JDETECTOR::JK40DefaultSimulator Class Reference

Default implementation of the simulation of K40 background. More...

#include <JK40DefaultSimulator.hh>

Inheritance diagram for JDETECTOR::JK40DefaultSimulator:

Public Member Functions
	JK40DefaultSimulator ()
	Default constructor. More...
	JK40DefaultSimulator (const JK40Rates &rates)
	Constructor. More...
virtual double	getSinglesRate (const JPMTIdentifier &pmt) const
	Get singles rate as a function of PMT. More...
virtual double	getMultiplesRate (const JModuleIdentifier &module, const int M) const
	Get multiples rate as a function of optical module. More...
virtual double	getProbability (const double ct) const
	Get probability of coincidence. More...
virtual void	generateHits (const JModule &module, const JTimeRange &period, JModuleData &output) const
	Generate hits. More...
double	getSinglesRate () const
	Get singles rate. More...
double	getMultiplesRate (const multiplicity_type M) const
	Get multiples rate. More...
multiplicity_type	getLowerL1Multiplicity () const
	Get lower multiplicty. More...
multiplicity_type	getUpperL1Multiplicity () const
	Get upper multiplicty. More...
void	correct (const double QE)
	Correct rates for global efficiency,. More...

Static Public Member Functions
static JK40DefaultSimulator &	getInstance ()
	Get reference to unique instance of this class object. More...
static unsigned int	getRandomIndex (const JBuffer1D_t &buffer, const double random)
	Get index based on random value. More...
static double	getSigma ()
	Get intrinsic time smearing of K40 coincidences. More...

Static Public Attributes
static const multiplicity_type	LOWER_L1_MULTIPLICITY = 2
	Lower L1 multiplicity. More...

Static Protected Member Functions
static double	p1 ()
	Parameters for probability of coincidence as a function of the cosine of space angle between PMT axes. More...
static double	p2 ()
static double	p3 ()
static double	p4 ()

Protected Attributes
JRateL0_t	rateL0
	singles rate [Hz] More...
JRateL1_t	rateL1
	multiples rates [Hz] More...

Private Attributes
JBuffer2D_t	probability2D
	This correlation matrix is a two-dimensional array in which element [i][j] corresponds to the probability of a genuine coincidence due to K40 decays, where i and j refer to the indices of the PMTs in the optical module. More...
JBuffer1D_t	probability1D
	This probability vector is a one-dimensional array in which element [i] corresponds to the probability of a genuine coincidence due to K40 decays, where i refers to the index of the PMT in the optical module. More...
JBuffer1D_t	probabilityND
	This probability vector is a one-dimensional array in which element [i] corresponds to the probability of an additional hit, where i refers to the index of the PMT in the optical module. More...
JBuffer1D_t	rateL1_Hz
	Multiples rate as a function of the multiplicity. More...

Friends
std::istream &	operator>> (std::istream &in, JK40DefaultSimulator &object)
	Read K40 simulator from input. More...
std::ostream &	operator<< (std::ostream &out, const JK40DefaultSimulator &object)
	Write K40 simulator to output. More...

Detailed Description

Default implementation of the simulation of K40 background.

This class implements the JK40Simulator interface.

Definition at line 25 of file JK40DefaultSimulator.hh.

Constructor & Destructor Documentation

JK40DefaultSimulator() [1/2]

JDETECTOR::JK40DefaultSimulator::JK40DefaultSimulator ( )

inline

Default constructor.

Definition at line 33 of file JK40DefaultSimulator.hh.

                           :
      JK40Rates()
    {}

JK40DefaultSimulator() [2/2]

JDETECTOR::JK40DefaultSimulator::JK40DefaultSimulator ( const JK40Rates &  rates )

inline

Constructor.

Parameters

rates

K40 rates [Hz]

Definition at line 43 of file JK40DefaultSimulator.hh.

                                                 :
      JK40Rates(rates)
    {}

Member Function Documentation

getInstance()

static JK40DefaultSimulator& JDETECTOR::JK40DefaultSimulator::getInstance ( )

inlinestatic

Get reference to unique instance of this class object.

This method returns an object with default values. The singles and multiples rates are taken from KM3NeT internal note "Detector simulations for KM3NeT".

Returns

reference to this class object

Definition at line 57 of file JK40DefaultSimulator.hh.

    {
      static JK40DefaultSimulator k40Simulator(JK40Rates::getInstance());
 
      return k40Simulator;
    }

getSinglesRate() [1/2]

virtual double JDETECTOR::JK40DefaultSimulator::getSinglesRate ( const JPMTIdentifier &  pmt ) const

inlinevirtual

Get singles rate as a function of PMT.

Parameters

pmt	PMT identifier

Returns

rate [Hz]

Implements JDETECTOR::JK40DefaultSimulatorInterface.

Reimplemented in JDETECTOR::JK40RunByRunSimulator.

Definition at line 71 of file JK40DefaultSimulator.hh.

    {
      return JK40Rates::getSinglesRate();
    }

getMultiplesRate() [1/2]

virtual double JDETECTOR::JK40DefaultSimulator::getMultiplesRate ( const JModuleIdentifier &  module, const int  M  ) const

inlinevirtual

Get multiples rate as a function of optical module.

Parameters

module	optical module identifier
M	multiplicity (M >= 2)

Returns

rate [Hz]

Implements JDETECTOR::JK40DefaultSimulatorInterface.

Definition at line 84 of file JK40DefaultSimulator.hh.

    {
      return JK40Rates::getMultiplesRate(M);
    }

getProbability()

virtual double JDETECTOR::JK40DefaultSimulator::getProbability ( const double  ct ) const

inlinevirtual

Get probability of coincidence.

Parameters

ct	cosine space angle between PMT axes

Returns

probability

Implements JDETECTOR::JK40DefaultSimulatorInterface.

Definition at line 96 of file JK40DefaultSimulator.hh.

    {
      return exp(ct * (p1() + ct * (p2() + ct * (p3() + ct*p4()))));
    }

p1()

static double JDETECTOR::JK40DefaultSimulator::p1 ( )

inlinestaticprotected

Parameters for probability of coincidence as a function of the cosine of space angle between PMT axes.

Values are provided by V.Kulikovski.

Definition at line 155 of file JK40DefaultSimulator.hh.

{ return  2.85261; }

p2()

static double JDETECTOR::JK40DefaultSimulator::p2 ( )

inlinestaticprotected

Definition at line 156 of file JK40DefaultSimulator.hh.

{ return -0.949097; }

p3()

static double JDETECTOR::JK40DefaultSimulator::p3 ( )

inlinestaticprotected

Definition at line 157 of file JK40DefaultSimulator.hh.

{ return  0.182419; }

p4()

static double JDETECTOR::JK40DefaultSimulator::p4 ( )

inlinestaticprotected

Definition at line 158 of file JK40DefaultSimulator.hh.

{ return  1.23075; }

generateHits()

virtual void JDETECTOR::JK40DefaultSimulatorInterface::generateHits ( const JModule &  module, const JTimeRange &  period, JModuleData &  output  ) const

inlinevirtualinherited

Generate hits.

Parameters

module	module
period	time window [ns]
output	background data

Implements JDETECTOR::JK40Simulator.

Definition at line 112 of file JK40DefaultSimulatorInterface.hh.

    {
 
      // resize internal buffers
      
      const int N = module.size();
 
      probability2D.resize(N);
      probability1D.resize(N);
      probabilityND.resize(N);
 
      rateL1_Hz.resize(N);
 
 
      // generate singles
 
      for (int pmt = 0; pmt != N; ++pmt) {
 
        const double rateL0_Hz = getSinglesRate(JPMTIdentifier(module.getID(), pmt));
 
        if (rateL0_Hz > 0.0) {
              
          const double t_ns = 1.0e9 / rateL0_Hz;          // [ns]
              
          for (double t1 = period.getLowerLimit() + gRandom->Exp(t_ns); t1 < period.getUpperLimit(); t1 += gRandom->Exp(t_ns)) {
            output[pmt].push_back(JPMTSignal(t1, 1));
          }
        }
      }
 
 
      // generate coincidences
 
      double totalRateL1_Hz = 0.0;
 
      for (int i = 0; i != N; ++i) {
        totalRateL1_Hz += rateL1_Hz[i] = getMultiplesRate(module.getID(), i + 2);
      }
 
      if (totalRateL1_Hz > 0.0) {
 
        const double t_ns = 1.0e9 / totalRateL1_Hz;       // [ns]
 
        double t1 = period.getLowerLimit() + gRandom->Exp(t_ns);
 
        if (t1 < period.getUpperLimit()) {
 
 
          // configure correlation matrix
 
          for (int i = 0; i != N; ++i) {
            
            probability2D[i][i] = 0.0;
 
            for (int j = i + 1; j != N; ++j) {
              
              const double ct = JMATH::getDot(module[i], module[j]);
              const double p  = getProbability(ct);
              
              probability2D[i][j] = p;
              probability2D[j][i] = p;
            }
          }
 
 
          // determine probability of a coincidence as a function of the PMT number
          
          for (int i = 0; i != N; ++i) {
 
            probability1D[i] = 0.0;
 
            for (int j = 0; j != N; ++j) {
              probability1D[i] += probability2D[i][j];
            }
          }
 
 
          for ( ; t1 < period.getUpperLimit(); t1 += gRandom->Exp(t_ns)) {
 
 
            // generate two-fold coincidence
 
            const unsigned int pmt1 = getRandomIndex(probability1D,       gRandom->Rndm());
            const unsigned int pmt2 = getRandomIndex(probability2D[pmt1], gRandom->Rndm());
 
            output[pmt1].insert(JPMTSignal(gRandom->Gaus(t1, getSigma()), 1));
            output[pmt2].insert(JPMTSignal(gRandom->Gaus(t1, getSigma()), 1));
 
 
            try {
 
              // generate larger than two-fold coincidences, if any
 
              unsigned int M = getRandomIndex(rateL1_Hz, gRandom->Rndm());
 
              if (M != 0) {
 
                probabilityND = probability2D[pmt1];
 
                for (unsigned int pmtN = pmt2; M != 0; --M) {
 
                  for (int i = 0; i != N; ++i) {
                    probabilityND[i] *= probability2D[pmtN][i];
                  }
 
                  probabilityND[pmtN] = 0.0;
                  
                  pmtN = getRandomIndex(probabilityND, gRandom->Rndm());
                  
                  output[pmtN].insert(JPMTSignal(gRandom->Gaus(t1, getSigma()), 1));
                }
              }
            }
            catch (const JNumericalPrecision&) {}
          }
        }
      }
    }

getRandomIndex()

static unsigned int JDETECTOR::JK40DefaultSimulatorInterface::getRandomIndex ( const JBuffer1D_t &  buffer, const double  random  )

inlinestaticinherited

Get index based on random value.

It is assumed that the values of the input buffer monotonously decrease or increase. This method throws an exception when the summed values in the input buffer is zero.

Parameters

buffer	input values
random	random value <0,1]

Returns

index

Definition at line 244 of file JK40DefaultSimulatorInterface.hh.

    {
      double x = 0.0;
 
      for (JBuffer1D_t::const_iterator i = buffer.begin(); i != buffer.end(); ++i) {
        x += *i;
      }
 
      if (x > 0.0) {
 
        x *= random;
 
        unsigned int index = 0;
 
        for (JBuffer1D_t::const_iterator i = buffer.begin(); i != buffer.end() && (x -= *i) > 0.0; ++i, ++index) {}
 
        if (index == buffer.size()) {
          --index;
        }
 
        return index;
 
      } else {
 
        THROW(JNumericalPrecision, "getRandomIndex(): zero or negative probability.");
      }
    }

getSigma()

static double JDETECTOR::JK40DefaultSimulatorInterface::getSigma ( )

inlinestaticinherited

Get intrinsic time smearing of K40 coincidences.

Returns

sigma [ns]

Definition at line 278 of file JK40DefaultSimulatorInterface.hh.

    {
      return 0.5;
    }

getSinglesRate() [2/2]

double JDETECTOR::JK40Rates::getSinglesRate ( ) const

inlineinherited

Get singles rate.

Returns

rate [Hz]

Definition at line 97 of file JK40Rates.hh.

    {
      return rateL0;
    }

getMultiplesRate() [2/2]

double JDETECTOR::JK40Rates::getMultiplesRate ( const multiplicity_type  M ) const

inlineinherited

Get multiples rate.

Parameters

M	multiplicity (M >= JK40Rates::LOWER_L1_MULTIPLICITY)

Returns

rate [Hz]

Definition at line 109 of file JK40Rates.hh.

    {
      if (M >= LOWER_L1_MULTIPLICITY && M - LOWER_L1_MULTIPLICITY < (multiplicity_type) rateL1.size())
        return rateL1[M - LOWER_L1_MULTIPLICITY];
      else
        return 0.0;
    }

getLowerL1Multiplicity()

multiplicity_type JDETECTOR::JK40Rates::getLowerL1Multiplicity ( ) const

inlineinherited

Get lower multiplicty.

Returns

lower multiplicity

Definition at line 123 of file JK40Rates.hh.

    {
      return LOWER_L1_MULTIPLICITY;
    }

getUpperL1Multiplicity()

multiplicity_type JDETECTOR::JK40Rates::getUpperL1Multiplicity ( ) const

inlineinherited

Get upper multiplicty.

Returns

upper multiplicity

Definition at line 134 of file JK40Rates.hh.

    {
      return rateL1.size() + 1;
    }

correct()

void JDETECTOR::JK40Rates::correct ( const double  QE )

inlineinherited

Correct rates for global efficiency,.

Parameters

QE	global efficiency

Definition at line 145 of file JK40Rates.hh.

    {
      if (QE > 0.0) {
      
        rateL0 /= QE;
 
        JRateL1_t buffer = rateL1;
        
        for (multiplicity_type M = getUpperL1Multiplicity(); M >= getLowerL1Multiplicity(); --M) {
 
          // determine contribution from higher multiplicities
          
          double R = 0.0;
          
          for (multiplicity_type i = M + 1; i <= getUpperL1Multiplicity(); ++i) {
            R += buffer[i - LOWER_L1_MULTIPLICITY] * TMath::Binomial(i, M) * pow(QE, M) * pow(1.0 - QE, i - M);
          }
 
          if (getMultiplesRate(M) > R)
            buffer[M - LOWER_L1_MULTIPLICITY] = (getMultiplesRate(M) - R) / pow(QE, M);
          else
            buffer[M - LOWER_L1_MULTIPLICITY] =  0.0;
        }
 
        rateL1 = buffer;
        
      } else {
 
        rateL0 = 0.0;
 
        for (JRateL1_t::iterator i = rateL1.begin(); i != rateL1.end(); ++i) {
          *i = 0.0;
        }
      }
    }

Friends And Related Function Documentation

operator>>

std::istream& operator>> ( std::istream &  in, JK40DefaultSimulator &  object  )

friend

Read K40 simulator from input.

Parameters

in	input stream
object	K40 simulator

Returns

input stream

Definition at line 109 of file JK40DefaultSimulator.hh.

    {
      const double rateL0 = object.rateL0;
 
      if (in >> object.rateL0) {
 
        object.rateL1.clear();
 
        for (double x; in >> x; ) {
          object.rateL1.push_back(x);
        }
 
      } else {
 
        object.rateL0 = rateL0;
      }
 
      return in;
    }

operator<<

std::ostream& operator<< ( std::ostream &  out, const JK40DefaultSimulator &  object  )

friend

Write K40 simulator to output.

Parameters

out	output stream
object	K40 simulator

Returns

output stream

Definition at line 137 of file JK40DefaultSimulator.hh.

    {
      out << object.rateL0;
 
      for (JRateL1_t::const_iterator i = object.rateL1.begin(); i != object.rateL1.end(); ++i) {
        out << ' ' << *i;
      }
 
      return out;
    }

Member Data Documentation

probability2D

JBuffer2D_t JDETECTOR::JK40DefaultSimulatorInterface::probability2D

mutableprivateinherited

This correlation matrix is a two-dimensional array in which element [i][j] corresponds to the probability of a genuine coincidence due to K40 decays, where i and j refer to the indices of the PMTs in the optical module.

Definition at line 289 of file JK40DefaultSimulatorInterface.hh.

probability1D

JBuffer1D_t JDETECTOR::JK40DefaultSimulatorInterface::probability1D

mutableprivateinherited

This probability vector is a one-dimensional array in which element [i] corresponds to the probability of a genuine coincidence due to K40 decays, where i refers to the index of the PMT in the optical module.

Definition at line 296 of file JK40DefaultSimulatorInterface.hh.

probabilityND

JBuffer1D_t JDETECTOR::JK40DefaultSimulatorInterface::probabilityND

mutableprivateinherited

This probability vector is a one-dimensional array in which element [i] corresponds to the probability of an additional hit, where i refers to the index of the PMT in the optical module.

Definition at line 303 of file JK40DefaultSimulatorInterface.hh.

rateL1_Hz

JBuffer1D_t JDETECTOR::JK40DefaultSimulatorInterface::rateL1_Hz

mutableprivateinherited

Multiples rate as a function of the multiplicity.

The index i corresponds to multiplicity M = i + 2.

Definition at line 309 of file JK40DefaultSimulatorInterface.hh.

LOWER_L1_MULTIPLICITY

const multiplicity_type JDETECTOR::JK40Rates::LOWER_L1_MULTIPLICITY = 2

staticinherited

Lower L1 multiplicity.

Definition at line 232 of file JK40Rates.hh.

rateL0

JRateL0_t JDETECTOR::JK40Rates::rateL0

protectedinherited

singles rate [Hz]

Definition at line 236 of file JK40Rates.hh.

rateL1

JRateL1_t JDETECTOR::JK40Rates::rateL1

protectedinherited

multiples rates [Hz]

Definition at line 237 of file JK40Rates.hh.

---

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

• JK40DefaultSimulator.hh