icarus::opdet::AsymExpPulseFunctionTool Struct Reference

Creates a AsymExpPulseFunction pulse shape. More...

Inheritance diagram for icarus::opdet::AsymExpPulseFunctionTool:

Classes
struct	Config
	Configuration parameters. More...

Public Types
using	Parameters = art::ToolConfigTable< Config >
	Tool parameter configuration. More...
Public Types inherited from icarus::opdet::SinglePhotonPulseFunctionTool
using	nanoseconds = util::quantities::nanosecond
	Convenience definition for time stored in nanoseconds. More...
using	PulseFunction_t = icarus::opdet::PhotoelectronPulseFunction< nanoseconds >
	Type of function returned. More...

Public Member Functions
	AsymExpPulseFunctionTool (Parameters const &config)
	Constructor: sets the configuration. More...
Public Member Functions inherited from icarus::opdet::SinglePhotonPulseFunctionTool
virtual	~SinglePhotonPulseFunctionTool ()=default
std::unique_ptr< PulseFunction_t >	getPulseFunction ()
	Returns an instance of the pulse function. More...

Private Member Functions
virtual std::unique_ptr < PulseFunction_t >	doGetPulseFunction () override
	Returns the function that was created at construction time. More...

Static Private Member Functions
static std::unique_ptr < PulseFunction_t >	makePulseFunction (Config const &config)
	Creates and returns a pulse function with the specified configuration. More...
static float	peakCurrentFromGain (float gain, nanoseconds raiseTau, nanoseconds fallTau)
	Computes the peak current value out of the shape and gain parameters [mA]. More...

Private Attributes
std::unique_ptr< PulseFunction_t >	fPulseFunction
	Function stored while waiting to be delivered. More...

Detailed Description

Creates a AsymExpPulseFunction pulse shape.

See Also

icarus::opdet::SinglePhotonPulseFunctionTool

This tool creates a icarus::opdet::AsymExpPulseFunction<nanosecond> function to describe a R5912 PMT pulse.

See icarus::opdet::AsymExpPulseFunction for the details of the function.

Configuration

Run lar --print-description AsymExpPulseFunctionTool (or read Config data structure) for a short explanation of the meaning of the parameters.

In addition, note that the actual amplitude in ADC counts of the pulse is composed as the product of the amplitude in charge (PeakCharge) and the charge-to-ADC conversion factor (ADC). The latter can be considered as the product of the circuitry impedance (transforming the charge into a voltage) and the digitization conversion (full digitizer range divided by the largest output value).

Finally, note that it is also possible to specify the amplitude of the function in terms of PMT gain (Gain parameter) instead of current (PeakAmplitude), in which case the peak current will be calculated to have a correct total charge.

Definition at line 66 of file AsymExpPulseFunctionTool_tool.cc.

Member Typedef Documentation

using icarus::opdet::AsymExpPulseFunctionTool::Parameters = art::ToolConfigTable<Config>

Tool parameter configuration.

Definition at line 111 of file AsymExpPulseFunctionTool_tool.cc.

Constructor & Destructor Documentation

icarus::opdet::AsymExpPulseFunctionTool::AsymExpPulseFunctionTool ( Parameters const &  config )

inline

Constructor: sets the configuration.

Definition at line 114 of file AsymExpPulseFunctionTool_tool.cc.

    : fPulseFunction(makePulseFunction(config())) {}

Member Function Documentation

virtual std::unique_ptr<PulseFunction_t> icarus::opdet::AsymExpPulseFunctionTool::doGetPulseFunction ( )

inlineoverrideprivatevirtual

Returns the function that was created at construction time.

Implements icarus::opdet::SinglePhotonPulseFunctionTool.

Definition at line 123 of file AsymExpPulseFunctionTool_tool.cc.

    { return std::move(fPulseFunction); }

auto icarus::opdet::AsymExpPulseFunctionTool::makePulseFunction ( Config const &  config )

staticprivate

Creates and returns a pulse function with the specified configuration.

Definition at line 147 of file AsymExpPulseFunctionTool_tool.cc.

{
  
  using MyFunction_t = icarus::opdet::AsymExpPulseFunction<nanoseconds>;
  using ADCcount = MyFunction_t::ADCcount;
  
  // FIXME milliampere not available yet in `electromagnetism.h`
  double peakCurrent;
  if (config.Gain().has_value()) { // peak current from gain
    if (config.PeakCurrent().has_value()) {
      throw art::Exception(art::errors::Configuration)
        << "AsymExpPulseFunctionTool: Only one configuration parameter out of '"
        << config.PeakCurrent.name() << "' (set as " << (*config.PeakCurrent())
        << ") and '" << config.Gain.name() << "' (set as " << (*config.Gain())
        << ") can be specified at once!\n";
    }
    peakCurrent = peakCurrentFromGain(
      *config.Gain(),             // gain
      config.RaiseTimeConstant(), // raiseTau
      config.FallTimeConstant()   // fallTau
      );
  }
  else { // peak current directly specified
    if (!config.PeakCurrent().has_value()) {
      throw art::Exception(art::errors::Configuration)
        << "AsymExpPulseFunctionTool: either configuration parameter '"
        << config.PeakCurrent.name() << "' or '" << config.Gain.name()
        << "' must be specified!\n";
    }
    peakCurrent = *config.PeakCurrent();
  }
  
  return std::make_unique<MyFunction_t>(
    // amplitude is a charge, so we have to twist the arm of the constructor to
    // accept it as ADC count (`value()` makes `peakCurrent` lose its unit)
//     ADCcount(config.ADC() * config.peakCurrent.value()),   // amplitude
    ADCcount(config.ADC() * peakCurrent),                  // amplitude
    config.TransitTime(),                                  // peakTime
    config.RaiseTimeConstant(),                            // raiseTau
    config.FallTimeConstant()                              // fallTau
    );
  
} // icarus::opdet::AsymExpPulseFunctionTool::makePulseFunction()

float icarus::opdet::AsymExpPulseFunctionTool::peakCurrentFromGain ( float  gain, nanoseconds  raiseTau, nanoseconds  fallTau  )

staticprivate

Computes the peak current value out of the shape and gain parameters [mA].

Definition at line 194 of file AsymExpPulseFunctionTool_tool.cc.

{
  static constexpr double electronCharge = -1.602176634e-7; // picocoulomb
  
  nanoseconds const dTau = fallTau - raiseTau; // expected positive
  float const tauRatioLog = std::log(raiseTau / fallTau); // expected negative
  
  return gain * electronCharge / dTau.value() * (
      std::exp(raiseTau / dTau * tauRatioLog)
    - std::exp(fallTau  / dTau * tauRatioLog)
    );
  
} // icarus::opdet::AsymExpPulseFunctionTool::peakCurrentFromGain()

Member Data Documentation

std::unique_ptr<PulseFunction_t> icarus::opdet::AsymExpPulseFunctionTool::fPulseFunction

private

Function stored while waiting to be delivered.

Definition at line 129 of file AsymExpPulseFunctionTool_tool.cc.

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

• AsymExpPulseFunctionTool_tool.cc