Ядерна фізика та енергетика Nuclear Physics and Atomic Energy   ISSN: 1818-331X (Print), 2074-0565 (Online)   Publisher: Institute for Nuclear Research of the National Academy of Sciences of Ukraine   Languages: Ukrainian, English   Periodicity: 4 times per year   Open access peer reviewed journal

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V. T. Maslyuk*, P. S. Derechkei, Z. M. Bihan, P. P. Puha, N. I. Svatiuk, M. S. Liashov

Institute of Electron Physics, National Academy of Sciences of Ukraine, Uzhhorod, Ukraine

^*Corresponding author. E-mail address: volodymyr.maslyuk@gmail.com

Abstract: The paper presents the results of studying the yields of rare earth element (REE) isotopes in the fission of heavy, particularly actinide, nuclei. Mass spectra of REE isotopes (samarium, dysprosium, holmium, ytterbium) were obtained for various fission scenarios of actinide nuclei (²³⁸U, ²³²Th, ²⁴¹Am), both with and without accounting for nuclear particle emission, and at different excitation energies of the parent nucleus. Calculations were performed within the post-scission statistical approximation, which allows analyzing the statistical ordering of the two-fragment cluster ensemble. It is shown that the probabilities of REE isotope yields decrease with increasing atomic number, which may explain the peculiarities of their distribution in the Earth's crust. The presence of stable REE isotopes in trace amounts in the lithosphere can be attributed to specific features of spontaneous actinide fission accompanied by nuclear particle emission, which shifts the theoretical mass spectra toward stable REE isotopes.

Keywords: rare earth elements, actinides, statistical method, fission fragments, mass spectra, yields, lithosphere.

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