWireElectronicsSim.h>

Inheritance diagram for CSCWireElectronicsSim:

Public Member Functions
	CSCWireElectronicsSim (const edm::ParameterSet &p)
	configurable parameters More...
void	fillDigis (CSCWireDigiCollection &digis, CLHEP::HepRandomEngine *)
void	setFraction (float newFraction)
Public Member Functions inherited from CSCBaseElectronicsSim
const DigiSimLinks &	digiSimLinks () const
void	setLayerId (const CSCDetId &id)
	for standalone apps who don't calculate it from the geometry More...
void	simulate (const CSCLayer *layer, const std::vector< CSCDetectorHit > &inputHits, CLHEP::HepRandomEngine *)
virtual	~CSCBaseElectronicsSim ()

Private Member Functions
float	calculateAmpResponse (float t) const override
int	channelIndex (int channel) const override
	we code strip indices from 1-80, and wire indices start at 100 More...
void	initParameters () override
	initialization for each layer More...
int	readoutElement (int element) const override
virtual float	timeOfFlightCalibration (int wireGroup) const

Private Attributes
float	theFraction
float	theWireNoise
float	theWireThreshold

Additional Inherited Members
Public Types inherited from CSCBaseElectronicsSim
typedef std::map< int, CSCAnalogSignal, std::less< int > >	CSCSignalMap
typedef edm::DetSet< StripDigiSimLink >	DigiSimLinks
Protected Types inherited from CSCBaseElectronicsSim
enum	{ NONE, CONSERVATIVE, RADICAL }
typedef std::multimap< int, CSCDetectorHit, std::less< int > >	DetectorHitMap
Protected Member Functions inherited from CSCBaseElectronicsSim
CSCAnalogSignal &	add (const CSCAnalogSignal &, CLHEP::HepRandomEngine *)
virtual void	addLinks (int channelIndex)
void	addNoise (CLHEP::HepRandomEngine *)
CSCAnalogSignal	amplifySignal (const CSCDetectorHit &)
double	averageTimeOfFlight (const DetId &detId) const
void	combineAnalogSignals (const std::vector< CSCAnalogSignal > &)
	CSCBaseElectronicsSim (const edm::ParameterSet &p)
void	fillAmpResponse ()
CSCAnalogSignal &	find (int element, CLHEP::HepRandomEngine *)
CSCDetId	layerId () const
	the CSCDetId corresponding to the current layer More...
virtual CSCAnalogSignal	makeNoiseSignal (int element, CLHEP::HepRandomEngine *)
void	setLayer (const CSCLayer *layer)
void	setNoise (float rmsNoise, float noiseSigmaThreshold)
void	setSignalTimeRange (double startTime, double stopTime)
virtual float	signalDelay (int element, float pos) const
Protected Attributes inherited from CSCBaseElectronicsSim
bool	doNoise_
int	nElements
CSCAnalogSignal	theAmpResponse
float	theBunchSpacing
std::vector< double >	theBunchTimingOffsets
DetectorHitMap	theDetectorHitMap
DigiSimLinks	theDigiSimLinks
const CSCLayer *	theLayer
const CSCLayerGeometry *	theLayerGeometry
CSCDetId	theLayerId
bool	theNoiseWasAdded
int	theNumberOfSamples
int	theOffsetOfBxZero
float	thePeakTimeSigma
float	theSamplingTime
int	theShapingTime
CSCSignalMap	theSignalMap
std::vector< double >	theSignalPropagationSpeed
float	theSignalStartTime
float	theSignalStopTime
const CSCChamberSpecs *	theSpecs
std::vector< double >	theTimingCalibrationError

Detailed Description

Model the readout electronics chain for EMU CSC wires

Author

Rick Wilkinson

Definition at line 20 of file CSCWireElectronicsSim.h.

Constructor & Destructor Documentation

CSCWireElectronicsSim()

CSCWireElectronicsSim::CSCWireElectronicsSim

(

const edm::ParameterSet &

p

)

configurable parameters

Definition at line 15 of file CSCWireElectronicsSim.cc.

References CSCBaseElectronicsSim::fillAmpResponse().

    : CSCBaseElectronicsSim(p), theFraction(0.5), theWireNoise(0.0), theWireThreshold(0.) {
  fillAmpResponse();
}

Member Function Documentation

calculateAmpResponse()

float CSCWireElectronicsSim::calculateAmpResponse ( float  t ) const

overrideprivatevirtual

Implements CSCBaseElectronicsSim.

Definition at line 144 of file CSCWireElectronicsSim.cc.

References Calorimetry_cff::dp, JetChargeProducer_cfi::exp, LaserDQM_cfg::p1, funct::pow(), and submitPVValidationJobs::t.

                                                               {
  static const float fC_by_ns = 1000000;
  static const float resistor = 20000;
  static const float amplifier_pole = 1 / 7.5;
  static const float fastest_chamber_exp_risetime = 10.;
  static const float p0 = amplifier_pole;
  static const float p1 = 1 / fastest_chamber_exp_risetime;

  static const float dp = p0 - p1;

  // ENABLE DISC:

  static const float norm = -12 * resistor * p1 * pow(p0 / dp, 4) / fC_by_ns;

  float enable_disc_volts =
      norm * (exp(-p0 * t) * (1 + t * dp + pow(t * dp, 2) / 2 + pow(t * dp, 3) / 6) - exp(-p1 * t));
  static const float collectionFraction = 0.12;
  static const float igain = 1. / 0.005;  // volts per fC
  return enable_disc_volts * igain * collectionFraction;
}

channelIndex()

int CSCWireElectronicsSim::channelIndex ( int  channel ) const

inlineoverrideprivatevirtual

we code strip indices from 1-80, and wire indices start at 100

Reimplemented from CSCBaseElectronicsSim.

Definition at line 41 of file CSCWireElectronicsSim.h.

Referenced by fillDigis().

{ return channel + 100; }

fillDigis()

void CSCWireElectronicsSim::fillDigis	(	CSCWireDigiCollection &	digis,
		CLHEP::HepRandomEngine *	engine
	)

Definition at line 28 of file CSCWireElectronicsSim.cc.

References CSCBaseElectronicsSim::addLinks(), CSCChamberSpecs::chamberType(), nano_mu_digi_cff::chamberType, channelIndex(), CSCBaseElectronicsSim::doNoise_, CSCAnalogSignal::getBinValue(), CSCAnalogSignal::getSize(), mps_fire::i, CSCBaseElectronicsSim::layerId(), LogTrace, CSCBaseElectronicsSim::theBunchSpacing, CSCBaseElectronicsSim::theBunchTimingOffsets, theFraction, CSCBaseElectronicsSim::theOffsetOfBxZero, CSCBaseElectronicsSim::theSamplingTime, CSCBaseElectronicsSim::theSignalMap, CSCBaseElectronicsSim::theSignalStartTime, CSCBaseElectronicsSim::theSpecs, CSCBaseElectronicsSim::theTimingCalibrationError, theWireNoise, theWireThreshold, DiMuonV_cfg::threshold, timeOfFlightCalibration(), and nano_mu_digi_cff::wireGroup.

Referenced by CSCDigitizer::doAction().

                                                                                                {
  if (theSignalMap.empty()) {
    return;
  }

  // Loop over analog signals, run the fractional discriminator on each one,
  // and save the DIGI in the layer.
  for (CSCSignalMap::iterator mapI = theSignalMap.begin(), lastSignal = theSignalMap.end(); mapI != lastSignal;
       ++mapI) {
    int wireGroup = (*mapI).first;
    const CSCAnalogSignal &signal = (*mapI).second;
    LogTrace("CSCWireElectronicsSim") << "CSCWireElectronicsSim: dump of wire signal follows... " << signal;
    int signalSize = signal.getSize();

    int timeWord = 0;  // and this will remain if too early or late (<bx-6 or >bx+9)

    // the way we handle noise in this chamber is by randomly varying
    // the threshold
    float threshold = theWireThreshold;
    if (doNoise_) {
      threshold += CLHEP::RandGaussQ::shoot(engine) * theWireNoise;
    }
    for (int ibin = 0; ibin < signalSize; ++ibin) {
      if (signal.getBinValue(ibin) > threshold) {
        // jackpot.  Now define this signal as everything up until
        // the signal goes below zero.
        int lastbin = signalSize;
        int i;
        for (i = ibin; i < signalSize; ++i) {
          if (signal.getBinValue(i) < 0.) {
            lastbin = i;
            break;
          }
        }

        float qMax = 0.0;
        // in this loop, find the max charge and the 'fifth' electron arrival
        for (i = ibin; i < lastbin; ++i) {
          float next_charge = signal.getBinValue(i);
          if (next_charge > qMax) {
            qMax = next_charge;
          }
        }

        int bin_firing_FD = 0;
        for (i = ibin; i < lastbin; ++i) {
          if (signal.getBinValue(i) >= qMax * theFraction) {
            bin_firing_FD = i;
            //@@ Long-standing but unlikely minor bug, I (Tim) think - following
            //'break' was missing...
            //@@ ... So if both ibins 0 and 1 could fire FD, we'd flag the
            // firing bin as 1 not 0
            //@@ (since the above test was restricted to bin_firing_FD==0 too).
            break;
          }
        }

        float tofOffset = timeOfFlightCalibration(wireGroup);
        int chamberType = theSpecs->chamberType();

        // Note that CSCAnalogSignal::superimpose does not reset theTimeOffset
        // to the earliest of the two signal's time offsets. If it did then we
        // could handle signals from any time range e.g. form pileup events many
        // bx's from the signal bx (bx=0). But then we would be wastefully
        // storing signals over times which we can never see in the real
        // detector, because only hits within a few bx's of bx=0 are read out.
        // Instead, the working time range for wire hits is always started from
        // theSignalStartTime, set as a parameter in the config file.
        // On the other hand, if any of the overlapped CSCAnalogSignals happens
        // to have a timeOffset earlier than theSignalStartTime (which is
        // currently set to -100 ns) then we're in trouble. For pileup events
        // this would mean events from collisions earlier than 4 bx before the
        // signal bx.

        float fdTime = theSignalStartTime + theSamplingTime * bin_firing_FD;
        if (doNoise_) {
          fdTime += theTimingCalibrationError[chamberType] * CLHEP::RandGaussQ::shoot(engine);
        }

        float bxFloat = (fdTime - tofOffset - theBunchTimingOffsets[chamberType]) / theBunchSpacing + theOffsetOfBxZero;
        int bxInt = static_cast<int>(bxFloat);
        if (bxFloat >= 0 && bxFloat < 16) {
          timeWord |= (1 << bxInt);
          // discriminator stays high for 35 ns
          if (bxFloat - bxInt > 0.6) {
            timeWord |= (1 << (bxInt + 1));
          }
        }

        // Wire digi as of Oct-2006 adapted to real data: time word has 16 bits
        // with set bit flagging appropriate bunch crossing, and bx 0
        // corresponding to the 7th bit, 'bit 6':

        //      1st bit set (bit 0) <-> bx -6
        //      2nd              1  <-> bx -5
        //      ...           ...       ....
        //      7th              6  <-> bx  0
        //      8th              7  <-> bx +1
        //      ...           ...       ....
        //     16th             15  <-> bx +9

        // skip over all the time bins used for this digi
        ibin = lastbin;
      }  // if over threshold
    }  // loop over time bins in signal

    // Only create a wire digi if there is a wire hit within [-6 bx, +9 bx]
    if (timeWord != 0) {
      CSCWireDigi newDigi(wireGroup, timeWord);
      LogTrace("CSCWireElectronicsSim") << "CSCWireElectronicsSim: " << newDigi;
      digis.insertDigi(layerId(), newDigi);
      addLinks(channelIndex(wireGroup));
    }
  }  // loop over wire signals
}

initParameters()

void CSCWireElectronicsSim::initParameters ( )

overrideprivatevirtual

initialization for each layer

Implements CSCBaseElectronicsSim.

Definition at line 20 of file CSCWireElectronicsSim.cc.

References e_SI, CSCBaseElectronicsSim::nElements, CSCLayerGeometry::numberOfWireGroups(), funct::pow(), CSCBaseElectronicsSim::theLayerGeometry, CSCBaseElectronicsSim::theShapingTime, CSCBaseElectronicsSim::theSpecs, theWireNoise, theWireThreshold, and CSCChamberSpecs::wireNoise().

                                           {
  nElements = theLayerGeometry->numberOfWireGroups();
  theWireNoise = theSpecs->wireNoise(theShapingTime) * CLHEP::e_SI * pow(10.0, 15);
  theWireThreshold = theWireNoise * 8;
}

readoutElement()

int CSCWireElectronicsSim::readoutElement ( int  element ) const

overrideprivatevirtual

Implements CSCBaseElectronicsSim.

Definition at line 26 of file CSCWireElectronicsSim.cc.

References CSCBaseElectronicsSim::theLayerGeometry, and CSCLayerGeometry::wireGroup().

{ return theLayerGeometry->wireGroup(element); }

setFraction()

void CSCWireElectronicsSim::setFraction ( float  newFraction )

inline

Definition at line 25 of file CSCWireElectronicsSim.h.

References theFraction.

{ theFraction = newFraction; };

timeOfFlightCalibration()

float CSCWireElectronicsSim::timeOfFlightCalibration ( int  wireGroup ) const

privatevirtual

Definition at line 165 of file CSCWireElectronicsSim.cc.

References CSCLayer::centerOfWireGroup(), LogTrace, PV3DBase< T, PVType, FrameType >::mag(), CSCLayerGeometry::numberOfWireGroups(), CSCBaseElectronicsSim::theLayer, CSCBaseElectronicsSim::theLayerGeometry, and nano_mu_digi_cff::wireGroup.

Referenced by fillDigis().

                                                                        {
  // calibration is done for groups of 8 wire groups, facetiously
  // called wireGroupGroups
  int middleWireGroup = wireGroup - wireGroup % 8 + 4;
  int numberOfWireGroups = theLayerGeometry->numberOfWireGroups();
  if (middleWireGroup > numberOfWireGroups)
    middleWireGroup = numberOfWireGroups;

  GlobalPoint centerOfGroupGroup = theLayer->centerOfWireGroup(middleWireGroup);
  float averageDist = centerOfGroupGroup.mag();
  float averageTOF = averageDist * CLHEP::cm / c_light;  // Units of c_light: mm/ns

  LogTrace("CSCWireElectronicsSim") << "CSCWireElectronicsSim: TofCalib  wg = " << wireGroup
                                    << " mid wg = " << middleWireGroup << " av dist = " << averageDist
                                    << " av tof = " << averageTOF;

  return averageTOF;
}

Member Data Documentation

theFraction

float CSCWireElectronicsSim::theFraction

private

Definition at line 46 of file CSCWireElectronicsSim.h.

Referenced by fillDigis(), and setFraction().

theWireNoise

float CSCWireElectronicsSim::theWireNoise

private

Definition at line 47 of file CSCWireElectronicsSim.h.

Referenced by fillDigis(), and initParameters().

theWireThreshold

float CSCWireElectronicsSim::theWireThreshold

private

Definition at line 48 of file CSCWireElectronicsSim.h.

Referenced by fillDigis(), and initParameters().