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S. A. Akimenko V. N. Bolotov G. I. Britvich K. V. Datsko V. A. Duk A. P. Filin E. N. Gushchin A. V. Inyakin V. A. Khmelnikov A. S. Konstantinov V. F. Konstantinov I. Yu. Korolkov S. V. Laptev V. A. Lebedev V. M. Leontiev A. E. Mazurov V. P. Novikov V. F. Obraztsov V. A. Polyakov A. Yu. Polyarush V. E. Postoev V. I. Romanovsky V. I. Shelikhov O. G. Tchikilev V. A. Uvarov O. P. Yushchenko 《Physics of Atomic Nuclei》2007,70(4):702-708
Results of study of the $K^ - \to \pi ^0 e^ - \overline \nu \gamma $ decay at the ISTRA+ setup are presented. We observed 4476 events of this decay. The branching ratio is found to be $R = \frac{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e \gamma )}}{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e )}}$ = (1.81±0.03(stat.)±0.07(syst.)) × 10?2 for E*γ > 10 MeV and θ*eγ > 10°. For comparison with the previous experiment the branching ratio with cuts E*γ > 10 MeV, 0.6 < cos θ*eγ < 0.9 is calculated: R = $\frac{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e \gamma )}}{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e )}}$ = (0.47±0.02(stat.) ± 0.03(syst.)) × 10?2. For the cuts E*γ > 30 MeV and θ*eγ > 20°, used in most theoretical papers, Br = (3.06 ± 0.09(stat.) ± 0.14(syst.)) × 10?4. For the asymmetry we get A ξ = ?0.015 ± 0.021. At present it is the best estimate of this asymmetry. 相似文献
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V. L. Cherginets T. P. Rebrova Yu. N. Datsko T. V. Ponomarenko R. P. Yavetsky V. Yu. Pedash 《Crystal Research and Technology》2013,48(1):16-21
CsI single crystals were grown from the melt scavenged by Y3+ (YCl3) addition in 6.7·10−4–6.7·10−3 mol·kg−1 range. The addition of the scavenger amounts comparable with the total concentration of the oxygen‐containing admixtures in molten CsI results in complete destruction of the latter. Because of this, the intensity of the band with a maximum at 2.8 eV in radioluminescence spectra caused by the oxygen‐containing admixtures (anion vacancies) considerably decreases, and the fraction of the slow 2μs‐component corresponding to these admixtures becomes lower than 0.01 (0.007). The addition of larger quantities of YCl3 leads to the appearance of a wide band with a maximum at 2.8 eV caused by cation vacancies, and the intensity of the slow 2μs‐component increases to 0.02. The maximum ratio of two faster components with the decay constants equal to 7 and 30 ns reaches 0.65:0.33 at Y3+ concentration in CsI melt equal to 6.7·10‐3 mol·kg‐1, the effective luminescence time of fastest components is ca 14 ns. The dependence of the ‘Fast/Total ratio’ on Y3+ concentration passes through its maximum (0.81) corresponding to the equivalence of Y3+ and O2− concentrations in the growth CsI melt. 相似文献
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V. L. Cherginets T. P. Rebrova Yu. N. Datsko V. F. Goncharenko N. N. Kosinov R. P. Yavetsky V. Yu. Pedash 《Crystal Research and Technology》2012,47(6):684-688
CsI single crystals treated with EuI2 as a scavenger are grown and their radioluminescence spectra and scintillation light decay curves are obtained. Addition of the quantities of the scavenger comparable with the total concentration of the oxygen‐containing admixtures in the melt results in complete destruction of the latter. In its turn, this causes the disappearance of the band with a maximum at 2.8 eV in the radioluminescence spectrum and decreases the fraction of the slow 2 µs‐component to 0.01. The addition of larger quantities of EuI2 leads to the appearance of a wide band with the maximum at 2.8 eV characterized by a decay constant of 2 µs; its intensity increases with the EuI2 concentration. The maximum ratio of two faster components with the decay constants equal to 7 and 30 ns approaches 0.58:0.41 at EuI2 concentration in CsI melt equal to 0.01 mol·kg−1. 相似文献
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Labetskaya N. A. Oreshkin V. I. Chaikovsky S. A. Datsko I. M. Rybka D. V. Van’kevich V. A. 《Russian Physics Journal》2019,62(7):1228-1234
Russian Physics Journal - Results are presented of experiments on the explosion of aluminum and titanium conductors that were carried out on a multipurpose impulse generator (MIG) (current... 相似文献
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V. I. Oreshkin S. A. Chaikovsky I. M. Datsko N. A. Labetskaya E. V. Oreshkin D. V. Rybka V. A. Van’kevich 《Bulletin of the Russian Academy of Sciences: Physics》2018,82(4):399-403
The results are presented from an experimental study of the explosion of copper conductors performed at ~2 MA current pulse with a rise time of 100 ns using the MIG generator. Using a HSFC Pro optical camera, large-scale instabilities with wavelengths of 0.2–0.5 mm are recorded on the surface of the conductor. The instabilities are tongue-shaped ejections of plasma expanding at the speed of sound in the direction opposite the gradient of the magnetic field. The obtained data are analyzed using two-dimensional magnetohydrodynamic simulation. It is shown the emergence of the observed structure was likely due to the growth of flute instabilities. 相似文献
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We perform a study of the two component fractional reaction-diffusion system with cubic nonlinearity. The linear stage of the system stability is studied for different values of the system parameters. It is shown that for a certain value of the fractional derivatives index, a new type of instability takes place with respect to perturbations of finite wave number. As a result, inhomogeneous oscillations with this wave number become unstable and lead to nonlinear oscillations which result in spatial oscillatory structure formation. 相似文献