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Searches for nuclear-stable multineutrons among products originating from the fission of 238U nuclei that is induced by 62-MeV alpha particles were performed by the activation method. The reaction involving the transfer of four neutrons and occurring on the isotope 88Sr, 88Sr( x n, (x ? 4) n)92Sr??92Y, was used to identify nuclear-stable multineutrons. A line at the energy of E = 1384 keV was found in the measured gamma-ray spectra of irradiated samples. This line, together with the measured time dependence of the decrease in its activity, is indicative of the formation of the beta-active nucleus 92Sr. This result was reproduced in repeated measurements. It suggests the possible existence of nuclear-stable multineutrons ( x n) for x ?? 6. The differential cross section for the x n yield at an angle of 30° in the alpha-particle-induced fission of 238U was about 6 × 10?2 mb/sr. 相似文献
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V. G. Grebinnik V. N. Duginov V. A. Zhukov S. Kapusta A. B. Lazarev V. G. Olshevsky V. Y. Pomjakushin S. N. Shilov D. T. Bezhitadze I. I. Gurevich B. F. Kirillov E. P. Krasnoperov B. A. Nikolsky A. V. Pirogov A. N. Ponomarev V. A. Suetin G. F. Tavadze I. P. Borovinskaya M. D. Nersesyan A. G. Peresada Y. F. Eltzev V. R. Karasik O. E. Omelyanovsky 《Hyperfine Interactions》1990,61(1-4):1093-1096
We report the results of μSR investigations of the ceramic samples La2-xSrxCuO4-σ (x=0.1, 0.15, 0.25) and ReBa2Cu3O7-σ (Re=Er, Ho, Y0.5Ho0.5) in the external magnetic field 0–800 Oe. The measurements were performed by the ZFC and FC methods. The irreversibility effects were studied at several temperatures by measuring the mean value and the width of the magnetic field distribution on the muon in the step by step procedure of increasing and subsequent decreasing of the external field. The temperature dependences of the magnetic penetration depth perpendicular to the basal plane λ⊥ were obtained. For the lanthanum sample with 0.15 of Sr its value at the zero temperature is λ⊥ (0)=2400 Å, for Er-Ba-Cu-O λ⊥ (0)=1600 Å. 相似文献
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V. G. Grebinnik V. N. Duginov V. A. Zhukov S. Kapusta A. B. Lazarev V. G. Olshevsky V. Y. Pomjakushin S. N. Shilov I. I. Gurevich B. F. Kirillov B. A. Nikolsky A. V. Pirogov A. N. Ponomarev V. A. Suetin I. P. Borovinskaya M. D. Nersesyan A. G. Persada Y. F. Eltzev V. R. Kapasik O. E. Omelyanovski 《Hyperfine Interactions》1990,61(1-4):1085-1088
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L. L. Doskolovich S. N. Khonina V. V. Kotlyar I. V. Nikolsky V. A. Soifer G. V. Uspleniev 《Optical and Quantum Electronics》1993,25(11):801-814
Using numerical and analytical approaches, we have computed the optical elements (focusators) required for focusing laser light into a narrow ring, a wide ring and a set of rings. A numerical comparison of the various computational techniques is reported. Finally the operation of a fabricated rotor axicon to focus light into a ring is reported. 相似文献
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S. G. Barsov A. L. Getalov V. G. Grebinnik V. A. Gordeev I. I. Gurevich Yu. M. Kagan A. I. Klimov S. P. Kruglov L. A. Kuzmin A. B. Lazarev S. M. Mikirtychyants B. A. Nikolsky A. V. Pirogov A. N. Ponomarev V. I. Selivanov G. V. Shcherbakov V. A. Suetin V. A. Zhukov 《Hyperfine Interactions》1984,17(1-4):145-149
A muon spin relaxation rate in a super-pure sample of bismuth has been measured. The experimental data and the theory of coherent diffusion in crystalline lattices with shifted levels are compared. 相似文献
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V. G. Grebinnik V. N. Duginov V. A. Zhukov S. Kapusta A. B. Lazarev V. G. Olshevsky V. Yu. Pomjakushin S. N. Shilov I. I. Gurevich B. F. Kirillov E. P. Krasnoperov B. A. Nikolsky A. V. Pirogov A. N. Ponomarev V. A. Suetin A. I. Morozov 《Hyperfine Interactions》1991,63(1-4):241-247
High temperature superconductors HoBa2Cu3O7−δ (T
c
≅93 K), Ho0.5Y0.5Ba2Cu3O7−δ (T
c
≅93 K) and ErBa2Cu3O7−δ (T
c
≅95 K) were investigated by the zero-field μSR-technique. The muon spin depolarisation rate connected with the fluctuation
frequency of rare-earth ion magnetic moments was measured. It was found that the samples with holmium show a fast increase
of the muon spin depolarisation rate at temperatures below 20 K, while in ErBa2Cu3O7−δ the depolarisation rate remains low in the whole temperature region studied (4.2 K-270 K). The sharp difference between the
behaviours of the muon spin depolarisation rate may be explained by the difference between the ground state of Ho3+ and Er3+ ions in the crystalline field of the lattice. 相似文献
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S. G. Barsov A. L. Getalov G. Grebinnik I. I. Gurevich B. F. Kirillov A. I. Klimov S. P. Kruglov L. A. Kuzmin A. B. Lazarev S. M. Mikirtychyants N. I. Moreva B. A. Nikolsky A. V. Pirogov A. N. Ponomarev V. I. Selivanov G. V. Shcherbakov S. N. Shilov V. A. Suetin V. A. Zhukov 《Hyperfine Interactions》1986,31(1-4):339-343
It is shown that the temperature dependence Λ (T) of the muon spin relaxation rate in the paramagnetic state of dysprosium
and holmium does not reveal any singularity at T−>TN′ where TN is the Neel temperature. This result contradicts the assumption of the second-order antiferromagnetic phase-transition in
these metals and is in good agreement with computations within the renormalization group method. 相似文献
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V. G. Grebinnik V. N. Duginov V. A. Zhukov S. Kapusta A. B. Lazarev V. G. Olshevsky V. Yu. Pomjakushin S. N. Shilov I. K. Ageenkova A. M. Brjazkalo B. F. Kirillov A. V. Pirogov B. A. Nikolsky A. N. Ponomarev V. N. Sumarokov A. G. Chistov S. Safrata J. Sebek D. Niznansky T. Hanslik H. Sichova 《Hyperfine Interactions》1991,63(1-4):117-122