Isotopic variations of Sm, Gd, Er and Yb found in planetary materials caused by neutron-capture reactions in nature

Journal of Analytical Science and Technology
Hiroshi Hidaka

Tóm tắt

AbstractThe isotopic shifts of 149Sm–150Sm and 157Gd–158Gd have often been observed in meteorites and lunar surface materials, because they result from the neutron-capture reactions associated with secondary neutrons produced by cosmic-ray irradiation. While the Sm and Gd isotopic shifts can mainly be used for the estimation of thermal neutron fluences that of 167Er–168Er has recently been applied in the estimation of epithermal neutron fluences. The systematic isotopic dataset of Sm, Gd and Er helps us to consider the details of planetary materials’ cosmic-ray exposure conditions using the balance of the fluences between thermal and epithermal neutrons. This paper reviews a series of isotopic variations of Sm, Gd, and Er in association with neutron-capture reactions for the application of planetary sciences. As a new attempt and possibility for better understanding the neutron fluence and its energy distribution, the use of Yb isotopic variation is then discussed using two different data sources, namely lunar regolith and the Oklo natural reactors. Finally, the preliminary result for the precise isotopic measurement of Yb is presented from the viewpoint of chemical separation and instrumental improvement.

Từ khóa


Tài liệu tham khảo

Albalat E, Telouk P, Albarède F. Er and Yb isotope fractionation in planetary materials. Earth Planet Sci Lett. 2012. https://doi.org/10.1016/j.epsl.2012.08.021.

Albalat E, Blichert-Toft J, Telouk P, Albarède F. The lunar neutron energy spectrum inferred from the isotope compositions of rare-earth elements and hafnium in Apollo samples. Earth Planet Sci Lett. 2015. https://doi.org/10.1016/j.epsl.2015.07.056.

Amelin Y, Davis WJ. Geochemical test for branching decay of 176Lu. Geochim Cosmochim Acta. 2005. https://doi.org/10.1016/j.gca.2004.04.028.l.

Gauthier-Lafaye F, Holliger P, Blanc PL. Natural fission reactors in the Franceville basin. Geochim Cosmochim Acta. 1996. https://doi.org/10.1016/S0016-7037(96)00245-1.

Groopman EV, Willingham DG, Meshik AP, Pravdivtseva OV. Discovery of fissiogenic Cs and Ba capture five years after Oklo reactor shutdown. PNAS. 2018. https://doi.org/10.1073/pnas.1807267115.

Hidaka H, Holliger P. Geochemical and neutronic characteristics of the natural fossil fission reactors at Oklo and Bangombé. Gabon Geochim Cosmochim Acta. 1998. https://doi.org/10.1016/50016-7037(97)00319-0.

Hidaka H, Ebihara M, Yoneda S. Neutron capture effects on samarium, europium, and gadolinium in Apollo 15 deep drill-core samples. Meteor Planet Sci. 2000. https://doi.org/10.1111/j.1945-5100.2000.tb01438.x.

Hidaka H, Mizutani Y, Yoneda S. Estimation of thermal and epithermal neutron fluences at the lunar surface from isotopic compositions of rare earth elements. Astrophys J. 2020. https://doi.org/10.3847/1538-4357/abbffe.

Hidaka H, Bentridi SE, Gall B. Evidence of fast neutron operating in Oklo. Radiat Prot Dosimetry. 2023. https://doi.org/10.1093/rpd/ncad015.

Holliger P, Devillers C. Contribution à l’étude de la température dans les réacteurs fossils d’Oklo par la mesure du rapport isotopique du lutétium. Earth Planet Sci Lett. 1981. https://doi.org/10.1016/0012-821X(81)90209-0.

Lingenfelter RE, Canfield EH, Hampel VE. The lunar neutron flux revisited. Earth Planet Sci Lett. 1972. https://doi.org/10.1016/0012-821X(72)90153-7.

Meshik AP, Hohenberg CM, Pravdivtseva OV. Record of cycling operation of the natural nuclear reactor in the Oklo/Okelobondo area in Gabon. Phys Rev Lett. 2004. https://doi.org/10.1103/PhysRevLett.93.182302.

Mizutani Y, Hidaka H, Yoneda S. Chemical separation and determination of the isotopic compositions of dysprosium, erbium and ytterbium in geological materials by thermal ionization mass spectrometry. Geochem J. 2020. https://doi.org/10.2343/geochemj.2.0609.

Nishiizumi K, Caffee MW, Jull ATJ, Reedy RC. Exposure history of lunar meteorites Queen Alexandra Range 93069 and 94269. Meteor Planet Sci. 1996. https://doi.org/10.1111/j.1945-5100.1996.tb02122.x.

Ruffenach JC, Menes J, Devillers C, Lucas M, Hagemann R. Etudes chimiques et isotopiques de l’uranium, du plomb et de plusieurs produits de fission dans un echantillon de minerai du reacteur naturel d’Oklo. Earth Planet Sci Lett. 1976. https://doi.org/10.1016/0012-821X(72)90011-X.

Russ GP, Burnett DS, Wasserburg G. Lunar neutron stratigraphy. Earth Planet Sci Lett. 1972. https://doi.org/10.1016/0012-821X(72)90058-1.

Shollenberger Q, Brennecka GA. Dy, Er, and Yb isotopic compositions of meteorites and their components: Constraints on presolar carriers of the rare earth elements. Earth Planet Sci Lett. 2020. https://doi.org/10.1016/j.epsl.2019.115866.

Shollenberger Q, Render J, Brennecka GA. Er, Yb, and Hf isotopic compositions of refractory inclusions: an integrated isotopic fingerprint of the solar system’s earliest reservoir. Earth Planet Sci Lett. 2018. https://doi.org/10.1016/j.epsl.2018.05.007.

Spergel MS, Reedy RC, Lazareth OW, Levy PW, Slatest LA. Cosmogenic neutron-capture-produced nuclides in stony meteorites. J Geophys Res. 1986. https://doi.org/10.1029/JB091iB04p0D483.

Torrano ZA, et al. Neodymiumu-142 and samarium neutron stratigraphy of C-type asteroid (162173) Ryugu. Meteor Planet Sci. 2023. https://doi.org/10.1111/maps.14109.

Thông tin
Thông tin xuất bản

Journal of Analytical Science and Technology

Thông tin tác giả