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Project Status: Active – The project has reached a stable, usable state and is being actively developed.

DOI CRAN DOI

SWH

Overview

gamma is intended to process in-situ gamma-ray spectrometry measurements for luminescence dating. This package allows to import, inspect and (automatically) correct the energy scale of the spectrum. It provides methods for estimating the gamma dose rate by the use of a calibration curve. This package only supports Canberra CNF and TKA and Kromek SPE files.

The gammaShiny package provides an enhanced graphical user interface for the main applications of gamma.

To cite gamma in publications use:

  Lebrun B, Frerebeau N, Paradol G, Guérin G, Mercier N, Tribolo C,
  Lahaye C, Rizza M (2020). "gamma: An R Package for Dose Rate
  Estimation from In-Situ Gamma-Ray Spectrometry Measurements."
  _Ancient TL_, *38*(2), 1-5.

  Frerebeau N, Lebrun B, Paradol G, Kreutzer S (2024). _gamma: Dose
  Rate Estimation from in-Situ Gamma-Ray Spectrometry_. Université
  Bordeaux Montaigne, Pessac, France. doi:10.5281/zenodo.2652393
  <https://doi.org/10.5281/zenodo.2652393>, R package version 1.1.0.

Installation

You can install the released version of gamma from CRAN with:

And the development version from GitHub with:

# install.packages("remotes")
remotes::install_github("crp2a/gamma")

Usage

## A minimal example
library(gamma)

## Find the full path to the spectrum file
spc_file <- system.file("extdata/LaBr.CNF", package = "gamma")
## Import the spectrum
spectrum <- read(spc_file)

## Set the expected channel/energy peaks for the energy scale calibration
## Spectrum pre-processing and peak detection
peaks <- spectrum |>
  signal_slice() |>
  signal_stabilize(f = sqrt) |>
  signal_smooth(method = "savitzky", m = 21) |>
  signal_correct(method = "SNIP", n = 100) |>
  peaks_find()

## Set the energy values (in keV)
set_energy(peaks) <- c(238, NA, NA, NA, 1461, NA, NA, 2615)

## Calibrate the energy scale
calib <- energy_calibrate(spectrum, peaks)

## Inspect peaks
plot(calib, peaks)

## Estimate the gamma dose rate of a set of spectra
## You may want to give extra attention to the energy calibration step
spc_file <- system.file("extdata/BDX_LaBr_1/test", package = "gamma")
spectra <- read(spc_file)

## Load the calibration curve for the dose rate estimation
## As this curve is instrument specific, you will have to build your own
data("BDX_LaBr_1", package = "gamma")
plot(BDX_LaBr_1)

## Estimate the gamma dose rate
(doses <- dose_predict(BDX_LaBr_1, spectra))
name signal_Ni signal_err_Ni dose_Ni dose_err_Ni signal_NiEi signal_err_NiEi dose_NiEi dose_err_NiEi dose_final dose_err_final
20110523204008 8.604666 0.2691316 252.2866 10.372500 7626.493 8.747617 220.6747 5.495079 236.4806 11.366900
20110523210008 8.775092 0.2166075 257.3316 9.354274 7577.302 7.021326 219.1303 5.454610 238.2309 10.495729
20110527205316 8.445976 0.1546491 247.5890 8.012680 7064.449 5.009961 203.0288 5.052359 225.3089 9.198048
20130809172451 30.218479 0.2549754 892.1003 24.967288 27667.473 8.089989 849.8817 21.142124 870.9910 32.614162
20130813181639 36.062314 0.2853286 1065.0899 29.644785 33243.050 9.028097 1024.9325 25.496544 1045.0112 39.010062
20160717175757 19.190250 0.3635398 565.6418 18.510895 16419.873 11.495584 496.7518 12.361511 531.1968 21.838611
20160717181052 16.303659 0.2837191 480.1928 15.297869 14033.831 9.033011 421.8396 10.496701 451.0162 18.231817
20160717182601 16.896441 0.2557337 497.7403 15.269850 14493.495 8.131459 436.2712 10.854933 467.0058 18.446627

Contributing

Please note that the gamma project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.

Acknowledgements

This work received a state financial support managed by the Agence Nationale de la Recherche (France) through the program Investissements d’avenir (ref. 10-LABX-0052 and 11-IDEX-0001).