HcalSiPM Class Reference

A general implementation for the response of a SiPM. More...

#include <HcalSiPM.h>

Public Member Functions
double	getCrossTalk () const
int	getNCells () const
double	getTau () const
double	getTempDep () const
	HcalSiPM (int nCells=1, double tau=15.)
virtual double	hitCells (CLHEP::HepRandomEngine *, unsigned int pes, double tempDiff=0., double photonTime=0.)
void	resetSiPM ()
void	setCrossTalk (double xtalk)
void	setNCells (int nCells)
void	setSaturationPars (const std::vector< float > &pars)
void	setTau (double tau)
void	setTemperatureDependence (double tempDep)
virtual double	totalCharge () const
virtual double	totalCharge (double time) const
virtual	~HcalSiPM ()

Protected Types
typedef std::unordered_map< unsigned int, cdfpair >	cdfmap
typedef std::pair< unsigned int, std::vector< double > >	cdfpair

Protected Member Functions
unsigned int	addCrossTalkCells (CLHEP::HepRandomEngine *engine, unsigned int in_pes)
double	Borel (unsigned int n, double lambda, unsigned int k)
const cdfpair &	BorelCDF (unsigned int k)
double	cellCharge (double deltaTime) const

Protected Attributes
cdfmap	borelcdfs
HcalSiPMnonlinearity *	nonlin
unsigned int	theCellCount
double	theCrossTalk
double	theLastHitTime
std::vector< double >	theSiPM
double	theTau
double	theTauInv
double	theTempDep

Detailed Description

A general implementation for the response of a SiPM.

Definition at line 22 of file HcalSiPM.h.

Member Typedef Documentation

cdfmap

typedef std::unordered_map<unsigned int, cdfpair> HcalSiPM::cdfmap

protected

Definition at line 47 of file HcalSiPM.h.

cdfpair

typedef std::pair<unsigned int, std::vector<double> > HcalSiPM::cdfpair

protected

Definition at line 46 of file HcalSiPM.h.

Constructor & Destructor Documentation

HcalSiPM()

HcalSiPM::HcalSiPM	(	int	nCells = 1,
		double	tau = 15.
	)

Definition at line 14 of file HcalSiPM.cc.

References cms::cuda::assert(), resetSiPM(), setTau(), metsig::tau, and theCellCount.

    : theCellCount(nCells), theSiPM(nCells, 1.), theCrossTalk(0.), theTempDep(0.), theLastHitTime(-1.), nonlin(nullptr) {
  setTau(tau);
  assert(theCellCount > 0);
  resetSiPM();
}

~HcalSiPM()

HcalSiPM::~HcalSiPM ( )

virtual

Definition at line 21 of file HcalSiPM.cc.

References nonlin.

                    {
  if (nonlin)
    delete nonlin;
}

Member Function Documentation

addCrossTalkCells()

unsigned int HcalSiPM::addCrossTalkCells ( CLHEP::HepRandomEngine *  engine, unsigned int  in_pes  )

protected

Definition at line 84 of file HcalSiPM.cc.

References BorelCDF(), LogDebug, pfDeepBoostedJetPreprocessParams_cfi::lower_bound, mitigatedMETSequence_cff::U, and up.

Referenced by hitCells().

                                                                                          {
  const cdfpair& cdf = BorelCDF(in_pes);

  double U = CLHEP::RandFlat::shoot(engine);
  std::vector<double>::const_iterator up;
  up = std::lower_bound(cdf.second.cbegin(), cdf.second.cend(), U);

  LogDebug("HcalSiPM") << "cdf size = " << cdf.second.size() << ", U = " << U << ", in_pes = " << in_pes
                       << ", 2ndary_pes = " << (up - cdf.second.cbegin() + cdf.first);

  // returns the number of secondary pes produced
  return (up - cdf.second.cbegin() + cdf.first);
}

Borel()

double HcalSiPM::Borel ( unsigned int  n, double  lambda, unsigned int  k  )

protected

Definition at line 28 of file HcalSiPM.cc.

References b, JetChargeProducer_cfi::exp, dqmdumpme::k, dqm-mbProfile::log, dqmiodumpmetadata::n, and funct::pow().

Referenced by BorelCDF().

                                                                    {
  if (n < k)
    return 0;
  double dn = double(n);
  double dk = double(k);
  double dnk = dn - dk;
  double ldn = lambda * dn;
  double logb = -ldn + dnk * log(ldn) - TMath::LnGamma(dnk + 1);
  double b = 0;
  if (logb >= -20) {  // protect against underflow
    b = (dk / dn);
    if ((n - k) < 100)
      b *= (exp(-ldn) * pow(ldn, dnk)) / TMath::Factorial(n - k);
    else
      b *= exp(logb);
  }
  return b;
}

BorelCDF()

const HcalSiPM::cdfpair & HcalSiPM::BorelCDF ( unsigned int  k )

protected

Definition at line 47 of file HcalSiPM.cc.

References b, Borel(), borelcdfs, MillePedeFileConverter_cfg::e, kinem::EPSILON, dqmdumpme::first, mps_fire::i, dqmdumpme::k, and theCrossTalk.

Referenced by addCrossTalkCells(), and setCrossTalk().

                                                        {
  // EPSILON determines the min and max # of xtalk cells that can be
  // simulated.
  static const double EPSILON = 1e-6;
  typename cdfmap::const_iterator it;
  it = borelcdfs.find(k);
  if (it == borelcdfs.end()) {
    vector<double> cdf;

    // Find the first n=k+i value for which cdf[i] > EPSILON
    unsigned int i;
    double b = 0., sumb = 0.;
    for (i = 0;; i++) {
      b = Borel(k + i, theCrossTalk, k);
      sumb += b;
      if (sumb >= EPSILON)
        break;
    }

    cdf.push_back(sumb);
    unsigned int borelstartn = i;

    // calculate cdf[i]
    for (++i;; ++i) {
      b = Borel(k + i, theCrossTalk, k);
      sumb += b;
      cdf.push_back(sumb);
      if (1 - sumb < EPSILON)
        break;
    }

    it = (borelcdfs.emplace(k, make_pair(borelstartn, cdf))).first;
  }

  return it->second;
}

cellCharge()

double HcalSiPM::cellCharge ( double  deltaTime ) const

protected

Definition at line 183 of file HcalSiPM.cc.

References JetChargeProducer_cfi::exp, mps_fire::result, and theTauInv.

Referenced by hitCells(), and totalCharge().

                                                  {
  if (deltaTime <= 0.)
    return 0.;
  if (deltaTime * theTauInv > 10.)
    return 1.;
  double result(1. - std::exp(-deltaTime * theTauInv));
  return (result > 0.99) ? 1.0 : result;
}

getCrossTalk()

double HcalSiPM::getCrossTalk ( ) const

inline

Definition at line 36 of file HcalSiPM.h.

References theCrossTalk.

{ return theCrossTalk; }

getNCells()

int HcalSiPM::getNCells ( ) const

inline

Definition at line 34 of file HcalSiPM.h.

References theCellCount.

{ return theCellCount; }

getTau()

double HcalSiPM::getTau ( ) const

inline

Definition at line 35 of file HcalSiPM.h.

References theTau.

{ return theTau; }

getTempDep()

double HcalSiPM::getTempDep ( ) const

inline

Definition at line 37 of file HcalSiPM.h.

References theTempDep.

{ return theTempDep; }

hitCells()

double HcalSiPM::hitCells ( CLHEP::HepRandomEngine *  engine, unsigned int  pes, double  tempDiff = 0., double  photonTime = 0.  )

virtual

Definition at line 100 of file HcalSiPM.cc.

References addCrossTalkCells(), cellCharge(), muonClassificationByHits_cfi::pixel, theCellCount, theCrossTalk, theLastHitTime, theSiPM, theTau, and theTempDep.

Referenced by HcalSiPMHitResponse::makeSiPMSignal().

                                                                                                            {
  // response to light impulse with pes input photons.  The return is the number
  // of micro-pixels hit.  If a fraction other than 0. is supplied then the
  // micro-pixel doesn't fully discharge.  The tempDiff is the temperature
  // difference from nominal and is used to modify the relative strength of a
  // hit pixel.  Pixels which are fractionally charged return a fractional
  // number of hit pixels.

  if ((theCrossTalk > 0.) && (theCrossTalk < 1.))
    pes += addCrossTalkCells(engine, pes);

  // Account for saturation - disabled in lieu of recovery model below
  //pes = nonlin->getPixelsFired(pes);

  //disable saturation/recovery model for bad tau values
  if (theTau <= 0)
    return pes;

  unsigned int pixel;
  double sum(0.), hit(0.);
  for (unsigned int pe(0); pe < pes; ++pe) {
    pixel = CLHEP::RandFlat::shootInt(engine, theCellCount);
    hit = (theSiPM[pixel] < 0.) ? 1.0 : (cellCharge(photonTime - theSiPM[pixel]));
    sum += hit * (1 + (tempDiff * theTempDep));
    theSiPM[pixel] = photonTime;
  }

  theLastHitTime = photonTime;

  return sum;
}

resetSiPM()

void HcalSiPM::resetSiPM ( )

inline

Definition at line 28 of file HcalSiPM.h.

References ntuplemaker::fill, and theSiPM.

Referenced by HcalSiPM(), and setNCells().

{ std::fill(theSiPM.begin(), theSiPM.end(), -999.); }

setCrossTalk()

void HcalSiPM::setCrossTalk

(

double

xtalk

)

Definition at line 158 of file HcalSiPM.cc.

References BorelCDF(), borelcdfs, dqmdumpme::k, theCrossTalk, and hgchebackDigitizer_cfi::xTalk.

Referenced by HcalSiPMHitResponse::makeSiPMSignal().

                                        {
  // set the cross-talk probability

  double oldCrossTalk = theCrossTalk;

  if ((xTalk < 0) || (xTalk >= 1)) {
    theCrossTalk = 0.;
  } else {
    theCrossTalk = xTalk;
  }

  // Recalculate the crosstalk CDFs
  if (theCrossTalk != oldCrossTalk) {
    borelcdfs.clear();
    if (theCrossTalk > 0)
      for (int k = 1; k <= 100; k++)
        BorelCDF(k);
  }
}

setNCells()

void HcalSiPM::setNCells

(

int

nCells

)

Definition at line 143 of file HcalSiPM.cc.

References cms::cuda::assert(), caHitNtupletGeneratorKernels::nCells, resetSiPM(), theCellCount, and theSiPM.

Referenced by HcalSiPMHitResponse::makeSiPMSignal().

                                   {
  assert(nCells > 0);
  theCellCount = nCells;
  theSiPM.resize(nCells);
  resetSiPM();
}

setSaturationPars()

void HcalSiPM::setSaturationPars

(

const std::vector< float > &

pars

)

Definition at line 192 of file HcalSiPM.cc.

References nonlin.

Referenced by HcalSiPMHitResponse::makeSiPMSignal().

                                                             {
  if (nonlin)
    delete nonlin;

  nonlin = new HcalSiPMnonlinearity(pars);
}

setTau()

void HcalSiPM::setTau

(

double

tau

)

Definition at line 150 of file HcalSiPM.cc.

References metsig::tau, theTau, and theTauInv.

Referenced by HcalSiPM(), and HcalSiPMHitResponse::makeSiPMSignal().

                                {
  theTau = tau;
  if (theTau > 0)
    theTauInv = 1. / theTau;
  else
    theTauInv = 0;
}

setTemperatureDependence()

void HcalSiPM::setTemperatureDependence

(

double

tempDep

)

Definition at line 178 of file HcalSiPM.cc.

References theTempDep.

                                                    {
  // set the temperature dependence
  theTempDep = dTemp;
}

totalCharge() [1/2]

virtual double HcalSiPM::totalCharge ( ) const

inlinevirtual

Definition at line 31 of file HcalSiPM.h.

References theLastHitTime, and totalCharge().

Referenced by totalCharge().

{ return totalCharge(theLastHitTime); }

totalCharge() [2/2]

double HcalSiPM::totalCharge ( double  time ) const

virtual

Definition at line 132 of file HcalSiPM.cc.

References cellCharge(), mps_fire::i, theCellCount, theSiPM, protons_cff::time, and compareTotals::tot.

                                              {
  // sum of the micro-pixels.  NP is a fully charged device.
  // 0 is a fullly depleted device.
  double tot(0.), hit(0.);
  for (unsigned int i = 0; i < theCellCount; ++i) {
    hit = (theSiPM[i] < 0.) ? 1. : cellCharge(time - theSiPM[i]);
    tot += hit;
  }
  return tot;
}

Member Data Documentation

borelcdfs

cdfmap HcalSiPM::borelcdfs

protected

Definition at line 68 of file HcalSiPM.h.

Referenced by BorelCDF(), and setCrossTalk().

nonlin

HcalSiPMnonlinearity* HcalSiPM::nonlin

protected

Definition at line 66 of file HcalSiPM.h.

Referenced by setSaturationPars(), and ~HcalSiPM().

theCellCount

unsigned int HcalSiPM::theCellCount

protected

Definition at line 58 of file HcalSiPM.h.

Referenced by getNCells(), HcalSiPM(), hitCells(), setNCells(), and totalCharge().

theCrossTalk

double HcalSiPM::theCrossTalk

protected

Definition at line 62 of file HcalSiPM.h.

Referenced by BorelCDF(), getCrossTalk(), hitCells(), and setCrossTalk().

theLastHitTime

double HcalSiPM::theLastHitTime

protected

Definition at line 64 of file HcalSiPM.h.

Referenced by hitCells(), and totalCharge().

theSiPM

std::vector<double> HcalSiPM::theSiPM

protected

Definition at line 59 of file HcalSiPM.h.

Referenced by hitCells(), resetSiPM(), setNCells(), and totalCharge().

theTau

double HcalSiPM::theTau

protected

Definition at line 60 of file HcalSiPM.h.

Referenced by getTau(), hitCells(), and setTau().

theTauInv

double HcalSiPM::theTauInv

protected

Definition at line 61 of file HcalSiPM.h.

Referenced by cellCharge(), and setTau().

theTempDep

double HcalSiPM::theTempDep

protected

Definition at line 63 of file HcalSiPM.h.

Referenced by getTempDep(), hitCells(), and setTemperatureDependence().