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1.
The data obtained on the ACTIVE, SAMPEX, and TIROS-N satellites are used to study the dynamics of low-energy (from tens of keV to several MeV) proton fluxes in the region of the geomagnetic equator (L < 1.15) at low altitudes (up to 1000 km). The dependence of the fluxes on the local magnetic time is presented. A number of magnetic disturbances in November–December 1978 are analyzed to illustrate the dependence of the flux on the geomagnetic activity level. The results obtained allow the conclusion that the ring current is one of the main sources of protons at low altitudes in near-equatorial latitudes. 相似文献
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V. S. Makhmutov L. Desorgher G. A. Bazilevskaya E. Flückiger 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(7):950-952
The method for evaluating the energy spectra of solar protons at the boundary of the Earth’s atmosphere according to the data of balloon measurements carried out at the Lebedev Institute of Physics, Russian Academy of Sciences, and the results of Monte Carlo simulation of the processes of proton interaction in the Earth’s atmosphere has been developed. The balloon measurements during solar proton events make it possible to determine the absorption spectra of solar cosmic rays in the atmosphere. Comparison of the experimental data with the results of the simulation of propagation of solar protons (E p = 10 MeV-10 GeV) in the atmosphere, based on GEANT-4, allows determination of the energy spectra of solar protons at the atmospheric boundary. The results of the determination of the energy spectra of solar protons in a number of solar proton events in the current (23th) solar activity cycle are reported. 相似文献
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A. G. Bogdanov R. P. Kokoulin Yu. F. Novoseltsev R. V. Novoseltseva V. B. Petkov A. A. Petrukhin 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(3):411-413
The energy spectrum of cosmic ray muons in the range of several TeV to PeV obtained through the analysis of multiple interactions
of muons (the pair meter technique) in the Baksan Underground Scintillation Telescope (BUST) is presented. Results are compared
with prior BUST data on the muon energy spectrum measurements and data of other experiments, along with calculations for different
muon spectrum models. 相似文献
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Energy spectrum of cosmic protons and helium nuclei by ahybrid measurement at 4300 m a.s.l. 下载免费PDF全文
The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured below the so-called "knee" by using a hybrid experiment with a wide field-of-view Cherenkov telescope and the Resistive Plate Chamber (RPC) array of the ARGO-YBJ experiment at 4300 m above sea level. The Hydrogen and Helium nuclei have been well separated from other cosmic ray components by using a multi-parameter technique. A highly uniform energy resolution of about 25% is achieved throughout the whole energy range (100-700 TeV). The observed energy spectrum is compatible with a single power law with index γ=-2.63±0.06. 相似文献
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The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured below the so-called "knee" by using a hybrid experiment with a wide field-of-view Cherenkov telescope and the Resistive Plate Chamber(RPC) array of the ARGO-YBJ experiment at 4300 m above sea level. The Hydrogen and Helium nuclei have been well separated from other cosmic ray components by using a multi-parameter technique. A highly uniform energy resolution of about 25% is achieved throughout the whole energy range(100–700 TeV). The observed energy spectrum is compatible with a single power law with index γ =-2.63±0.06. 相似文献
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Marklund GT Sadeghi S Karlsson T Lindqvist PA Nilsson H Forsyth C Fazakerley A Lucek EA Pickett J 《Physical review letters》2011,106(5):055002
Aurora, commonly seen in the polar sky, is a ubiquitous phenomenon occurring on Earth and other solar system planets. The colorful emissions are caused by electron beams hitting the upper atmosphere, after being accelerated by quasistatic electric fields at 1-2 R(E) altitudes, or by wave electric fields. Although aurora was studied by many past satellite missions, Cluster is the first to explore the auroral acceleration region with multiprobes. Here, Cluster data are used to determine the acceleration potential above the aurora and to address its stability in space and time. The derived potential comprises two upper, broad U-shaped potentials and a narrower S-shaped potential below, and is stable on a 5 min time scale. The scale size of the electric field relative to that of the current is shown to depend strongly on altitude within the acceleration region. To reveal these features was possible only by combining data from the two satellites. 相似文献
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The purpose of our study is to understand the mathematical origin in real space of modulated and damped sinusoidal peaks observed in cosmic microwave background radiation anisotropies. We use the theory of the Fourier transform to connect localized features of the two-point correlation function in real space to oscillations in the power spectrum. We also illustrate analytically and by means of Monte Carlo simulations the angular correlation function for distributions of filled disks with fixed or variable radii capable of generating oscillations in the power spectrum. While the power spectrum shows repeated information in the form of multiple peaks and oscillations, the angular correlation function offers a more compact presentation that condenses all the information of the multiple peaks into a localized real space feature. We have seen that oscillations in the power spectrum arise when there is a discontinuity in a given derivative of the angular correlation function at a given angular distance. These kinds of discontinuities do not need to be abrupt in an infinitesimal range of angular distances but may also be smooth, and can be generated by simply distributing excesses of antenna temperature in filled disks of fixed or variable radii on the sky, provided that there is a non-null minimum radius and/or the maximum radius is constrained. 相似文献
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V. S. Puchkov A. S. Borisov Z. M. Guseva V. G. Denisova E. A. Kanevskaya M. G. Kogan V. M. Maximenko A. E. Morozov R. A. Mukhamedshin S. E. Pyatovsky M. D. Smirnova 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(3):392-394
Adjusted data on the fraction of protons in the mass composition of primary cosmic rays (PCRs) in the energy range of 1015–1017 eV are presented. Adjustments are made according to detailed calculations of the response of the X-ray emulsion chamber in the PAMIR experiment. It is demonstrated that the fraction of protons in a PCR is 16–18% for E 0 ≈ 1015–1016 eV and does not change within the error for E 0 ≈ 1016–1017 eV. 相似文献
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Some distinctive features in the behavior of small-scale artificial ionospheric irregularities at mid-and high latitudes 总被引:1,自引:0,他引:1
N. F. Blagoveshchenskaya T. D. Borisova V. A. Kornienko V. L. Frolov M. T. Rietveld A. Brekke 《Radiophysics and Quantum Electronics》2007,50(8):619-632
We present the results of experimental studies of some features in the behavior of small-scale artificial irregularities (SSAIs)
at mid-and high latitudes based on the “Sura” and EISCAT/HEATING HF facilities. Observations were performed by the method
of aspect scattering using a network of diagnostic paths having a common reception point located near St. Petersburg. We found
that an extremely long duration of the second (slow) stage of SSAI relaxation of up to 5 min occurs in the evening hours when
the ionosphere above the “Sura” facility is illuminated by the Sun, but the solar terminator travels through the magnetically
conjugated ionosphere. The conjecture is made that the processes initiated by the terminator are mostly responsible for secondary
ionospheric turbulence maintaining the irregularities above “Sura.” A drastic increase in the Doppler spectra width of the
scattered signals is revealed when the magnetically conjugate point of the ionosphere is located on the shade side of the
terminator, but the ionosphere above the “Sura” facility is still lighted. It is assumed that the “ run away” of photoelectrons
from the day to the night side could reduce the threshold of excitation of artificial irregularities, leading to an increase
in their intensity. The presence of fairly intense scattered signals was detected from the “Sura” and EISCAT/HEATING experimental
results both under conditions of pulsed HF heating after continuous heater-on periods and cycled HF heating by short pulses.
In the case of pulsed heating by short pulses with duration τp < 100 ms and average radiated power Pa below the threshold power Pthr of the SSAI generation cutoff the irregularities can be maintained due only to striction parametric instabilities. The excitation
of irregularites under the cycled HF pumping with the pulse duration τp = 384 ms for Pa comparable with Pthr was detected. The aspect-angle dependence, or the so-called magnetic zenith effect, was found in the SSAI intensity. The
residual turbulence aftereffects played a significant role in the SSAI development.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 50, No. 8, pp. 678–694, August 2007. 相似文献
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A. K. Managadze R. A. Mukhamedshin 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(11):1315-1318
Experimental and calculation data on γ-ray-hadron families, obtained using X-ray emulsion chambers at superhigh energies (E 0 ? 1015 eV) in stratospheric and high-mountain investigations of cosmic rays, are discussed. Relations between model characteristics and experimental data on the transverse size and alignment of the most energetic subcores in γ-h families are considered. Lateral characteristics of γ-ray families are shown to be independent of secondary particles 〈p t 〉 in h-A interactions but are strongly determined by the p t (x Lab) dependence at 0.05 ? x Lab ? 0.20. Conclusions on properties of h-A interactions at superhigh energies are drawn. 相似文献
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V. G. Gavrilyachenko Yu. V. Kabirov E. M. Panchenko E. I. Sitalo T. V. Gavrilyachenko E. V. Milov N. V. Lyanguzov 《Physics of the Solid State》2013,55(8):1651-1654
The dielectric spectra of CaCu3Ti4O12 ceramics with giant values of the dielectric constant have been presented. The spectrum exhibits Debye dispersion with an activation energy of 0.075 eV in the high-frequency range of 106–107 Hz, and a characteristic plateau has been seen in the frequency dependence of the dielectric constant in the range of 104–105 Hz. A considerable increase in the loss factor ?″ has been observed in the low-frequency part of the spectrum and a capacitive-to-inductive impedance transition has been revealed in some samples at a frequency below 10?2 Hz. The causes of this transition have been discussed. 相似文献
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Application of the Tikhonov regularization method to wind retrieval from scatterometer data I. Sensitivity analysis and simulation experiments 下载免费PDF全文
Scatterometer is an instrument which provides all-day and large-scale wind field information, and its application especially to wind retrieval always attracts meteorologists. Certain reasons cause large direction error, so it is important to find where the error mainly comes. Does it mainly result from the background field, the normalized radar cross-section (NRCS) or the method of wind retrieval? It is valuable to research. First, depending on SDP2.0, the simulated `true' NRCS is calculated from the simulated 'true' wind through the geophysical model function NSCAT2. The simulated background field is configured by adding a noise to the simulated 'true' wind with the non-divergence constraint. Also, the simulated 'measured' NRCS is formed by adding a noise to the simulated 'true' NRCS. Then, the sensitivity experiments are taken, and the new method of regularization is used to improve the ambiguity removal with simulation experiments. The results show that the accuracy of wind retrieval is more sensitive to the noise in the background than in the measured NRCS; compared with the two-dimensional variational (2DVAR) ambiguity removal method, the accuracy of wind retrieval can be improved with the new method of Tikhonov regularization through choosing an appropriate regularization parameter, especially for the case of large error in the background. The work will provide important information and a new method for the wind retrieval with real data. 相似文献
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The emission of a low-pressure helium plasma (P≤2 Torr) initiated by a monochromatic electron beam is investigated. It is found that an increase in the current leads to a drastic increase in the rate of charge exchange of doubly charged helium ions. The assumption is made that inelastic collisions of He++ ions with metastable helium atoms provide the main channel of charge exchange of these ions due to the reaction He+++Hem→ He+*+He 0 + . 相似文献
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V. I. Yakovleva V. E. Yakhontova A. B. Tsyganov I. E. Kozlov 《Optics and Spectroscopy》2003,95(3):333-335
The population kinetics of the energy levels of atoms excited in a tube with an electron beam is studied. A method of separating the contributions made by direct electron impact and by secondary processes to the population of the levels considered is proposed. 相似文献
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I. A. Yung R. A. Pantina D. V. Lebedev M. V. Filatov V. V. Isaev-Ivanov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2013,7(6):1137-1142
The distribution of replication origins in the nuclei of different cells is studied by confocal microscopy. Based on the obtained images, three-dimensional maps of the positions of the origin centers is constructed and the distribution functions of the pair distances between them are calculated. It is established that the distance distribution function for HeLa and glioma human cells is linear at sizes up to 2 μm, which indicates that the size of the origin system is close to 2. The amplitude of the distance distribution function at small sizes has a power dependence on the nucleus size and is inversely proportional to the nucleus volume to the power of 0.9. Thus, the replication-origin distribution in a nucleus cannot be described by a model with a single Hausdorff dimension in the whole range of sizes. 相似文献