BaseDataSet.CosmicDoseRate {Luminescence}

Base data set for cosmic dose rate calculation

Description

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

Format

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))

Version

0.1

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

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

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)