phot::ScintTimeLAr Class Reference

#include "ScintTimeLAr.h"

Inheritance diagram for phot::ScintTimeLAr:

Public Member Functions
	ScintTimeLAr (fhicl::ParameterSet const &pset)
void	initRand (CLHEP::HepRandomEngine &engine)
void	GenScintTime (bool is_fast, CLHEP::HepRandomEngine &engine)
double	fastScintTime ()
double	slowScintTime ()
double	GetScintTime () const

Protected Attributes
double	timing {0.0}

Private Member Functions
double	single_exp (double t, double tau2) const
double	bi_exp (double t, double tau1, double tau2) const
double	with_rising_time (double tau1, double tau2)

Private Attributes
int	LogLevel
std::unique_ptr< CLHEP::RandFlat >	fUniformGen
const double	SRTime
const double	SDTime
const double	FRTime
const double	FDTime
const bool	fNoFastRisingTime
const bool	fNoSlowRisingTime

Detailed Description

Definition at line 24 of file ScintTimeLAr.h.

Constructor & Destructor Documentation

phot::ScintTimeLAr::ScintTimeLAr ( fhicl::ParameterSet const &  pset )

explicit

Definition at line 15 of file ScintTimeLAr.cc.

References e, FDTime, fNoFastRisingTime, fNoSlowRisingTime, FRTime, fhicl::ParameterSet::get(), LogLevel, SDTime, and SRTime.

    : LogLevel{pset.get<int>("LogLevel")}
    , SRTime{pset.get<double>("SlowRisingTime", 0.)}
    , SDTime{pset.get<double>("SlowDecayTime", 0.)}
    , FRTime{pset.get<double>("FastRisingTime", 0.)}
    , FDTime{pset.get<double>("FastDecayTime", 0.)}
    , fNoFastRisingTime((FRTime >= 1.e-8) && (FRTime != -1.))
    , fNoSlowRisingTime((SRTime >= 1.e-8) && (SRTime != -1.))
  {
    if (LogLevel >= 1) {
      std::cout << "ScintTimeLAr Tool configure:" << std::endl;
      std::cout << "Fast rising time: " << FRTime << ", Fast decay time: " << FDTime
                << ", Slow rising time: " << SRTime << ", Slow decay time: " << SDTime << std::endl;
    }
  }

Member Function Documentation

double phot::ScintTimeLAr::bi_exp ( double  t, double  tau1, double  tau2  ) const

private

Definition at line 43 of file ScintTimeLAr.cc.

Referenced by GenScintTime(), and with_rising_time().

  {
    return (((std::exp((-1.0 * t) / tau2) * (1.0 - std::exp((-1.0 * t) / tau1))) / tau2) / tau2) *
           (tau1 + tau2);
  }

double phot::ScintTimeLAr::fastScintTime ( )

inlinevirtual

Implements phot::ScintTime.

Definition at line 106 of file ScintTimeLAr.cc.

References FDTime, fNoFastRisingTime, FRTime, fUniformGen, and with_rising_time().

  {
    if (fNoFastRisingTime) { return -FDTime * std::log(fUniformGen->fire()); }
    return with_rising_time(FRTime, FDTime);
  }

void phot::ScintTimeLAr::GenScintTime ( bool  is_fast, CLHEP::HepRandomEngine &  engine  )

virtual

Implements phot::ScintTime.

Definition at line 71 of file ScintTimeLAr.cc.

References bi_exp(), d, e, FDTime, FRTime, SDTime, single_exp(), SRTime, and phot::ScintTime::timing.

  {
    double tau1;
    double tau2;

    if (is_fast) {
      tau1 = FRTime;
      tau2 = FDTime;
    }
    else {
      tau1 = SRTime;
      tau2 = SDTime;
    }

    CLHEP::RandFlat randflatscinttime{engine};

    if ((tau1 < 1e-8) || (tau1 == -1.0)) {
      timing = -tau2 * std::log(randflatscinttime());
      return;
    }

    //ran1, ran2 = random numbers for the algorithm
    while (1) {
      auto ran1 = randflatscinttime();
      auto ran2 = randflatscinttime();
      auto d = (tau1 + tau2) / tau2;
      auto t = -tau2 * std::log(1 - ran1);
      auto g = d * single_exp(t, tau2);
      if (ran2 <= bi_exp(t, tau1, tau2) / g) {
        timing = t;
        return;
      }
    }
  }

double phot::ScintTime::GetScintTime ( ) const

inlineinherited

Definition at line 22 of file ScintTime.h.

{ return timing; }

void phot::ScintTimeLAr::initRand ( CLHEP::HepRandomEngine &  engine )

virtual

Implements phot::ScintTime.

Definition at line 31 of file ScintTimeLAr.cc.

References fUniformGen.

  {
    fUniformGen = std::make_unique<CLHEP::RandFlat>(engine);
  }

double phot::ScintTimeLAr::single_exp ( double  t, double  tau2  ) const

private

Definition at line 37 of file ScintTimeLAr.cc.

Referenced by GenScintTime(), and with_rising_time().

  {
    return std::exp((-1.0 * t) / tau2) / tau2;
  }

double phot::ScintTimeLAr::slowScintTime ( )

inlinevirtual

Implements phot::ScintTime.

Definition at line 112 of file ScintTimeLAr.cc.

References fNoSlowRisingTime, fUniformGen, SDTime, SRTime, and with_rising_time().

  {
    if (fNoSlowRisingTime) { return -SDTime * std::log(fUniformGen->fire()); }
    return with_rising_time(SRTime, SDTime);
  }

double phot::ScintTimeLAr::with_rising_time ( double  tau1, double  tau2  )

private

Definition at line 50 of file ScintTimeLAr.cc.

References bi_exp(), d, fUniformGen, and single_exp().

Referenced by fastScintTime(), and slowScintTime().

  {
    // TODO: This method is very inefficient.
    // If we care about simulating the rising time, it would be better
    // to simulate random numbers according a general distribution
    double d = (tau1 + tau2) / tau2;
    while (1) {
      double ran1 = fUniformGen->fire();
      double ran2 = fUniformGen->fire();
      double t = -tau2 * std::log(1 - ran1);
      double g = d * single_exp(t, tau2);
      if (ran2 <= bi_exp(t, tau1, tau2) / g) { return t; }
    }
  }

Member Data Documentation

const double phot::ScintTimeLAr::FDTime

private

Definition at line 39 of file ScintTimeLAr.h.

Referenced by fastScintTime(), GenScintTime(), and ScintTimeLAr().

const bool phot::ScintTimeLAr::fNoFastRisingTime

private

Definition at line 40 of file ScintTimeLAr.h.

Referenced by fastScintTime(), and ScintTimeLAr().

const bool phot::ScintTimeLAr::fNoSlowRisingTime

private

Definition at line 40 of file ScintTimeLAr.h.

Referenced by ScintTimeLAr(), and slowScintTime().

const double phot::ScintTimeLAr::FRTime

private

Definition at line 38 of file ScintTimeLAr.h.

Referenced by fastScintTime(), GenScintTime(), and ScintTimeLAr().

std::unique_ptr<CLHEP::RandFlat> phot::ScintTimeLAr::fUniformGen

private

Definition at line 34 of file ScintTimeLAr.h.

Referenced by fastScintTime(), initRand(), slowScintTime(), and with_rising_time().

int phot::ScintTimeLAr::LogLevel

private

Definition at line 33 of file ScintTimeLAr.h.

Referenced by ScintTimeLAr().

const double phot::ScintTimeLAr::SDTime

private

Definition at line 37 of file ScintTimeLAr.h.

Referenced by GenScintTime(), ScintTimeLAr(), and slowScintTime().

const double phot::ScintTimeLAr::SRTime

private

Definition at line 36 of file ScintTimeLAr.h.

Referenced by GenScintTime(), ScintTimeLAr(), and slowScintTime().

double phot::ScintTime::timing {0.0}

protectedinherited

Definition at line 29 of file ScintTime.h.

Referenced by GenScintTime().

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

• larsim/v09_43_00/source/larsim/PhotonPropagation/ScintTimeTools/ScintTimeLAr.h
• larsim/v09_43_00/source/larsim/PhotonPropagation/ScintTimeTools/ScintTimeLAr.cc