共查询到20条相似文献,搜索用时 15 毫秒
1.
N. N. Kalmykov G. V. Kulikov V. P. Sulakov Yu. A. Fomin 《Moscow University Physics Bulletin》2009,64(5):536-540
Data on muon and electron components of extensive air showers (EAS) (obtained with the EAS MSU array) were used to derive
the primary cosmic ray (PCR) mass composition. It is shown that for energies beyond the knee at energy 3 × 1015 eV the abundance of heavy nuclei increases with energy. But at energies above 1017 eV the abundance of light nuclei starts to grow. The primary cosmic ray spectrum in the range 1015–1018 eV is analyzed. It is shown that at energies above 1017 eV the additional component appears and it differs from the bulk of Galactic cosmic rays generated by shocks in SN remnants. 相似文献
2.
A. A. Mikhailov 《JETP Letters》2004,79(4):141-143
The arrival directions of extensive air showers are analyzed on the basis of world data. It is found that the zenith-angle distributions for energies E>1019 eV and E>4×1019 eV differ from each other. According to our estimates, the SUGAR array detects no showers above 1020 eV. The mass composition of ultrahigh-energy cosmic rays is estimated. Cosmic rays with E>4×1019 eV most likely consist of superheavy nuclei. 相似文献
3.
This paper analyses the possibility of separating distinct groups of nuclei of primary cosmic rays with energies of 1015–1016 eV from the data on the spatial-angular distribution of Cherenkov light in extensive air showers. The paper shows that using
an array of a few (3–4) telescopes with a moderately sized angular cell ∼0.5° placed at a distance ∼100 m from one another,
one can achieve almost complete separation of the showers initiated by these nuclei (the Bayesian classification error is
a few percentage points for the case of separating primary protons and nitrogen nuclei). The authors propose new parameters
of the angular Cherenkov image that can greatly enhance the separability of the shower classes as compared to the approach
based on the traditional parameters. 相似文献
4.
E. N. Gudkova N. M. Nesterova N. M. Nikolskaya V. P. Pavlyuchenko 《Bulletin of the Russian Academy of Sciences: Physics》2017,81(4):457-459
The primary cosmic ray energy spectrum at energies of 1015 to 5 × 1017 eV is presented using the results from observations by the Tien Shan HADRON array. The spectrum was obtained from the spectrum of showers according to the number of electrons using a new way of determining the parameter of spatial distribution function S of electrons. The energy spectrum can be extended to low energies up to 2 × 1013 eV using data from separate experiments at the former Tien Shan array. Conclusions are drawn regarding changes in the form of the spectrum and its chemical composition at energies over 1016 eV. The spectrum is compared to the results from the TUNKA installation. 相似文献
5.
R. A. Antonov D. V. Chernov Yu. I. Stozhkov 《Bulletin of the Lebedev Physics Institute》2016,43(2):80-86
An Antarctic balloon experiment for measuring the energy spectrum and elemental composition of cosmic rays in the ultrahigh-energy range (1018–1020) eV is proposed. Scientific equipment will measure fluorescence caused by an extensive air shower formed in the atmosphere by an ultrahigh energy particle and Cherenkov light of this shower reflected from a snow surface. It is assumed that the balloon will fly in the circumpolar orbit in Antarctica at a height of ~25 km for (2–3) winter (in the Southern Hemisphere)months. For this time, ~3000 events caused by particles with energies above 1018 eV and (200–300) events caused by particles with energies above 1019 eV will be detected. 相似文献
6.
A. V. Glushkov 《Physics of Atomic Nuclei》2003,66(7):1252-1259
Results are presented that were obtained from an analysis of arrival directions for cosmic rays of energy in the range E 0 ≈ 1016.9–17.2 eV that were recorded by the Yakutsk array between 1974 and 2001 at zenith angles of θ ≤ 45°. It is shown that a considerable part of them form clusters that have small-scale cellular structure. In all probability, these showers are generated by neutral particles of an extragalactic origin. 相似文献
7.
Data from the Yakutsk extensive air shower array for the period 1974–2004 are used to analyze the energy spectrum and anisotropy of primary cosmic rays (PCRs) with energy E0≥1017 eV. The spectra from different regions of the sky are shown to differ in shape. Enhanced and reduced particle fluxes come from the disks of the Galaxy and the Supergalaxy (the Local Supercluster of galaxies) at E0≥5×1018 eV and E0≤ (2?3)×1018 eV, respectively. This is interpreted as a manifestation of the possible interaction between extragalactic PCRs and the matter of these spatial structures. 相似文献
8.
A. V. Glushkov 《Journal of Experimental and Theoretical Physics》2010,111(1):57-63
The arrival directions of primary cosmic ray particles with energies E
0 ≥ 1017 eV and zenith angles θ ≤ 60° recorded on the Yakutsk array over the period 1974–2009 are analyzed. These events are shown
to have different anisotropies in different energy ranges. 相似文献
9.
T. T. Barnaveli T. T. BarnaveliJr. N. M. Nesterova I. V. Khaldeeva A. P. Chubenko N. A. Eristavi 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(4):503-505
The distribution of energy fluxes of the hadron component of extensive air showers through an ion-ization calorimeter in the primary-energy range ~3 × 1013?1016 eV is considered. Extensive air showers with zero and minimum energy fluxes of the hadron component are selected. It is concluded that the primary-energy range E 0 ≈ 1 × 1014?2 × 1015 eV contains isotropic γ radiation with a spectrum close to bell-shaped, having a maximum near E 0 ≈ 2.2 × 1014 eV and an additional peak near E 0 ≈ 1.6 × 1015 eV. 相似文献
10.
O. V. Vedeneev 《Physics of Atomic Nuclei》2009,72(2):250-256
The results of a reanalysis of experimental data on extensive-air-shower radioemission that were obtained previously at the Moscow State University array for studying extensive air showers are presented. The lateral distribution of radioemission is given for showers characterized by a primary energy of 4 × 1017 eV and a zenith angle of θ = 35°. On the basis of an analysis of a lateral distribution of radioemission, the average value of the shower-maximum depth at a primary energy of 4 × 1017 eV is estimated at X max = 655 ± 13 g/cm2. Estimates of themass content of primary radiation that were obtained from an analysis of the distribution of X max are compatible with the hypothesis that the role of light nuclei becomes more pronounced at energies above 1017 eV. 相似文献
11.
Yu. B. Burkatovskaya V. M. Bystritsky G. N. Dudkin A. R. Krylov A. S. Lysakov S. Gazi J. Huran B. A. Nechaev V. N. Padalko A. B. Sadovsky Yu. G. Tuleushev M. Filipowicz A. V. Philippov 《Physics of Particles and Nuclei Letters》2016,13(2):190-197
The cross section of the reaction D(4He, γ)6Li with titanium and zirconium deuterides as targets is measured for incident 4He+ ion energies of 30 and 36 keV, respectively. The ion beam is generated by a Hall pulsed plasma accelerator. For the first time, upper limits on the cross section of the reaction D(4He, γ)6Li at ultralow energies are imposed (at 90% confidence level): σ ≤ 1.2 × 10?35 cm2 for the TiD2 target and E(4He+) = 30 keV, and σ ≤ 7 × 10?36 cm2 for the ZrD2 target and E(4He+) = 36 keV 相似文献
12.
A. V. Glushkov 《Physics of Atomic Nuclei》2012,75(2):203-208
The Pierre Auger Collaboration discovered, in a solid angle of radius about 18°, a local group of cosmic rays having energies
in the region E
0 ≥ 5.5 × 1019 eV and coming from the region of the Gen A radio galaxy, whose galactic coordinates are l
G = 309.5° and b
G = 19.4°. Near it, there is the Centaur supercluster of galaxies, its galactic coordinates being l
G = 302.4° and b
G = 21.6°. It is noteworthy that the Great Attractor, which may have a direct bearing on the observed picture, is also there. 相似文献
13.
A. V. Glushkov 《Physics of Atomic Nuclei》2011,74(1):58-66
The results obtained by analyzing arrival directions for primary cosmic particles characterized by energies in the region
E
0 ⩾ 1017 eV and zenith angles in the range θ ⩽ 60° and detected at the Yakutsk array for studying extensive air showers (EASs) over the period spanning 1974 and 2009
are presented. It is shown that these events exhibit different anisotropies in different energy intervals. 相似文献
14.
Results are presented that were obtained by analyzing arrival directions for cosmic rays recorded by the Yakutsk array between 1974 and 2001 in the energy range E0=1017.6–17.9 eV for zenith angles in the region θ≤53°. It is shown that their flux consists of two components—an isotropic (about 75%) and a cluster (about 25%) one—that are characterized by sharply different degrees of anisotropy. At E0=1017.7–17.8 eV, the observed showers are found to be strongly correlated with the Supergalaxy plane. 相似文献
15.
N. E. Sluchanko A. N. Azarevich A. V. Bogach S. Yu. Gavrilkin V. V. Glushkov S. V. Demishev A. V. Dukhnenko A. B. Lyashchenko K. V. Mitsen V. B. Filipov 《JETP Letters》2011,94(8):642-646
The specific heat of the ZrB12 compound in the normal and superconducting states (T
C
≈ 6 K) has been studied in the 1.9–7 K temperature range for high-quality single crystals with different relative contents
of boron isotopes. For Zr10B12, ZrnatB12, and Zr11B12 dodecaborides, the electron density of states and the electronphonon coupling constant, λe-ph ∼ 0.4, are found. The dependence of the thermodynamic and upper critical fields, as well as of the Ginzburg-Landau parameter
(κ = 0.8–1.14) on temperature and isotope composition is determined. The results suggest the existence of the magnetic field
induced phase transition at T* = 4–5 K, which is not related to the transition from type-I to type-II superconductivity. The possibilities of the existence
of two-gap superconductivity and a structural phase transition at T* in zirconium dodecaboride are discussed. 相似文献
16.
L. González-Sánchez E. Bodo F. A. Gianturco 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(1):65-72
An ab initio computed potential energy surface is employed to
evaluate the interaction of the OH+(3Σ -) molecule with
4He(1S) atom and an analytic fitting of the raw points is
directly employed in quantum scattering calculations at ultralow
collision energies. The Hund's case (b) chosen to handle the
spin-rotation coupling allows to extract from the numerous inelastic
cross sections the relative importance of pure “spin flip" vis-à-
vis rotational cooling cross sections. The final rates of all the
above processes as a function of the initial |N〉 state are
analysed in detail and possible propensity rules are discussed. 相似文献
17.
A comparative analysis of the predictions of the collinear parton model and the k T -factorization approach is performed for the case of the D*-meson electroproduction at the HERA ep collider. It is shown that, owing to effectively taking into account, in noncollinear distributions, next-order corrections in the strong coupling constant α s , the k T -factorization approach increases, in contrast to the predictions of the collinear parton model, the absolute value of the cross sections for charmed-meson electroproduction by approximately a factor of 1.5 to 2. As a result, the agreement with experimental data is improved. This is not so only for the pseudorapidity spectrum, whose shape differs considerably from the experimental one and depends greatly on the choice of parametrization of the noncollinear gluon distribution within the proton. 相似文献
18.
B. Erdemchimeg A. G. Artukh S. Davaa S. A. Klygin G. A. Kononenko G. Khuukhenkhuu D. A. Kyslukha S. M. Lukyanov T. I. Mikhailova Yu. M. Sereda Yu. E. Penionzhkevich A. N. Vorontzov C. Borcea F. Rotaru M. Stanoiu 《Bulletin of the Russian Academy of Sciences: Physics》2016,80(3):223-226
Preliminary results of measurements of the total reaction cross sections σR for weakly-bound 6,8He and 8,9Li nuclei at energy range (25–45)/A MeV on 27Al and 208Pb targets are presented. The secondary beams of 6,8He and 8,9Li were produced by bombardment of the 11B (33 A MeV) primary beam on Be (89 mg cm–2) target and separated by COMBAS fragment-separator. In dispersive focal plane a horizontal slit defined the momentum acceptance as 1% and a wedge degrader of 200 μm Al was installed. The Bρ of the second section of the fragment-separator was adjusted for measurements in energy range (25–45)/A MeV. The secondary products were detected by a telescope consisting of two Si ΔE detectors 300, 1000 μm and E-detector, which consisted of nine CsI/Tl granules. 相似文献
19.
A. V. Glushkov 《Physics of Atomic Nuclei》2007,70(2):326-341
Results are presented that were obtained by analyzing the energy spectrum and anisotropy of E 0 ≥ 1017 eV primary cosmic rays on the basis of data accumulated at the Yakutsk array for studying extensive air showers over the period between 1974 and 2004. It is shown that spectra corresponding to different regions of the sky differ in shape. Particle fluxes going from the Galaxy and Supergalaxy (a local supercluster of galaxies) disks are enhanced for E 0 ≥ 5 × 1018 eV and are reduced for E 0 ≤ (2–3) × 1018 eV. This observation is interpreted as a manifestation of the possible interaction between extragalactic primary cosmic rays and matter of the above structures of space. 相似文献
20.
Unique combination of ionic conductivity and anisotropic physical properties in ionic liquid crystals leads to new dynamic properties exploited in modern technological applications. Structural and dynamics information at atomic level for molecules and ions in mesophases can be obtained by nuclear magnetic resonance (NMR) spectroscopy through the measurements of dipole–dipole spin couplings. While 13C–1H and 15N–1H dipolar NMR spectra can be routinely acquired in samples with natural isotopic abundance, recording 15N–13C dipolar NMR spectra is challenging because of the unfavourable combination of two rare isotopes. In the present study, an approach to measure 15N–13C dipole-dipole NMR spectra in static liquid crystalline samples with natural abundance is introduced. We demonstrate that well-resolved spectra can be recorded within 10 h of experimental time using a conventional NMR probe and a moderately strong magnetic field. The technique is applied to a thermotropic smectic mesophase formed by an ionic liquid with imidazolium-based organic cation. 相似文献