CSCGasCollisions Class Reference

#include <CSCGasCollisions.h>

Public Member Functions
	CSCGasCollisions (const edm::ParameterSet &pset)
bool	dumpGasCollisions (void) const
bool	saveGasCollisions (void) const
void	setParticleDataTable (const ParticleDataTable *pdt)
void	simulate (const PSimHit &, std::vector< LocalPoint > &clusters, std::vector< int > &electrons, CLHEP::HepRandomEngine *)
virtual	~CSCGasCollisions ()

Static Public Attributes
static const int	MAX_STEPS = 400
static const int	N_ENERGY = 63
static const int	N_ENTRIES = N_GAMMA * N_ENERGY
static const int	N_GAMMA = 21

Private Member Functions
void	fillCollisionsForThisGamma (float, std::vector< float > &) const
float	generateEnergyLoss (double avCollisions, double anmin, double anmax, const std::vector< float > &collisions, CLHEP::HepRandomEngine *) const
double	generateStep (double avCollisions, CLHEP::HepRandomEngine *) const
void	ionize (double energyTransferred, LocalPoint startHere) const
float	lnEnergyLoss (float, const std::vector< float > &) const
void	readCollisionTable ()
void	writeSummary (int n_try, int n_steps, double sum_steps, float dedx, const PSimHit &simhit) const

Private Attributes
double	clusterExtent
double	deCut
bool	dumpGasCollisions_
double	eion
double	ework
double	gasDensity
const std::string	me
bool	saveGasCollisions_
std::vector< float >	theCollisionTable
CSCCrossGap *	theCrossGap
std::vector< float >	theEnergyBins
std::vector< float >	theGammaBins
const ParticleDataTable *	theParticleDataTable

Detailed Description

Class to handle CSC gas ionization simulation during digitization.

Author

Tim Cox

This class contains the port of the old CMSIM/ORCA Fortran routine mc_clus.F, and the GEANT3 code it relied on. Of course the version here is much improved :)

Definition at line 27 of file CSCGasCollisions.h.

Constructor & Destructor Documentation

CSCGasCollisions()

CSCGasCollisions::CSCGasCollisions

(

const edm::ParameterSet &

pset

)

Definition at line 58 of file CSCGasCollisions.cc.

    : me("CSCGasCollisions"),
      gasDensity(2.1416e-03),
      deCut(1.e05),
      eion(14.95),
      ework(34.0),
      clusterExtent(0.001),
      theGammaBins(N_GAMMA, 0.),
      theEnergyBins(N_ENERGY, 0.),
      theCollisionTable(N_ENTRIES, 0.),
      theCrossGap(nullptr),
      theParticleDataTable(nullptr),
      saveGasCollisions_(false),
      dumpGasCollisions_(false) {
  dumpGasCollisions_ = pset.getUntrackedParameter<bool>("dumpGasCollisions");
 
  edm::LogInfo(me) << "Constructing a " << me << ":";
  edm::LogInfo(me) << "gas density = " << gasDensity << " g/cm3";
  edm::LogInfo(me) << "max eloss per collision allowed = " << deCut / 1000.
                   << " keV (for higher elosses, hits should have been simulated.)";
  edm::LogInfo(me) << "ionization threshold = " << eion << " eV";
  edm::LogInfo(me) << "effective work function = " << ework << " eV";
  edm::LogInfo(me) << "cluster extent = " << clusterExtent * 1.e04 << " micrometres";
  edm::LogInfo(me) << "dump gas collision and simhit information? " << dumpGasCollisions();
  edm::LogInfo(me) << "save gas collision information? -NOT YET IMPLEMENTED- " << saveGasCollisions();
 
  readCollisionTable();
}

References clusterExtent, deCut, dumpGasCollisions(), dumpGasCollisions_, eion, ework, gasDensity, me, muonDTDigis_cfi::pset, readCollisionTable(), and saveGasCollisions().

~CSCGasCollisions()

CSCGasCollisions::~CSCGasCollisions ( )

virtual

Definition at line 87 of file CSCGasCollisions.cc.

                                    {
  edm::LogInfo(me) << "Destructing a " << me;
  delete theCrossGap;
}

References me, and theCrossGap.

Member Function Documentation

dumpGasCollisions()

bool CSCGasCollisions::dumpGasCollisions ( void  ) const

inline

Definition at line 39 of file CSCGasCollisions.h.

{ return dumpGasCollisions_; }

References dumpGasCollisions_.

Referenced by CSCGasCollisions(), generateEnergyLoss(), generateStep(), and simulate().

fillCollisionsForThisGamma()

void CSCGasCollisions::fillCollisionsForThisGamma ( float  logGamma, std::vector< float > &  collisions  ) const

private

Definition at line 551 of file CSCGasCollisions.cc.

                                                                                                    {
  std::vector<float>::const_iterator bigger =
      find_if(theGammaBins.begin(), theGammaBins.end(), [&logGamma](auto c) { return c > logGamma; });
 
  if (bigger == theGammaBins.end()) {
    // use highest bin
    LogTrace(me) << ": using highest gamma bin"
                 << " for logGamma = " << logGamma;
    for (int i = 0; i < N_ENERGY; ++i)
      collisions[i] = theCollisionTable[i * N_GAMMA];
  } else {
    // use bigger and its lower neighbour
    std::vector<float>::difference_type ihi = bigger - theGammaBins.begin();
    if (ihi > 0) {
      double dlg2 = *bigger--;  // and decrement after deref
      // LogTrace(me) << ": using gamma bins "
      //                   << ihi-1 << " and " << ihi;
      double dlg1 = *bigger;  // now the preceding element
      double dlg = (logGamma - dlg1) / (dlg2 - dlg1);
      double omdlg = 1. - dlg;
      for (int i = 0; i < N_ENERGY; ++i)
        collisions[i] = theCollisionTable[i * N_GAMMA + ihi - 1] * omdlg + theCollisionTable[i * N_GAMMA + ihi] * dlg;
    } else {
      // bigger has no lower neighbour
      LogTrace(me) << ": using lowest gamma bin"
                   << " for logGamma = " << logGamma;
 
      for (int i = 0; i < N_ENERGY; ++i)
        collisions[i] = theCollisionTable[i * N_GAMMA];
    }
  }
}

References c, mps_fire::i, LogTrace, me, N_ENERGY, N_GAMMA, theCollisionTable, and theGammaBins.

Referenced by simulate().

generateEnergyLoss()

float CSCGasCollisions::generateEnergyLoss ( double  avCollisions, double  anmin, double  anmax, const std::vector< float > &  collisions, CLHEP::HepRandomEngine *  engine  ) const

private

Definition at line 294 of file CSCGasCollisions.cc.

                                                                               {
  // Generate a no. of collisions between collisions[0] and [N_ENERGY-1]
  float lnColl = log(CLHEP::RandFlat::shoot(engine, anmin, anmax));
 
  // Without using CLHEP: approx random between anmin and anmax
  //    double ra = double(rand())/double(RAND_MAX)*avCollisions;
  //    cout << "ra = " << ra << std::endl;
  //    float lnColl = static_cast<float>( log( ra ) );
 
  // Find energy loss for that number
  float lnE = lnEnergyLoss(lnColl, collisions);
  float eloss = exp(lnE);
  // Compensate if gamma was actually below 1.1
  if (theCrossGap->gamma() < 1.1)
    eloss = eloss * 0.173554 / theCrossGap->beta2();
  LogTrace(me) << "eloss = " << eloss << " eV";
  // Next line only used to fill container of eloss's for later diagnostic dumps
  if (dumpGasCollisions())
    theCrossGap->addEloss(eloss);
  return eloss;
}

References CSCCrossGap::addEloss(), CSCCrossGap::beta2(), dumpGasCollisions(), JetChargeProducer_cfi::exp, CSCCrossGap::gamma(), lnEnergyLoss(), dqm-mbProfile::log, LogTrace, me, and theCrossGap.

Referenced by simulate().

generateStep()

double CSCGasCollisions::generateStep ( double  avCollisions, CLHEP::HepRandomEngine *  engine  ) const

private

Definition at line 278 of file CSCGasCollisions.cc.

                                                                                             {
  // Generate a m.f.p.  (1/avCollisions = cm/collision)
  double step = (CLHEP::RandExponential::shoot(engine)) / avCollisions;
 
  // Without using CLHEP: approx random exponential by...
  //    double da = double(rand())/double(RAND_MAX);
  //    double step = -log(1.-da)/avCollisions;
 
  LogTrace(me) << " step = " << step << " cm";
  // Next line only used to fill a container of 'step's for later diagnostic
  // dumps
  if (dumpGasCollisions())
    theCrossGap->addStep(step);
  return step;
}

References CSCCrossGap::addStep(), dumpGasCollisions(), LogTrace, me, and theCrossGap.

Referenced by simulate().

ionize()

void CSCGasCollisions::ionize ( double  energyTransferred, LocalPoint  startHere  ) const

private

Definition at line 320 of file CSCGasCollisions.cc.

                                                                                {
  while (energyAvailable > eion) {
    LogTrace(me) << "     NEW CLUSTER " << theCrossGap->noOfClusters() + 1 << " AT " << startHere;
    LocalPoint newCluster(startHere);
    theCrossGap->addCluster(newCluster);
 
    //@@ I consider NOT subtracting eion before calculating range to be a bug.
    //@@ But this changes tuning of the algorithm so leave it until after the
    // big rush to 7_5_0
    //@@  energyAvailable -= eion;
 
    // Sauli CERN 77-09: delta e range with E in MeV (Sauli references Kobetich
    // & Katz 1968 but that has nothing to do with this expression! He seems to
    // have  made a mistake.) I found the Sauli-quoted relationship in R.
    // Glocker, Z. Naturforsch. Ba, 129 (1948): delta e range R = aE^n with
    // a=710, n=1.72 for E in MeV and R in mg/cm^2 applicable over the range E =
    // 0.001 to 0.3 MeV.
 
    // Take HALF that range. //@@ Why? Why not...
    double range = 0.5 * (0.71 / gasDensity) * pow(energyAvailable * 1.E-6, 1.72);
    LogTrace(me) << " range = " << range << " cm";
    if (range < clusterExtent) {
      // short-range delta e
      // How many electrons can we make? Now use *average* energy for ionization
      // (not *minimum*)
      int nelec = static_cast<int>(energyAvailable / ework);
      LogTrace(me) << "short-range delta energy in = " << energyAvailable << " eV";
      // energyAvailable -= nelec*(energyAvailable/ework);
      energyAvailable -= nelec * ework;
      // If still above eion (minimum, not average) add one more e
      if (energyAvailable > eion) {
        ++nelec;
        energyAvailable -= eion;
      }
      LogTrace(me) << "short-range delta energy out = " << energyAvailable << " eV, nelec = " << nelec;
      theCrossGap->addElectrons(nelec);
      break;
 
    } else {
      // long-range delta e
      LogTrace(me) << "long-range delta \n"
                   << "no. of electrons in cluster now = " << theCrossGap->noOfElectrons();
      theCrossGap->addElectrons(1);  // Position is at startHere still
 
      bool new_range = false;
      while (!new_range && (energyAvailable > ework)) {
        energyAvailable -= ework;
        while (energyAvailable > eion) {
          double range2 = 0.5 * 0.71 / gasDensity * pow(1.E-6 * energyAvailable, 1.72);
          double drange = range - range2;
          LogTrace(me) << "  energy left = " << energyAvailable << " eV, range2 = " << range2
                       << " cm, drange = " << drange << " cm";
          if (drange < clusterExtent) {
            theCrossGap->addElectronToBack();  // increment last element
          } else {
            startHere += drange * theCrossGap->unitVector();  // update delta e start position
            range = range2;                                   // update range
            new_range = true;                                 // Test range again
            LogTrace(me) << "reset range to range2 = " << range << " from startHere = " << startHere << "  and iterate";
          }
          break;  // out of inner while energyAvailable>eion
 
        }  // inner while energyAvailable>eion
 
      }  // while !new_range && energyAvailable>ework
 
      // energyAvailable now less than ework, but still may be over eion...add
      // an e
      if (energyAvailable > eion) {
        energyAvailable -= ework;          // yes, it may go negative
        theCrossGap->addElectronToBack();  // add one more e
      }
 
    }  // if range
 
  }  // outer while energyAvailable>eion
}

References CSCCrossGap::addCluster(), CSCCrossGap::addElectrons(), CSCCrossGap::addElectronToBack(), clusterExtent, eion, ework, gasDensity, LogTrace, me, CSCCrossGap::noOfClusters(), CSCCrossGap::noOfElectrons(), funct::pow(), FastTimerService_cff::range, theCrossGap, and CSCCrossGap::unitVector().

Referenced by simulate().

lnEnergyLoss()

float CSCGasCollisions::lnEnergyLoss ( float  lnCollisions, const std::vector< float > &  collisions  ) const

private

Definition at line 520 of file CSCGasCollisions.cc.

                                                                                                 {
  float lnE = -1.;
 
  // Find collision[] bin in which lnCollisions falls
  std::vector<float>::const_iterator it = find(collisions.begin(), collisions.end(), lnCollisions);
 
  if (it != collisions.end()) {
    // found the value
    std::vector<float>::difference_type ihi = it - collisions.begin();
    LogTrace(me) << ": using one energy bin " << ihi << " = " << theEnergyBins[ihi]
                 << " for lnCollisions = " << lnCollisions;
    lnE = theEnergyBins[ihi];
  } else {
    // interpolate the value
    std::vector<float>::const_iterator loside =
        find_if(collisions.begin(), collisions.end(), [&lnCollisions](auto c) { return c < lnCollisions; });
    std::vector<float>::difference_type ilo = loside - collisions.begin();
    if (ilo > 0) {
      LogTrace(me) << ": using energy bin " << ilo - 1 << " and " << ilo;
      lnE = theEnergyBins[ilo - 1] + (lnCollisions - collisions[ilo - 1]) *
                                         (theEnergyBins[ilo] - theEnergyBins[ilo - 1]) /
                                         (collisions[ilo] - collisions[ilo - 1]);
    } else {
      LogTrace(me) << ": using one energy bin 0 = " << theEnergyBins[0] << " for lnCollisions = " << lnCollisions;
      lnE = theEnergyBins[0];  //@@ WHAT ELSE TO DO?
    }
  }
 
  return lnE;
}

References c, spr::find(), LogTrace, me, and theEnergyBins.

Referenced by generateEnergyLoss().

readCollisionTable()

void CSCGasCollisions::readCollisionTable ( )

private

Definition at line 92 of file CSCGasCollisions.cc.

                                          {
  // I'd prefer to allow comments in the data file which means
  // complications of reading line-by-line and then item-by-item.
 
  // Is float OK? Or do I need double?
 
  // Do I need any sort of error trapping?
 
  // We use the default CMSSW data file path
  // We use the default file name 'collisions.dat'
 
  // This can be reset in .orcarc by SimpleConfigurable
  //    Muon:Endcap:CollisionsFile
 
  // TODO make configurable
  string colliFile = "SimMuon/CSCDigitizer/data/collisions.dat";
  edm::FileInPath f1{colliFile};
  edm::LogInfo(me) << ": reading " << f1.fullPath();
 
  ifstream fin{f1.fullPath()};
 
  if (fin.fail()) {
    string errorMessage = "Cannot open input file " + f1.fullPath();
    edm::LogError("CSCGasCollisions") << errorMessage;
    throw cms::Exception(errorMessage);
  }
 
  fin.clear();             // Clear eof read status
  fin.seekg(0, ios::beg);  // Position at start of file
 
  // @@ We had better have the right sizes everywhere or all
  // hell will break loose. There's no trapping.
  LogTrace(me) << "Reading gamma bins";
  int j = 0;
  for (int i = 0; i < N_GAMMA; ++i) {
    fin >> theGammaBins[i];
    LogTrace(me) << ++j << "   " << theGammaBins[i];
  }
 
  j = 0;
  LogTrace(me) << "Reading energy bins \n";
  for (int i = 0; i < N_ENERGY; ++i) {
    fin >> theEnergyBins[i];
    LogTrace(me) << ++j << "   " << theEnergyBins[i];
  }
 
  j = 0;
  LogTrace(me) << "Reading collisions table \n";
 
  for (int i = 0; i < N_ENTRIES; ++i) {
    fin >> theCollisionTable[i];
    LogTrace(me) << ++j << "   " << theCollisionTable[i];
  }
 
  fin.close();
}

References Exception, DeadROC_duringRun::f1, groupFilesInBlocks::fin, mps_fire::i, dqmiolumiharvest::j, LogTrace, me, N_ENERGY, N_ENTRIES, N_GAMMA, theCollisionTable, theEnergyBins, and theGammaBins.

Referenced by CSCGasCollisions().

saveGasCollisions()

bool CSCGasCollisions::saveGasCollisions ( void  ) const

inline

Definition at line 40 of file CSCGasCollisions.h.

{ return saveGasCollisions_; }

References saveGasCollisions_.

Referenced by CSCGasCollisions().

setParticleDataTable()

void CSCGasCollisions::setParticleDataTable

(

const ParticleDataTable *

pdt

)

Definition at line 149 of file CSCGasCollisions.cc.

{ theParticleDataTable = pdt; }

References theParticleDataTable.

Referenced by CSCWireHitSim::setParticleDataTable().

simulate()

void CSCGasCollisions::simulate	(	const PSimHit &	simhit,
		std::vector< LocalPoint > &	clusters,
		std::vector< int > &	electrons,
		CLHEP::HepRandomEngine *	engine
	)

Definition at line 151 of file CSCGasCollisions.cc.

                                                              {
  const float epsilonL = 0.01;  // Shortness of simhit 'length'
  //  const float max_gap_z = 1.5;                     // Gas gaps are 0.5
  //  or 1.0 cm
 
  // Note that what I call the 'gap' may in fact be the 'length' of a PSimHit
  // which does not start and end on the gap edges. This confuses the
  // nomenclature at least.
 
  double mom = simhit.pabs();  // in GeV/c - see MuonSensitiveDetector.cc
  //  int iam       = simhit.particleType();           // PDG type
  delete theCrossGap;  // before building new one
  assert(theParticleDataTable != nullptr);
  ParticleData const *particle = theParticleDataTable->particle(simhit.particleType());
  double mass = 0.105658;  // assume a muon
  if (particle == nullptr) {
    edm::LogError("CSCGasCollisions") << "Cannot find particle of type " << simhit.particleType() << " in the PDT";
  } else {
    mass = particle->mass();
  }
 
  theCrossGap = new CSCCrossGap(mass, mom, simhit.exitPoint() - simhit.entryPoint());
  float gapSize = theCrossGap->length();
 
  // Test the simhit 'length' (beware of angular effects)
  //  if ( gapSize <= epsilonL || gapSize > max_gap_z ) {
  if (gapSize <= epsilonL) {
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] WARNING! simhit entry and exit are too close - "
                                        "skipping simhit:"
                                     << "\n entry = " << simhit.entryPoint() << ": exit  = " << simhit.exitPoint()
                                     << "\n particle type = " << simhit.particleType()
                                     << " : momentum = " << simhit.pabs()
                                     << " GeV/c : energy loss = " << simhit.energyLoss() * 1.E06 << " keV"
                                     << ", gapSize = " << gapSize << " cm (< epsilonL = " << epsilonL << " cm)";
    return;  //@@ Just skip this PSimHit
  }
 
  // Interpolate the table for current gamma value
  // Extract collisions binned by energy loss values, for this gamma
  std::vector<float> collisions(N_ENERGY);
  double loggam = theCrossGap->logGamma();
  fillCollisionsForThisGamma(static_cast<float>(loggam), collisions);
 
  double anmin = exp(collisions[N_ENERGY - 1]);
  double anmax = exp(collisions[0]);
  double amu = anmax - anmin;
 
  LogTrace(me) << "collisions extremes = " << collisions[N_ENERGY - 1] << ", " << collisions[0] << "\n"
               << "anmin = " << anmin << ", anmax = " << anmax << "\n"
               << "amu = " << amu << "\n";
 
  float dedx = 0.;        // total energy loss
  double sum_steps = 0.;  // total distance across gap (along simhit direction)
  int n_steps = 0;        // no. of steps/primary collisions
  int n_try = 0;          // no. of tries to generate steps
  double step = -1.;      // Sentinel for start
 
  LocalPoint layerLocalPoint(simhit.entryPoint());
 
  // step/primary collision loop
  while (sum_steps < gapSize) {
    ++n_try;
    if (n_try > MAX_STEPS) {
      int maxst = MAX_STEPS;
      edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] WARNING! n_try = " << n_try
                                       << " is > MAX_STEPS = " << maxst << " - skipping simhit:"
                                       << "\n entry = " << simhit.entryPoint() << ": exit  = " << simhit.exitPoint()
                                       << "\n particle type = " << simhit.particleType()
                                       << " : momentum = " << simhit.pabs()
                                       << " GeV/c : energy loss = " << simhit.energyLoss() * 1.E06 << " keV"
                                       << "\n gapSize = " << gapSize << " cm, last step = " << step
                                       << " cm, sum_steps = " << sum_steps << " cm, n_steps = " << n_steps;
      break;
    }
    step = generateStep(amu, engine);
    if (sum_steps + step > gapSize)
      break;  // this step goes too far
 
    float eloss = generateEnergyLoss(amu, anmin, anmax, collisions, engine);
 
    // Is the eloss too large? (then GEANT should have produced hits!)
    if (eloss > deCut) {
      edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] WARNING! eloss = " << eloss << " eV is too large (> "
                                       << deCut << " eV) - trying another collision";
      continue;  // to generate another collision/step
    }
 
    dedx += eloss;      // the energy lost from the ionizing particle
    sum_steps += step;  // the position of the ionizing particle
    ++n_steps;          // the number of primary collisions
 
    if (n_steps > MAX_STEPS) {  // Extra-careful trap for bizarreness
      edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] WARNING! " << n_steps
                                       << " is too many steps -  skipping simhit:"
                                       << "\n entry = " << simhit.entryPoint() << ": exit  = " << simhit.exitPoint()
                                       << "\n particle type = " << simhit.particleType()
                                       << " : momentum = " << simhit.pabs()
                                       << " GeV/c : energy loss = " << simhit.energyLoss() * 1.E06 << " keV"
                                       << "\ngapSize=" << gapSize << " cm, last step=" << step
                                       << " cm, sum_steps=" << sum_steps << " cm";
      break;
    }
    LogTrace(me) << "sum_steps = " << sum_steps << " cm , dedx = " << dedx << " eV";
 
    // Generate ionization.
    // eion is the minimum energy at which ionization can occur in the gas
    if (eloss > eion) {
      layerLocalPoint += step * theCrossGap->unitVector();  // local point where the collision occurs
      ionize(eloss, layerLocalPoint);
    } else {
      LogTrace(me) << "Energy available = " << eloss << " eV is too low for ionization (< eion = " << eion << " eV)";
    }
 
  }  // step/collision loop
 
  if (dumpGasCollisions())
    writeSummary(n_try, n_steps, sum_steps, dedx, simhit);
 
  // Return values in two container arguments
  positions = theCrossGap->ionClusters();
  electrons = theCrossGap->electrons();
  return;
}

References cms::cuda::assert(), deCut, dumpGasCollisions(), eion, pwdgSkimBPark_cfi::electrons, CSCCrossGap::electrons(), PSimHit::energyLoss(), PSimHit::entryPoint(), PSimHit::exitPoint(), JetChargeProducer_cfi::exp, fillCollisionsForThisGamma(), generateEnergyLoss(), generateStep(), CSCCrossGap::ionClusters(), ionize(), CSCCrossGap::length(), CSCCrossGap::logGamma(), LogTrace, EgHLTOffHistBins_cfi::mass, MAX_STEPS, me, N_ENERGY, PSimHit::pabs(), PSimHit::particleType(), theCrossGap, theParticleDataTable, CSCCrossGap::unitVector(), and writeSummary().

Referenced by CSCWireHitSim::getIonizationClusters().

writeSummary()

void CSCGasCollisions::writeSummary ( int  n_try, int  n_steps, double  sum_steps, float  dedx, const PSimHit &  simhit  ) const

private

Definition at line 398 of file CSCGasCollisions.cc.

                                                                                                                     {
  // Switched from std::cout to LogVerbatim, Mar 2015
 
  std::vector<LocalPoint> ion_clusters = theCrossGap->ionClusters();
  std::vector<int> electrons = theCrossGap->electrons();
  std::vector<float> elosses = theCrossGap->eLossPerStep();
  std::vector<double> steps = theCrossGap->stepLengths();
 
  edm::LogVerbatim("CSCDigitizer") << "------------------"
                                   << "\nAFTER CROSSING GAP";
  /*
  edm::LogVerbatim("CSCDigitizer") << "no. of steps tried             = " <<
  n_try
                                 << "\nno. of steps from theCrossGap  = " <<
  theCrossGap->noOfSteps()
                                 << "\nsize of steps vector           = " <<
  steps.size();
 
  edm::LogVerbatim("CSCDigitizer") << "no. of collisions (steps)      = " <<
  n_steps
                                 << "\nsize of elosses vector         = " <<
  elosses.size()
                                 << "\nsize of ion clusters vector    = " <<
  ion_clusters.size()
                                 << "\nsize of electrons vector       = " <<
  electrons.size();
  */
 
  size_t nsteps = n_steps;          // force ridiculous type conversion
  size_t mstep = steps.size() - 1;  // final step gets filled but is outside gas
                                    // gap - unless we reach MAX_STEPS
  if ((nsteps != MAX_STEPS) && (nsteps != mstep)) {
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] WARNING! no. of steps = " << nsteps
                                     << " .ne. steps.size()-1 = " << mstep;
  }
  size_t meloss = elosses.size();
 
  if (nsteps != meloss) {
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] WARNING! no. of steps = " << nsteps
                                     << " .ne. no. of elosses = " << meloss;
  } else {
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] # / length of step / energy loss per collision:";
    for (size_t i = 0; i != nsteps; ++i) {
      edm::LogVerbatim("CSCDigitizer") << i + 1 << " / S: " << steps[i] << " / E: " << elosses[i];
    }
  }
 
  size_t mclus = ion_clusters.size();
  size_t melec = electrons.size();
 
  if (mclus != melec) {
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] WARNING! size of cluster vector = " << mclus
                                     << " .ne. size of electrons vector = " << melec;
  } else {
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] # / postion of "
                                        "cluster / electrons per cluster: ";
    for (size_t i = 0; i != mclus; ++i) {
      edm::LogVerbatim("CSCDigitizer") << i + 1 << " / I: " << ion_clusters[i] << " / E: " << electrons[i];
    }
  }
 
  int n_ic = count_if(elosses.begin(), elosses.end(), [&](auto c) { return c > this->eion; });
 
  edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] total no. of collision steps = " << n_steps;
  edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] total sum of steps = " << sum_steps << " cm";
  if (nsteps > 0)
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] average step length = " << sum_steps / float(nsteps)
                                     << " cm";
  edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] total energy loss across gap = " << dedx
                                   << " eV = " << dedx / 1000. << " keV";
  edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] no. of primary ionizing collisions across gap = "
                                      "no. with eloss > eion = "
                                   << eion << " eV = " << n_ic;
  if (nsteps > 0)
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] average energy loss/collision = " << dedx / float(nsteps)
                                     << " eV";
 
  std::vector<int>::const_iterator bigger = find(electrons.begin(), electrons.end(), 0);
  if (bigger != electrons.end()) {
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] TROUBLE! There is a cluster with 0 electrons.";
  }
 
  int n_e = accumulate(electrons.begin(), electrons.end(), 0);
 
  edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] SUMMARY: simhit"
                                   << "\n entry = " << simhit.entryPoint() << ": exit  = " << simhit.exitPoint()
                                   << "\n particle type = " << simhit.particleType()
                                   << " : momentum = " << simhit.pabs()
                                   << " GeV/c : energy loss = " << simhit.energyLoss() * 1.E06 << " keV";
 
  if (nsteps > 0) {
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisions] SUMMARY: ionization"
                                     << " : steps= " << nsteps << " : sum(steps)= " << sum_steps
                                     << " cm : <step>= " << sum_steps / float(nsteps) << " cm"
                                     << " : ionizing= " << n_ic << " : ionclus= " << mclus << " : total e= " << n_e
                                     << " : <dedx/step>= " << dedx / float(nsteps)
                                     << " eV : <e/ionclus>= " << float(n_e) / float(mclus)
                                     << " : dedx= " << dedx / 1000. << " keV";
  } else {
    edm::LogVerbatim("CSCDigitizer") << "[CSCGasCollisons] ERROR? no collision steps!";
  }
 
  // Turn off output file -  used for initial development
  //  if ( saveGasCollisions() ) {
  //    ofstream of0("osteplen.dat",ios::app);
  //    std::copy( steps.begin(), steps.end(),
  //    std::ostream_iterator<float>(of0,"\n"));
 
  //    ofstream of1("olperc.dat",ios::app);
  //    std::copy( elosses.begin(), elosses.end(),
  //    std::ostream_iterator<float>(of1,"\n"));
 
  //   ofstream of2("oclpos.dat",ios::app);
  //   std::copy( ion_clusters.begin(), ion_clusters.end(),
  //   std::ostream_iterator<LocalPoint>(of2,"\n"));
 
  //   ofstream of3("oepercl.dat",ios::app);
  //   std::copy( electrons.begin(), electrons.end(),
  //   std::ostream_iterator<int>(of3,"\n"));
  // }
}

References c, eion, pwdgSkimBPark_cfi::electrons, CSCCrossGap::electrons(), CSCCrossGap::eLossPerStep(), PSimHit::energyLoss(), PSimHit::entryPoint(), PSimHit::exitPoint(), spr::find(), dqmMemoryStats::float, mps_fire::i, CSCCrossGap::ionClusters(), MAX_STEPS, PSimHit::pabs(), PSimHit::particleType(), CSCCrossGap::stepLengths(), customisers::steps, and theCrossGap.

Referenced by simulate().

Member Data Documentation

clusterExtent

double CSCGasCollisions::clusterExtent

private

Definition at line 72 of file CSCGasCollisions.h.

Referenced by CSCGasCollisions(), and ionize().

deCut

double CSCGasCollisions::deCut

private

Definition at line 69 of file CSCGasCollisions.h.

Referenced by CSCGasCollisions(), and simulate().

dumpGasCollisions_

bool CSCGasCollisions::dumpGasCollisions_

private

Definition at line 83 of file CSCGasCollisions.h.

Referenced by CSCGasCollisions(), and dumpGasCollisions().

eion

double CSCGasCollisions::eion

private

Definition at line 70 of file CSCGasCollisions.h.

Referenced by CSCGasCollisions(), ionize(), simulate(), and writeSummary().

ework

double CSCGasCollisions::ework

private

Definition at line 71 of file CSCGasCollisions.h.

Referenced by CSCGasCollisions(), and ionize().

gasDensity

double CSCGasCollisions::gasDensity

private

Definition at line 63 of file CSCGasCollisions.h.

Referenced by CSCGasCollisions(), and ionize().

MAX_STEPS

const int CSCGasCollisions::MAX_STEPS = 400

static

Definition at line 45 of file CSCGasCollisions.h.

Referenced by simulate(), and writeSummary().

me

const std::string CSCGasCollisions::me

private

Definition at line 62 of file CSCGasCollisions.h.

Referenced by CSCGasCollisions(), fillCollisionsForThisGamma(), generateEnergyLoss(), generateStep(), ionize(), lnEnergyLoss(), readCollisionTable(), simulate(), and ~CSCGasCollisions().

N_ENERGY

const int CSCGasCollisions::N_ENERGY = 63

static

Definition at line 43 of file CSCGasCollisions.h.

Referenced by fillCollisionsForThisGamma(), readCollisionTable(), and simulate().

N_ENTRIES

const int CSCGasCollisions::N_ENTRIES = N_GAMMA * N_ENERGY

static

Definition at line 44 of file CSCGasCollisions.h.

Referenced by readCollisionTable().

N_GAMMA

const int CSCGasCollisions::N_GAMMA = 21

static

Definition at line 42 of file CSCGasCollisions.h.

Referenced by fillCollisionsForThisGamma(), and readCollisionTable().

saveGasCollisions_

bool CSCGasCollisions::saveGasCollisions_

private

Definition at line 81 of file CSCGasCollisions.h.

Referenced by saveGasCollisions().

theCollisionTable

std::vector<float> CSCGasCollisions::theCollisionTable

private

Definition at line 77 of file CSCGasCollisions.h.

Referenced by fillCollisionsForThisGamma(), and readCollisionTable().

theCrossGap

CSCCrossGap* CSCGasCollisions::theCrossGap

private

Definition at line 79 of file CSCGasCollisions.h.

Referenced by generateEnergyLoss(), generateStep(), ionize(), simulate(), writeSummary(), and ~CSCGasCollisions().

theEnergyBins

std::vector<float> CSCGasCollisions::theEnergyBins

private

Definition at line 76 of file CSCGasCollisions.h.

Referenced by lnEnergyLoss(), and readCollisionTable().

theGammaBins

std::vector<float> CSCGasCollisions::theGammaBins

private

Definition at line 75 of file CSCGasCollisions.h.

Referenced by fillCollisionsForThisGamma(), and readCollisionTable().

theParticleDataTable

const ParticleDataTable* CSCGasCollisions::theParticleDataTable

private

Definition at line 80 of file CSCGasCollisions.h.

Referenced by setParticleDataTable(), and simulate().