settings | R Documentation |
Get and set preferred values for decay constants, isotopic
abundances, molar masses, fission track etch efficiences, and
etchable lengths, and mineral densities, either individually or via
a .json
file format.
settings(setting = NA, ..., fname = NA, reset = FALSE)
setting |
unless
|
... |
depends on the value for For For For For For For |
fname |
the path of a |
reset |
logical. If |
if setting=NA
and fname=NA
, returns a
.json
string
if ...
contains only the name of an isotope, isotopic ratio,
element, or mineral and no new value, then settings
returns
either a scalar with the existing value, or a two-element vector
with the value and its uncertainty.
Decay constants:
^{238}
U, ^{235}
U: Jaffey, A. H., et
al. "Precision measurement of half-lives and specific
activities of U^{235}
and U^{238}
."
Physical Review C 4.5 (1971): 1889.
^{232}
Th: Le Roux, L. J., and
L. E. Glendenin. "Half-life of ^{232}
Th.", Proceedings of the
National Meeting on Nuclear Energy, Pretoria, South Africa. 1963.
^{234}
U, ^{230}
Th: Cheng, H., Edwards, R.L.,
Shen, C.C., Polyak, V.J., Asmerom, Y., Woodhead, J., Hellstrom, J.,
Wang, Y., Kong, X., Spotl, C. and Wang, X., 2013. Improvements in
^{230}
Th dating, ^{230}
Th and ^{234}
U half-life
values, and U-Th isotopic measurements by multi-collector
inductively coupled plasma mass spectrometry. Earth and Planetary
Science Letters, 371, pp.82-91.
^{231}
Pa, ^{226}
Ra: Audi, G., Bersillon, O.,
Blachot, J. and Wapstra, A.H., 2003. The NUBASE evaluation of
nuclear and decay properties. Nuclear Physics A, 729(1), pp.3-128.
Sm: Villa, I.M., Holden, N.E., Possolo, A., Ickert, R.B.,
Hibbert, D.B. and Renne, P.R., 2020. IUPAC-IUGS recommendation on
the half-lives of ^{147}
Sm and ^{146}
Sm. Geochimica et
Cosmochimica Acta, 285, pp.70-77.
Nd: Zhao, Motian, et al. "Absolute measurements of neodymium isotopic abundances and atomic weight by MC-ICPMS." International Journal of Mass Spectrometry 245.1 (2005): 36-40.
Re: Smoliar, Michael I., Richard J. Walker, and John W. Morgan. "Re-Os ages of group IIA, IIIA, IVA, and IVB iron meteorites." Science 271.5252 (1996): 1099-1102.
Ar: Renne, Paul R., et
al. "Response to the comment by WH Schwarz et al. on "Joint
determination of ^{40}
K decay constants and
^{40}
Ar*/^{40}
K for the Fish Canyon sanidine standard,
and improved accuracy for ^{40}
Ar/^{39}
Ar
geochronology" by PR Renne et al.(2010)." Geochimica et
Cosmochimica Acta 75.17 (2011): 5097-5100.
Rb: Villa, I.M., De Bievre, P., Holden, N.E. and Renne, P.R., 2015.
"IUPAC-IUGS recommendation on the half life of ^{87}
Rb".
Geochimica et Cosmochimica Acta, 164, pp.382-385.
Lu: Soederlund, Ulf, et al. "The ^{176}
Lu decay constant
determined by Lu-Hf and U-Pb isotope systematics of Precambrian mafic
intrusions." Earth and Planetary Science Letters 219.3 (2004): 311-324.
Isotopic ratios:
Ar: Lee, Jee-Yon, et al. "A redetermination of the isotopic abundances of atmospheric Ar." Geochimica et Cosmochimica Acta 70.17 (2006): 4507-4512.
K: Garner, E.L., et al. "Absolute isotopic abundance ratios and the atomic weight of a reference sample of potassium". J. Res. Natl. Bur. Stand. A 79.6 (1975): 713-725.
Ca: Moore, L.J. and Machlan, L.A., 1972. High-accuracy determination of calcium in blood serum by isotope dilution mass spectrometry. Analytical chemistry, 44(14), pp.2291-2296.
Rb: Catanzaro, E. J., et al. "Absolute isotopic abundance ratio and atomic weight of terrestrial rubidium." J. Res. Natl. Bur. Stand. A 73 (1969): 511-516.
Sr: Moore, L. J., et al. "Absolute isotopic abundance ratios and atomic weight of a reference sample of strontium." J. Res. Natl. Bur. Stand. 87.1 (1982): 1-8.
and (for ^{87}
Sr/^{86}
Sr):
Compston, W., Berry, H., Vernon, M.J., Chappell, B.W. and Kaye, M.J., 1971. Rubidium-strontium chronology and chemistry of lunar material from the Ocean of Storms. In Lunar and Planetary Science Conference Proceedings (Vol. 2, p. 1471).
Sm: Chang, Tsing-Lien, et al. "Absolute isotopic composition and atomic weight of samarium." International Journal of Mass Spectrometry 218.2 (2002): 167-172.
Re: Gramlich, John W., et al. "Absolute isotopic abundance ratio and atomic weight of a reference sample of rhenium." J. Res. Natl. Bur. Stand. A 77 (1973): 691-698.
Os: Voelkening, Joachim, Thomas Walczyk, and Klaus G. Heumann. "Osmium isotope ratio determinations by negative thermal ionization mass spectrometry." Int. J. Mass Spect. Ion Proc. 105.2 (1991): 147-159.
Lu: De Laeter, J. R., and N. Bukilic.
"Solar abundance of ^{176}
Lu and s-process nucleosynthesis."
Physical Review C 73.4 (2006): 045806.
Hf: Patchett, P. Jonathan. "Importance of the Lu-Hf isotopic system in studies of planetary chronology and chemical evolution." Geochimica et Cosmochimica Acta 47.1 (1983): 81-91.
Pb: Stacey, J.T. and Kramers, J. "Approximation of terrestrial lead isotope evolution by a two-stage model." Earth and Planetary Science Letters, 26(2) (1975): 207-221.
U: Hiess, Joe, et
al. "^{238}
U/^{235}
U systematics in terrestrial uranium-bearing minerals."
Science 335.6076 (2012): 1610-1614.
read.data
# load and show the default constants that come with IsoplotR
json <- system.file("constants.json",package="IsoplotR")
settings(fname=json)
print(settings())
# use the decay constant of Kovarik and Adams (1932)
settings('lambda','U238',0.0001537,0.0000068)
print(settings('lambda','U238'))
# returns the 238U/235U ratio of Hiess et al. (2012):
print(settings('iratio','U238U235'))
# use the 238U/235U ratio of Steiger and Jaeger (1977):
settings('iratio','U238U235',138.88,0)
print(settings('iratio','U238U235'))
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