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

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

protected

Definition at line 50 of file HcalSiPM.h.

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

protected

Definition at line 49 of file HcalSiPM.h.

Constructor & Destructor Documentation

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

Definition at line 14 of file HcalSiPM.cc.

References assert(), resetSiPM(), setTau(), and theCellCount.

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

HcalSiPM::~HcalSiPM ( )

virtual

Definition at line 23 of file HcalSiPM.cc.

23 {

24 }

Member Function Documentation

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

protected

Definition at line 81 of file HcalSiPM.cc.

References BorelCDF(), LogDebug, 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);
 }

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

protected

Definition at line 28 of file HcalSiPM.cc.

References b, create_public_lumi_plots::exp, dqm-mbProfile::log, 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;
 }

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

protected

Definition at line 46 of file HcalSiPM.cc.

References b, Borel(), borelcdfs, alignCSCRings::e, kinem::EPSILON, plotBeamSpotDB::first, i, 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;
 }

double HcalSiPM::cellCharge ( double deltaTime ) const

protected

Definition at line 182 of file HcalSiPM.cc.

References create_public_lumi_plots::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;
 }

double HcalSiPM::getCrossTalk ( ) const

inline

Definition at line 38 of file HcalSiPM.h.

References theCrossTalk.

38 { return theCrossTalk; }

HcalSiPM::theCrossTalk

double theCrossTalk

Definition: HcalSiPM.h:65

int HcalSiPM::getNCells ( ) const

inline

Definition at line 36 of file HcalSiPM.h.

References theCellCount.

36 { return theCellCount; }

HcalSiPM::theCellCount

unsigned int theCellCount

Definition: HcalSiPM.h:61

double HcalSiPM::getTau ( ) const

inline

Definition at line 37 of file HcalSiPM.h.

References theTau.

37 { return theTau; }

HcalSiPM::theTau

double theTau

Definition: HcalSiPM.h:63

double HcalSiPM::getTempDep ( ) const

inline

Definition at line 39 of file HcalSiPM.h.

References theTempDep.

39 { return theTempDep; }

HcalSiPM::theTempDep

double theTempDep

Definition: HcalSiPM.h:66

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(), 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;
 }

void HcalSiPM::resetSiPM ( )

inline

Definition at line 28 of file HcalSiPM.h.

References lumiContext::fill, and theSiPM.

Referenced by HcalSiPM(), and setNCells().

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

lumiContext.fill

string fill

Definition: lumiContext.py:319

HcalSiPM::theSiPM

std::vector< double > theSiPM

Definition: HcalSiPM.h:62

void HcalSiPM::setCrossTalk ( double xtalk )

Definition at line 157 of file HcalSiPM.cc.

References BorelCDF(), borelcdfs, relval_2017::k, and theCrossTalk.

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);
   }
 }

void HcalSiPM::setNCells ( int nCells )

Definition at line 144 of file HcalSiPM.cc.

References assert(), resetSiPM(), theCellCount, and theSiPM.

Referenced by HcalSiPMHitResponse::makeSiPMSignal().

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

void HcalSiPM::setSaturationPars ( const std::vector< float > & pars )

Definition at line 189 of file HcalSiPM.cc.

References nonlin.

Referenced by HcalSiPMHitResponse::makeSiPMSignal().

 {
   if (nonlin)
     delete nonlin;
 
   nonlin = new HcalSiPMnonlinearity(pars);
 }

void HcalSiPM::setTau ( double tau )

Definition at line 151 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;
 }

void HcalSiPM::setTemperatureDependence ( double tempDep )

Definition at line 177 of file HcalSiPM.cc.

References theTempDep.

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

virtual double HcalSiPM::totalCharge ( ) const

inlinevirtual

Definition at line 33 of file HcalSiPM.h.

References theLastHitTime, and totalCharge().

Referenced by totalCharge().

33 { return totalCharge(theLastHitTime); }

HcalSiPM::totalCharge

virtual double totalCharge() const

Definition: HcalSiPM.h:33

HcalSiPM::theLastHitTime

double theLastHitTime

Definition: HcalSiPM.h:67

double HcalSiPM::totalCharge ( double time ) const

virtual

Definition at line 133 of file HcalSiPM.cc.

References cellCharge(), i, theCellCount, and theSiPM.

                                               {
   // 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;
 }