Signal Integration

Integration of the spectrum including uncertainty calculation.

Usage

signal_integrate(object, background, ...)

# S4 method for class 'GammaSpectrum,missing'
signal_integrate(object, range = NULL, energy = FALSE)

# S4 method for class 'GammaSpectrum,GammaSpectrum'
signal_integrate(object, background, range = NULL, energy = FALSE)

# S4 method for class 'GammaSpectrum,numeric'
signal_integrate(object, background, range = NULL, energy = FALSE)

# S4 method for class 'GammaSpectra,missing'
signal_integrate(object, range = NULL, energy = FALSE, simplify = TRUE)

# S4 method for class 'GammaSpectra,GammaSpectrum'
signal_integrate(
  object,
  background,
  range = NULL,
  energy = FALSE,
  simplify = TRUE
)

# S4 method for class 'GammaSpectra,numeric'
signal_integrate(
  object,
  background,
  range = NULL,
  energy = FALSE,
  simplify = TRUE
)

Arguments

object: A GammaSpectrum or GammaSpectra object.
background: A GammaSpectrum object.
...: Currently not used.
range: A length-two numeric vector giving the energy range to integrate within (in keV).
energy: A logical scalar: use the energy or count threshold for the signal integration
simplify: A logical scalar: should the result be simplified to a matrix? The default value, FALSE, returns a list.

Value

If simplify is FALSE (the default) returns a list of numeric vectors (the signal value and its error), else returns a matrix.

Details

The function supports two integration techniques (see Guérin & Mercier 2011), the (1) count threshold integration and the (2) energy integration method:

The count integration technique (energy = FALSE) integrates all counts in given range:

$$ A = \frac{\Sigma_{i}^{N}S_i}{t_{live}} $$

Contrary, the energy integration techniques is the integrated cross-product of counts and corresponding energy per channel:

$$ A = \frac{\Sigma_{i}^{N}S_i \times E_i}{t_{live}} $$

$A$ is the area, $S_i$ is the signal in the $i^{th}$ channel, $N$ the number of channels, $E_i$ the energy of the corresponding channel in keV. $t_{live}$ is the live time of the measurement in s.

For calculating the uncertainties, Poisson statistics are assumed and hence the errors is calculated as:

$$ \sigma_A = \frac{\sqrt{A}}{t_{live}} $$

Note

The integration assumes that each spectrum has an energy scale.

References

Guérin, G. & Mercier, M. (2011). Determining Gamma Dose Rates by Field Gamma Spectroscopy in Sedimentary Media: Results of Monte Carlo Simulations. Radiation Measurements, 46(2), p. 190-195. doi:10.1016/j.radmeas.2010.10.003 .

Mercier, N. & Falguères, C. (2007). Field Gamma Dose-Rate Measurement with a NaI(Tl) Detector: Re-Evaluation of the "Threshold" Technique. Ancient TL, 25(1), p. 1-4.

Author

N. Frerebeau