Al2O3:C Passive Dosimeter Measurement Analysis

The function provides the analysis routines for measurements on a FI lexsyg SMART reader using Al2O3:C chips according to Kreutzer et al., 2018

Usage

analyse_Al2O3C_Measurement(
  object,
  signal_integral = NULL,
  dose_points = c(0, 4),
  recordType = c("OSL (UVVIS)", "TL (UVVIS)"),
  calculate_TL_dose = FALSE,
  irradiation_time_correction = NULL,
  cross_talk_correction = NULL,
  travel_dosimeter = NULL,
  test_parameters = NULL,
  verbose = TRUE,
  plot = TRUE,
  ...
)

Arguments

object: RLum.Analysis (required): measurement input
signal_integral: numeric (optional): signal integral, used for the signal and the background. Example: c(1:10) for the first 10 channels. If nothing is provided the full range is used
dose_points: numeric (with default): vector with dose points, if dose points are repeated, only the general pattern needs to be provided. Default values follow the suggestions made by Kreutzer et al., 2018
recordType: character (with default): input curve selection, which is passed to function get_RLum. To deactivate the automatic selection set the argument to NULL
calculate_TL_dose: logical (with default): Enables/disables experimental dose estimation based on the TL curves. Taken is the ratio of the peak sums of each curves +/- 5 channels.
irradiation_time_correction: numeric or RLum.Results (optional): information on the used irradiation time correction obtained by another experiments. If a numeric is provided it has to be of length two: mean, standard error
cross_talk_correction: numeric or RLum.Results (optional): information on the used irradiation time correction obtained by another experiments. If a numeric vector is provided it has to be of length three: mean, 2.5 % quantile, 97.5 % quantile.
travel_dosimeter: numeric (optional): specify the position of the travel dosimeter (so far measured at the same time). The dose of travel dosimeter will be subtracted from all other values.
test_parameters: list (with default): set test parameters. Supported parameters are: TL_peak_shift All input: numeric values, NA and NULL (s. Details)
verbose: logical (with default): enable/disable verbose mode
plot: logical (with default): enable/disable plot output, if object is of type list, a numeric vector can be provided to limit the plot output to certain aliquots
...: further arguments that can be passed to the plot output, supported are norm, main, mtext, title (for self-call mode to specify, e.g., sample names)

Value

Function returns results numerically and graphically:

———————————–
[ NUMERICAL OUTPUT ]
———————————–

RLum.Results-object

slot: @data

Element	Type	Description
`$data`	`data.frame`	the estimated equivalent dose
`$data_table`	`data.frame`	full dose and signal table
`test_parameters`	`data.frame`	results with test parameters
`data_TDcorrected`	`data.frame`	travel dosimeter corrected results (only if TD was provided)

Note: If correction the irradiation time and the cross-talk correction method is used, the De values in the table data table are already corrected, i.e. if you want to get an uncorrected value, you can use the column CT_CORRECTION remove the correction

slot: @info

The original function call

————————
[ PLOT OUTPUT ]
————————

OSL and TL curves, combined on two plots.

Details

Working with a travel dosimeter

The function allows to define particular aliquots as travel dosimeters. For example: travel_dosimeter = c(1,3,5) sets aliquots 1, 3 and 5 as travel dosimeters. These dose values of this dosimeters are combined and automatically subtracted from the obtained dose values of the other dosimeters.

Calculate TL dose

The argument calculate_TL_dose provides the possibility to experimentally calculate a TL-dose, i.e. an apparent dose value derived from the TL curve ratio. However, it should be noted that this value is only a fall back in case something went wrong during the measurement of the optical stimulation. The TL derived dose value is corrected for cross-talk and for the irradiation time, but not considered if a travel dosimeter is defined.

Calculating the palaeodose is possible without any TL curve in the sequence!

Test parameters

TL_peak_shift numeric (default: 15):

Checks whether the TL peak shift is bigger > 15 K, indicating a problem with the thermal contact of the chip.

stimulation_power numeric (default: 0.05):

So far available, information on the delivered optical stimulation are compared. Compared are the information from the first curves with all others. If the ratio differs more from unity than the defined by the threshold, a warning is returned.

Function version

0.2.6

How to cite

Kreutzer, S., 2024. analyse_Al2O3C_Measurement(): Al2O3:C Passive Dosimeter Measurement Analysis. Function version 0.2.6. In: Kreutzer, S., Burow, C., Dietze, M., Fuchs, M.C., Schmidt, C., Fischer, M., Friedrich, J., Mercier, N., Philippe, A., Riedesel, S., Autzen, M., Mittelstrass, D., Gray, H.J., Galharret, J., Colombo, M., 2024. Luminescence: Comprehensive Luminescence Dating Data Analysis. R package version 0.9.26. https://r-lum.github.io/Luminescence/

References

Kreutzer, S., Martin, L., Guérin, G., Tribolo, C., Selva, P., Mercier, N., 2018. Environmental Dose Rate Determination Using a Passive Dosimeter: Techniques and Workflow for alpha-Al2O3:C Chips. Geochronometria 45, 56-67.

Author

Sebastian Kreutzer, Institute of Geography, Heidelberg University (Germany) , RLum Developer Team

Examples

##load data
data(ExampleData.Al2O3C, envir = environment())

##run analysis
analyse_Al2O3C_Measurement(data_CrossTalk)
#> Warning: [analyse_Al2O3C_Measurement()] TL peak shift detected for aliquot position 1, check the curves
#>  [analyse_Al2O3_Measurement()] #1 DE: 0 ± 0

#>  ... (#1 | ALQ POS: 1)
#>  [analyse_Al2O3_Measurement()] #2 DE: 0 ± 0

#>  ... (#2 | ALQ POS: 2)
#> 
#>  [RLum.Results-class]
#> 	 originator: analyse_Al2O3C_Measurement()
#> 	 data: 3
#>  	 .. $data : data.frame
#> 	 .. $data_table : data.frame
#> 	 .. $test_parameters : data.frame
#> 	 additional info elements:  1