JDETECTOR::JK40DefaultSimulatorInterface Class Reference

Default K40 simulator interface. More...

#include <JK40DefaultSimulatorInterface.hh>

Inheritance diagram for JDETECTOR::JK40DefaultSimulatorInterface:

Classes
struct	JBuffer1D_t
	1D-linear buffer. More...
struct	JBuffer2D_t
	2D-square buffer. More...

Public Member Functions
virtual double	getSinglesRate (const JPMTIdentifier &pmt) const =0
	Get singles rate as a function of PMT. More...
virtual double	getMultiplesRate (const JModuleIdentifier &module, const int M) const =0
	Get multiples rate as a function of optical module. More...
virtual double	getProbability (const double ct) const =0
	Get probability of coincidence. More...
virtual void	generateHits (const JModule &module, const JTimeRange &period, JModuleData &output) const
	Generate hits. More...

Static Public Member Functions
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 void	setSigma (const double sigma)
	Set intrinsic time smearing of K40 coincidences. More...

Protected Member Functions
	JK40DefaultSimulatorInterface ()
	Default constructor. More...

Static Private Member Functions
static double &	get_sigma ()
	Get intrinsic time smearing of K40 coincidences. 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...

Detailed Description

Default K40 simulator interface.

This class provides for a default implementation of the JK40Simulator interface which is based on a set of virtual methods. These methods constitute a user interface to the K40 background simulation.

Definition at line 35 of file JK40DefaultSimulatorInterface.hh.

Constructor & Destructor Documentation

JDETECTOR::JK40DefaultSimulatorInterface::JK40DefaultSimulatorInterface ( )

inlineprotected

Default constructor.

Definition at line 72 of file JK40DefaultSimulatorInterface.hh.

    {}

Member Function Documentation

virtual double JDETECTOR::JK40DefaultSimulatorInterface::getSinglesRate ( const JPMTIdentifier &  pmt ) const

pure virtual

Get singles rate as a function of PMT.

Parameters

pmt	PMT identifier

Returns

rate [Hz]

Implemented in JDETECTOR::JK40DefaultSimulator, and JTRIGGER::JK40RunByRunSimulator.

virtual double JDETECTOR::JK40DefaultSimulatorInterface::getMultiplesRate ( const JModuleIdentifier &  module, const int  M  ) const

pure virtual

Get multiples rate as a function of optical module.

Parameters

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

Returns

rate [Hz]

Implemented in JDETECTOR::JK40DefaultSimulator.

virtual double JDETECTOR::JK40DefaultSimulatorInterface::getProbability ( const double  ct ) const

pure virtual

Get probability of coincidence.

Parameters

ct	cosine space angle between PMT axes

Returns

probability

Implemented in JDETECTOR::JK40DefaultSimulator.

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

inlinevirtual

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&) {}
          }
        }
      }
    }

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

inlinestatic

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.");
      }
    }

static double JDETECTOR::JK40DefaultSimulatorInterface::getSigma ( )

inlinestatic

Get intrinsic time smearing of K40 coincidences.

Returns

sigma [ns]

Definition at line 278 of file JK40DefaultSimulatorInterface.hh.

    {
      return get_sigma();
    }

static void JDETECTOR::JK40DefaultSimulatorInterface::setSigma ( const double  sigma )

inlinestatic

Set intrinsic time smearing of K40 coincidences.

Parameters

sigma

sigma [ns]

Definition at line 289 of file JK40DefaultSimulatorInterface.hh.

    {
      get_sigma() = sigma;
    }

static double& JDETECTOR::JK40DefaultSimulatorInterface::get_sigma ( )

inlinestaticprivate

Get intrinsic time smearing of K40 coincidences.

Returns

sigma [ns]

Definition at line 300 of file JK40DefaultSimulatorInterface.hh.

    {
      static double sigma = 0.5;

      return sigma;
    }

Member Data Documentation

JBuffer2D_t JDETECTOR::JK40DefaultSimulatorInterface::probability2D

mutableprivate

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 313 of file JK40DefaultSimulatorInterface.hh.

JBuffer1D_t JDETECTOR::JK40DefaultSimulatorInterface::probability1D

mutableprivate

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 320 of file JK40DefaultSimulatorInterface.hh.

JBuffer1D_t JDETECTOR::JK40DefaultSimulatorInterface::probabilityND

mutableprivate

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 327 of file JK40DefaultSimulatorInterface.hh.

JBuffer1D_t JDETECTOR::JK40DefaultSimulatorInterface::rateL1_Hz

mutableprivate

Multiples rate as a function of the multiplicity.

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

Definition at line 333 of file JK40DefaultSimulatorInterface.hh.

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

• JK40DefaultSimulatorInterface.hh