Luminescence (version 0.4.1)

BaseDataSet.CosmicDoseRate: Base data set for cosmic dose rate calculation

Description

Collection of data from various sources needed for cosmic dose rate calculation

Usage

BaseDataSet.CosmicDoseRate

format

ll{

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 }

$$Dc = D0*(F+J*exp((altitude/1000)/H))$$

source

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

ll{

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)<="" p="">

$$y = -6*10^-8*x^3+2*10^-5*x^2-0.0025*x+0.2969$$

values.factor.Altitude

ll{

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

ll{

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.):

$$y = 0.0002*x + 4.0914$$

Version

0.1

References

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.

Examples

##load data
data(BaseDataSet.CosmicDoseRate)