Speaker
Description
The fragments of one of the Chelyabinsk meteorite shower were investigated by methods of neutron physics. The source of thermal neutrons was the IBR-2 pulsed reactor (Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna). The neutron activation elemental analysis (NAA) of the meteorite was carried out for 10 major and 17 trace elements [1]. Comparison with the results of the neutron prompt gamma activation analysis (PGAA) for 15 elements carried out. Small-angle neutron scattering (SANS) indicated the fractality of the pore space and the exponential distribution of the thicknesses of scattering centers in the form of monodisperse flat structures.
Non-destructive research techniques, such as neutron diffraction and tomography, as well as neutron diffraction texture analysis, made it possible to obtain the volumetric distribution of mineral phases of olivine, orthopyroxene, plagioclase and troilite and discovered the presence of the kamacite phase in the studied meteorite fragment. A heterogeneous distribution of iron in olivine and orthopyroxene was found, which can identify iron-exchange processes between silicate minerals and iron-containing compounds [2].
The detailed quantitative textural analysis of another fragment of the Chelyabinsk meteorite is discussed, with the help of which it was possible to determine the predominant orientation of its main mineral phases [3]. It is suggested that the texture originated as a result of the thermobaric impact of a meteorite during its entry into the Earth's atmosphere. Moreover, the studied meteorite fragment rotated during the movement, as evidenced by its streamlined shape and fibrous type of the texture.
The study was performed in the framework of the JINR-Romania cooperation program in 2022 (topic 03-4-1128-2017/2022 and 04-4-1143-2021/2025) and JINR - Serbia Projects in 2022 (Order 178 p. 7 and 8).
[1] A. Kirillov, D. Grozdov, I. Zinicovscaia, T. Vasilenko. Elemental composition of the Chelyabinsk meteorite determined by neutron activation analysis. Journal of Radioanalytical and Nuclear Chemistry, 2022, 331(1), 249-253
[2] S.E. Kichanov, D.P. Kozlenko, A.K. Kirillov, E.V. Lukin, B. Abdurakhimov, N.M. Belozerova, A.V. Rutkauskas, T.I. Ivankina, B.N. Savenko, A structural insight into the Chelyabinsk meteorite: Neutron difraction, tomography and Raman spectroscopy study. SN Appl. Sci., 2019,1,1563.
[3] S.B. Borzakov, A. Zh. Zhomartovaa, T. I. Ivankina, A.Yu. Dmitriev, V.V. Lobachev. The Elemental and Texture Analysis of the Chelyabinsk Meteorite Fragment by Non-Destructive Neutron Methods. Physics of Particles and Nuclei Letters, 2022, 19(2), 176–182.
| Please select a main topic related to your abstract | Meteorite Analysis and Isotopic Abundance |
|---|
