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Your search keyword '"Taskaev, S."' showing total 451 results
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451 results on '"Taskaev, S."'

1. Quantum theory of neutron in magnetic field and neutron-electron collider

Author

Bogomyagkov, A., Druzhinin, V., Levichev, E., Milstein, A., Okunev, I., and Taskaev, S.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Accelerator Physics
Abstract

The paper presents solution of quantum problem of neutron propagation in the magnetic field with multipole field expansion. Rigorous solution of the Pauli equation for neutron reveals existence of two solutions, finite and infinite, for any miltipole configuration. As an example, we present detailed study of neutron motion in quadrupole and sextupole. Our predictions agree with the results of Stern-Gerlach experiment for neutrons. To verify existence of finite and infinite motion, we discuss an experiment which could be performed in the Budker Insitute of Nuclear Physics using existing equipment. We conclude with the proposal of neutron-electron intersecting ring (neutron-electron ``collider''), which, if realized, would allow to accomplish a number of important experiments devoting to study neutron internal structure.

Published
2024

8. Machine learning algorithms for optimization of magnetocaloric effect in all-d-metal Heusler alloys.

Author

Baigutlin, D. R., Sokolovskiy, V. V., Buchelnikov, V. D., and Taskaev, S. V.

Subjects
MACHINE learning, MAGNETOCALORIC effects, MAGNETIC properties, GENETIC algorithms, DENSITY functional theory
Abstract

This study examines the application of machine learning algorithms, specifically the Random Forest regression model, to optimize the magnetocaloric effect in all- d -metal Heusler alloys. The model was trained using descriptors related to the mean properties of individual atoms, the properties of simple compounds in their ground state, and measures of chemical disorder. It demonstrated high accuracy in predicting structural properties, while exhibiting moderate accuracy in predicting magnetic properties. To identify optimal alloy compositions, a genetic algorithm was used to find those with the greatest differences in magnetization during martensitic transitions. Using this combined approach, the Ni–Co–Mn–Ti alloy system was thoroughly explored, resulting in the discovery of an alloy with a maximum magnetization difference. These results are consistent with previous research based on density functional theory and highlight the effectiveness of integrating machine learning with genetic algorithms for the discovery of new materials with outstanding magnetocaloric properties. The study emphasizes the need for further refinement of models capable of accurately predicting complex magnetic interactions, which is essential for fully leveraging the potential of all- d -metal Heusler alloys in practical applications. [ABSTRACT FROM AUTHOR]

Published
2024
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14. Pele's hairs and exotic multiply twinned graphite closed-shell microcrystals in meteoritic dust of Chelyabinsk superbolide

Author

Taskaev, S., Skokov, K., Khovaylo, V., Donner, W., Faske, T., Dudorov, A., Gorkavyi, N., Savosteenko, G., Dyakonov, A., Baek, W., Kuklin, A., Avramov, P., and Gutfleisch, O.

Subjects
Condensed Matter - Materials Science
Abstract

When a space body enters Earth's atmosphere, its surface is exposed to high pressure and temperatures. The airflow tears off small droplets from the meteoroid forming a cloud of meteorite dust. Can new materials be synthesized in these unique conditions (high temperature, pressure, gaseous atmosphere, catalysts)? As a rule, meteoritic dust dissipates in the atmosphere without a trace or is mixed with terrestrial soil. The Chelyabinsk superbolide, the biggest in the 21st century, which exploded on February 15, 2013 above snowy fields of the Southern Urals, was an exception. Two new types of materials were found during an in-depth study: thread-like structures that were not previously associated with meteorite falls and unique carbon crystals with a size of several micrometers that were not observed before. The nature of formation of thread-like structures is fully similar to the nature of formation of Pele's hair during eruptions of terrestrial volcanos. Multiple twin growth mechanism of formation of closed shell graphite microcrystals was proposed based on DFT and classical/ab initio MD simulations. It was found that among several possible embryo carbon nanoclusters the C60 fullerene and polyhexacyclooctadecane -C18H12- may be the main suspects responsible for the formation of closed shell quasi-spherical and hexagonal rod graphite microcrystals., Comment: 14 pages, 6 Figures

Published
2019

17. Magnetocaloric effect in some magnetic materials in alternating magnetic fields up to 22 Hz

Author

Aliev, A. M., Batdalov, A. B., Khanov, L. N., Koledov, V. V., Shavrov, V. G., Tereshina, I. S., and Taskaev, S. V.

Subjects
Condensed Matter - Materials Science
Abstract

Direct measurements of the magnetocaloric effect (MCE) in different materials (Gd, Fe48Rh52, Ni43Mn37.9In12.1Co7 and Ni2.07Co0.09Mn0.84Ga) in alternating magnetic fields with frequencies f < 22 Hz and an amplitude deltaH = 6.2 kOe are carried out. The MCE in Gd shows inconsiderable changes with field frequency. Near paramagnetic-ferromagnetic phase transition in Ni43Mn37.9In12.1Co7 Heusler alloy a slight reduction of MCE with frequency is observed. In weak alternating fields in materials with AFM-FM magneto-structural phase transitions (Fe48Rh52, Ni43Mn37.9In12.1Co7) it is not possible to get a structural contribution to overall MCE because of irreversibility of the transitions in these fields. Near magneto-structural phase transitions the MCE in these alloys has only magnetic contribution, and does not show a significant dependence on the magnetic field frequency. In Ni2.07Co0.09Mn0.84Ga Heusler alloy the MCE vanishes at frequencies about 20 Hz. The obtained results show the increase of frequencies of operating cycles is one of the powerful methods to improve the efficiency of magnetic refrigerators in case of Gd as a refrigerant., Comment: 12 pages, 5 figures

Published
2018
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19. Integration of ITER diagnostic ports at the Budker institute

Author

Shoshin, A., Burdakov, A., Ivantsivskiy, M., Reichle, R., Udintsev, V., Guirao, J., Pak, S., Zvonkov, A., Kravtsov, D., Sorokina, N., Sulyaev, Y., Listopad, A., Gavrilenko, D., Taskaev, A., Shabunin, E., Seryomin, V., Shiyankov, S., Zaytcev, E., Seleznev, P., Semenov, A., Polosatkin, S., Taskaev, S., Kasatov, D., Shchudlo, I., Bikchurina, M., Modestov, V., Smirnov, A., Pozhilov, A., Lobachev, A., Loginov, I., Shagniev, O., Kirienko, I., and Buslakov, I.

Published
2022
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44. Study of the 11B(p,α)αα Reaction in the 0.3–2.15 MeV Energy Range of the Proton Beam.

Author

Bikchurina, M. I., Bykov, T. A., Kasatov, D. A., Sokolova, E. O., Taskaev, S. Yu., and Shuklina, A. A.

Abstract

The reliable value of the 11B(p,α)αα reaction cross-section is of importance for the proton therapy of cancer, thermonuclear fusion, and nuclear astrophysics. Despite its relevance, the mechanism of the reaction is still an open issue. The goal of the study is to obtain new data on the reaction and to update and clarify the available data in the 0.3–2.15 MeV energy range of the proton beam. The results obtained have shown that the 11B(p,α)αα reaction proceeds via two channels, 11B(p,α1)8Be* and 11B(p,α0)8Be, with unequal cross-sections, which agrees with current conceptions. A thin boron target will be studied later to measure the cross-sections of each channel. [ABSTRACT FROM AUTHOR]

Published
2024
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45. Phase transitions in Ni2+xMn1-xGa with a high Ni excess

Author

Khovaylo, V. V., Buchelnikov, V. D., Kainuma, R., Koledov, V. V., Ohtsuka, M., Shavrov, V. G., Takagi, T., Taskaev, S. V., and Vasiliev, A. N.

Subjects
Condensed Matter - Materials Science
Abstract

Ferromagnetic shape memory alloys Ni$_{2+x}$Mn$_{1-x}$Ga were studied in the range of compositions $0.16 \le x \le 0.36$. Experimental phase diagram, constructed from differential scanning calorimetry, transport and magnetic measurements, exhibits distinctive feature in a compositional interval $0.18 \le x \le 0.27$, where martensitic and magnetic transitions merge in a first-order magnetostructural phase transition ferromagnetic martensite $\leftrightarrow$ paramagnetic austenite. Observed in this interval of compositions a non-monotonous behavior of the magnetostructural phase transition temperature was ascribed to the difference in the exchange interactions of martensitic and austenitic phase and to the competition between increasing number of valence electron and progressive dilution of the magnetic subsystem which occur in the presence of a strong magnetoelastic interaction. Based on the experimental phase diagram, the difference between Curie temperature of martensite $T_C^M$ and Curie temperature of austenite $T_C^A$ was estimated. Influence of volume magnetostriction was considered in theoretical modeling in order to account for the existence of the magnetostructural phase transition over a wide range of compositions., Comment: 11 pages, 6 figures, misprint corrected

Published
2005
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