R/Luminescence-package.R
BaseDataSet.CosmicDoseRate.RdCollection of data from various sources needed for cosmic dose rate calculation
values.cosmic.Softcomp: | data frame containing cosmic dose rates for shallow depths (< 167 g cm^-2) obtained using the "AGE" program by Rainer Gruen (cf. Gruen 2009). These data essentially reproduce the graph shown in Fig. 1 of Prescott & Hutton (1988). |
values.factor.Altitude: | data frame containing altitude factors for adjusting geomagnetic field-change factors. Values were read from Fig. 1 in Prescott & Hutton (1994). |
values.par.FJH: | data frame containing values for parameters F, J and H (read from Fig. 2 in Prescott & Hutton 1994) used in the expression |
$$Dc = D0*(F+J*exp((altitude/1000)/H))$$
The following data were carefully read from figures in mentioned
sources and used for fitting procedures. The derived expressions are used in
the function calc_CosmicDoseRate.
values.cosmic.Softcomp
| Program: | "AGE" |
| Reference: | Gruen (2009) |
| Fit: | Polynomials in the form of |
For depths between 40-167 g cm^-2:
$$y = 2*10^-6*x^2-0.0008*x+0.2535$$
(For depths <40 g cm^-2)
$$y = -6*10^-8*x^3+2*10^-5*x^2-0.0025*x+0.2969$$
values.factor.Altitude
| Reference: | Prescott & Hutton (1994) |
| Page: | 499 |
| Figure: | 1 |
| Fit: | 2-degree polynomial in the form of |
$$y = -0.026*x^2 + 0.6628*x + 1.0435$$
values.par.FJH
| Reference: | Prescott & Hutton (1994) |
| Page: | 500 |
| Figure: | 2 |
| Fits: | 3-degree polynomials and linear fits |
F (non-linear part, \(\lambda\) < 36.5 deg.):
$$y = -7*10^-7*x^3-8*10^-5*x^2-0.0009*x+0.3988$$
F (linear part, \(\lambda\) > 36.5 deg.):
$$y = -0.0001*x + 0.2347$$
J (non-linear part, \(\lambda\) < 34 deg.):
$$y = 5*10^-6*x^3-5*10^-5*x^2+0.0026*x+0.5177$$
J (linear part, \(\lambda\) > 34 deg.):
$$y = 0.0005*x + 0.7388$$
H (non-linear part, \(\lambda\) < 36 deg.):
$$y = -3*10^-6*x^3-5*10^-5*x^2-0.0031*x+4.398$$
H (linear part, \(\lambda\) > 36 deg.):
$$y = 0.0002*x + 4.0914$$
0.1
Gruen, R., 2009. The "AGE" program for the calculation of luminescence age estimates. Ancient TL, 27, pp. 45-46.
Prescott, J.R., Hutton, J.T., 1988. Cosmic ray and gamma ray dosimetry for TL and ESR. Nuclear Tracks and Radiation Measurements, 14, pp. 223-227.
Prescott, J.R., Hutton, J.T., 1994. Cosmic ray contributions to dose rates for luminescence and ESR dating: large depths and long-term time variations. Radiation Measurements, 23, pp. 497-500.
##load data
data(BaseDataSet.CosmicDoseRate)