class for simulating QIE chip output More...

#include <SimQIE.h>

Public Member Functions
	SimQIE ()
	Defaut constructor.

	SimQIE (float pd, float sg, uint64_t seed)
	Main constructor.

void	setTDCThreshold (const float thr)
	Set current threshold for TDC latch.

void	setGain (const float gg=1e+6)
	Set gain of SiPM.

void	setFreq (const float sf=40)
	Set sampling frequency of QIE.

void	setNTimeSamples (const int maxts=5)
	Set the number of time samples to analyze.

float	QErr (float Q)
	Quantization error.

int	Q2ADC (float Charge)
	Digitizing input charge.

float	ADC2Q (int ADC)
	Converting ADC back to charge.

int	TDC (QIEInputPulse *pp, float T0)
	TDC of the input pulse.

std::vector< int >	Out_ADC (QIEInputPulse *pp)
	Complete set of ADCs for the pulse.

std::vector< int >	Out_TDC (QIEInputPulse *pp)
	Complete set of TDCs for the pulse.

std::vector< int >	CapID (QIEInputPulse *pp)
	Complete set of Capacitor IDs for the pulse.

bool	PulseCut (QIEInputPulse *pulse, float cut)
	Method to check if the pulse is good to be stored.

Private Attributes
int	nbins_ [5] = {0, 16, 36, 57, 64}
	Indices of first bin of each subrange.

float	edges_ [17]
	Charge lower limit of all the 16 subranges.

float	sense_ [16]
	sensitivity of the subranges (Total charge/no. of bins)

float	gain_ {1}
	QIE gain -> to convert from no. of e- to charge in fC.

float	tau_ {25}
	time period of one time sample [in ns]

int	maxts_ {0}
	No. of time samples to analyze.

float	tdc_thr_ {3.74}
	TDC threshold (default 3.74 microAmpere)

std::unique_ptr< TRandom3 >	rand_ptr {nullptr}
	Random number generator (required for noise simulation)

TRandom3 *	trg_

float	mu_ {0}
	mean of gaussian noise (Pedestal)

float	sg_ {0}
	std. dev. of gaussian noise (Actual noise level)

bool	isnoise_ {false}
	Whether noise is added to the system.

Detailed Description

class for simulating QIE chip output

Note: This should be initialized only once per simulation

Definition at line 17 of file SimQIE.h.

Constructor & Destructor Documentation

◆ SimQIE() [1/2]

trigscint::SimQIE::SimQIE ( )

Defaut constructor.

Note: if used, noise & pedestal are not simulated

Definition at line 11 of file SimQIE.cxx.

11{}

◆ SimQIE() [2/2]

trigscint::SimQIE::SimQIE	(	float	pd,
		float	sg,
		uint64_t	seed = `0`
	)

Main constructor.

Parameters

pd	pedestal value
sg	noise value
seed	random seed for noise generation

Definition at line 13 of file SimQIE.cxx.

                                                    {
  isnoise_ = true;
  if (seed == 0) {
    EXCEPTION_RAISE("RandomSeedException",
                    "QIE Noise generator not seeded (seed=0)");
  } else {
    rand_ptr = std::make_unique<TRandom3>(seed);
    trg_ = rand_ptr.get();
  }
  mu_ = PD;
  sg_ = SG;
}

References isnoise_, mu_, rand_ptr, and sg_.

Member Function Documentation

◆ ADC2Q()

float trigscint::SimQIE::ADC2Q ( int ADC )

Converting ADC back to charge.

Parameters

ADC	= ADC count

Definition at line 52 of file SimQIE.cxx.

                           {
  if (ADC <= 0) return -16;
  if (ADC >= 255) return 350000;
 
  int rr = ADC / 64;  // range
  int v1 = ADC % 64;  // temp. var
  int ss = 0;         // sub range
 
  for (int i = 1; i < 4; i++) {  // to get the subrange
    if (v1 > nbins_[i]) ss++;
  }
  // cc is unused, should it be? FIXME
  // int cc = 64 * rr + nbins_[ss];
  float temp = edges_[4 * rr + ss] + (v1 - nbins_[ss]) * sense_[4 * rr + ss] +
               sense_[4 * rr + ss] / 2;
  return (temp / gain_);
}

References edges_, gain_, nbins_, and sense_.

Referenced by trigscint::EventReadoutProducer::produce(), and trigscint::TrigScintRecHitProducer::produce().

◆ CapID()

std::vector< int > trigscint::SimQIE::CapID ( QIEInputPulse * pp )

Complete set of Capacitor IDs for the pulse.

Parameters

pp	= pointer to pulse instance

Definition at line 124 of file SimQIE.cxx.

                                              {
  std::vector<int> OP;
 
  OP.push_back(trg_->Integer(4));
  for (int i = 0; i < maxts_; i++) {
    OP.push_back((OP[i] + 1) % 4);
  }
  return OP;
}

References maxts_.

◆ Out_ADC()

std::vector< int > trigscint::SimQIE::Out_ADC ( QIEInputPulse * pp )

Complete set of ADCs for the pulse.

Parameters

pp	= pointer to pulse instance

Definition at line 88 of file SimQIE.cxx.

                                                {
  std::vector<int> OP;
 
  for (int i = 0; i < maxts_; i++) {
    float QQ = pp->Integrate(i * tau_, i * tau_ + tau_);
    OP.push_back(Q2ADC(QQ));
  }
  return OP;
}

References trigscint::QIEInputPulse::Integrate(), maxts_, Q2ADC(), and tau_.

◆ Out_TDC()

std::vector< int > trigscint::SimQIE::Out_TDC ( QIEInputPulse * pp )

Complete set of TDCs for the pulse.

Parameters

pp	= pointer to pulse instance

Definition at line 113 of file SimQIE.cxx.

                                                {
  std::vector<int> OP;
 
  for (int i = 0; i < maxts_; i++) {
    OP.push_back(TDC(pp, tau_ * i));
  }
  return OP;
}

References maxts_, tau_, and TDC().

◆ PulseCut()

bool trigscint::SimQIE::PulseCut	(	QIEInputPulse *	pulse,
		float	cut
	)

Method to check if the pulse is good to be stored.

Parameters

pulse pointer to the pulse we want to analyze

Note: ideally, checks if the amplitude is above some threshold.

Definition at line 134 of file SimQIE.cxx.

                                                     {
  if (pulse->GetNPulses() == 0) return false;
 
  //  float thr_in_pes = 1.0; instead make configurable
 
  // Only keep the pulse if it produces 1 PE (or whatever the cutoff is set to)
  // integrate over entire pulse so we catch also single-PE pulses
  float integral = 0;
  for (int i = 0; i < maxts_; i++) {
    //    if (pulse->Integrate(i * tau_, i * tau_ + tau_) >= thr_in_pes) return
    //    true;
    integral += pulse->Integrate(i * tau_, i * tau_ + tau_);
  }
  if (integral >= cut) return true;
 
  return false;
}

References trigscint::QIEInputPulse::GetNPulses(), trigscint::QIEInputPulse::Integrate(), maxts_, and tau_.

◆ Q2ADC()

int trigscint::SimQIE::Q2ADC ( float Charge )

Digitizing input charge.

Parameters

Charge = The charge to be digitized

Note: default charge unit = femto C = 1e-15 C

Definition at line 29 of file SimQIE.cxx.

                              {
  float qq = gain_ * Charge;                 // including QIE gain
  if (isnoise_) qq += trg_->Gaus(mu_, sg_);  // Adding gaussian random noise.
 
  if (qq <= edges_[0]) return 0;
  if (qq >= edges_[16]) return 255;
 
  int a = 0;
  int b = 16;
 
  // Binary search to find the subrange
  while (b - a != 1) {
    if (qq > edges_[(a + b) / 2]) {
      a = (a + b) / 2;
    } else
      b = (a + b) / 2;
  }
  return 64 * (a / 4) + nbins_[a % 4] + floor((qq - edges_[a]) / sense_[a]);
}

References edges_, gain_, isnoise_, mu_, nbins_, sense_, and sg_.

Referenced by Out_ADC().

◆ QErr()

float trigscint::SimQIE::QErr ( float Q )

Quantization error.

Definition at line 71 of file SimQIE.cxx.

                          {
  if (Q <= edges_[0]) return 0;
  if (Q >= edges_[16]) return 0;
 
  int a = 0;
  int b = 16;
  while (b - a != 1) {
    if (Q > edges_[(a + b) / 2])
      a = (a + b) / 2;
    else
      b = (a + b) / 2;
  }
  return (sense_[a] / (sqrt(12) * Q));
}

References edges_, and sense_.

Referenced by trigscint::EventReadoutProducer::produce().

◆ setFreq()

void trigscint::SimQIE::setFreq ( const float sf = 40 )

inline

Set sampling frequency of QIE.

Parameters

sf	= sampling frequency in MHz

Definition at line 53 of file SimQIE.h.

53{ tau_ = 1000 / sf; }

References tau_.

◆ setGain()

void trigscint::SimQIE::setGain ( const float gg = 1e+6 )

inline

Set gain of SiPM.

Parameters

gg = gain

Note: The multiplicated factor 16e-5 is used to convert from 1.6e-19 to fC

Definition at line 46 of file SimQIE.h.

46{ gain_ = gg * 16e-5; }

References gain_.

◆ setNTimeSamples()

void trigscint::SimQIE::setNTimeSamples ( const int maxts = 5 )

inline

Set the number of time samples to analyze.

Parameters

maxts No. of time samples to analyze

Definition at line 60 of file SimQIE.h.

60{ maxts_ = maxts; }

References maxts_.

◆ setTDCThreshold()

void trigscint::SimQIE::setTDCThreshold ( const float thr )

inline

Set current threshold for TDC latch.

Parameters

gg = gain

Definition at line 38 of file SimQIE.h.

38{ tdc_thr_ = thr; }

trigscint::SimQIE::tdc_thr_

float tdc_thr_

TDC threshold (default 3.74 microAmpere)

Definition SimQIE.h:131

References tdc_thr_.

◆ TDC()

int trigscint::SimQIE::TDC	(	QIEInputPulse *	pp,
		float	T0 = `0`
	)

TDC of the input pulse.

Parameters

pp	= pointer to a pulse instance
T0	= starting time of the pulse

Definition at line 100 of file SimQIE.cxx.

                                               {
  float thr2 = tdc_thr_ / gain_;
  if (pp->Eval(T0) > thr2) return 62;  // when pulse starts high
  float tt = T0;
  while (tt < T0 + tau_) {
    if (pp->Eval(tt) >= thr2) return ((int)(2 * (tt - T0)));
    tt += 0.1;
  }
  return 63;  // when pulse remains low all along
}

References trigscint::QIEInputPulse::Eval(), gain_, tau_, and tdc_thr_.

Referenced by Out_TDC().

Member Data Documentation

◆ edges_

float trigscint::SimQIE::edges_[17]

private

Initial value:

= {-16,   34,    158,    419,    517,   915,
                      1910,  3990,  4780,   7960,   15900, 32600,
                      38900, 64300, 128000, 261000, 350000}

Charge lower limit of all the 16 subranges.

Definition at line 116 of file SimQIE.h.

                     {-16,   34,    158,    419,    517,   915,
                      1910,  3990,  4780,   7960,   15900, 32600,
                      38900, 64300, 128000, 261000, 350000};

Referenced by ADC2Q(), Q2ADC(), and QErr().

◆ gain_

float trigscint::SimQIE::gain_ {1}

private

QIE gain -> to convert from no. of e- to charge in fC.

Definition at line 124 of file SimQIE.h.

124{1};

Referenced by ADC2Q(), Q2ADC(), setGain(), and TDC().

◆ isnoise_

bool trigscint::SimQIE::isnoise_ {false}

private

Whether noise is added to the system.

Definition at line 142 of file SimQIE.h.

142{false};

Referenced by Q2ADC(), and SimQIE().

◆ maxts_

int trigscint::SimQIE::maxts_ {0}

private

No. of time samples to analyze.

Definition at line 128 of file SimQIE.h.

128{0};

Referenced by CapID(), Out_ADC(), Out_TDC(), PulseCut(), and setNTimeSamples().

◆ mu_

float trigscint::SimQIE::mu_ {0}

private

mean of gaussian noise (Pedestal)

Definition at line 138 of file SimQIE.h.

138{0};

Referenced by Q2ADC(), and SimQIE().

◆ nbins_

int trigscint::SimQIE::nbins_[5] = {0, 16, 36, 57, 64}

private

Indices of first bin of each subrange.

Definition at line 114 of file SimQIE.h.

114{0, 16, 36, 57, 64};

Referenced by ADC2Q(), and Q2ADC().

◆ rand_ptr

std::unique_ptr<TRandom3> trigscint::SimQIE::rand_ptr {nullptr}

private

Random number generator (required for noise simulation)

Definition at line 134 of file SimQIE.h.

134{nullptr};

Referenced by SimQIE().

◆ sense_

float trigscint::SimQIE::sense_[16]

private

Initial value:

= {3.1, 6.2, 12.4, 24.8, 24.8, 49.6, 99.2, 198.4,

198.4, 396.8, 793.6, 1587, 1587, 3174, 6349, 12700}

sensitivity of the subranges (Total charge/no. of bins)

Definition at line 120 of file SimQIE.h.

120 {3.1, 6.2, 12.4, 24.8, 24.8, 49.6, 99.2, 198.4,

121 198.4, 396.8, 793.6, 1587, 1587, 3174, 6349, 12700};

Referenced by ADC2Q(), Q2ADC(), and QErr().

◆ sg_

float trigscint::SimQIE::sg_ {0}

private

std. dev. of gaussian noise (Actual noise level)

Definition at line 140 of file SimQIE.h.

140{0};

Referenced by Q2ADC(), and SimQIE().

◆ tau_

float trigscint::SimQIE::tau_ {25}

private

time period of one time sample [in ns]

Definition at line 126 of file SimQIE.h.

126{25};

Referenced by Out_ADC(), Out_TDC(), PulseCut(), setFreq(), and TDC().

◆ tdc_thr_

float trigscint::SimQIE::tdc_thr_ {3.74}

private

TDC threshold (default 3.74 microAmpere)

Definition at line 131 of file SimQIE.h.

131{3.74};

Referenced by setTDCThreshold(), and TDC().

◆ trg_

TRandom3* trigscint::SimQIE::trg_

private

Definition at line 135 of file SimQIE.h.

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

TrigScint/include/TrigScint/SimQIE.h
TrigScint/src/TrigScint/SimQIE.cxx

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ SimQIE() [1/2]

◆ SimQIE() [2/2]

Member Function Documentation

◆ ADC2Q()

◆ CapID()

◆ Out_ADC()

◆ Out_TDC()

◆ PulseCut()

◆ Q2ADC()

◆ QErr()

◆ setFreq()

◆ setGain()

◆ setNTimeSamples()

◆ setTDCThreshold()

◆ TDC()

Member Data Documentation

◆ edges_

◆ gain_

◆ isnoise_

◆ maxts_

◆ mu_

◆ nbins_

◆ rand_ptr

◆ sense_

◆ sg_

◆ tau_

◆ tdc_thr_

◆ trg_