The motion of an electron in graphene in a magnetic field in the presence of an external electromagnetic wave of circular polarization is studied. Electron in graphene has linear momentum energy spectrum corresponding to the dispersion law for massless quasiparticles. The solution corresponding to cyclotron resonance when a frequency of radiation coincides with a `` cyclotron frequency '' of quasiparticles in the absence electromagnetic wave is obtained in the limit of a weak field. Since a rotational frequency of massless quasiparticles in magnetic field depends on its energy a cyclotron resonance line turns out to be very broad. For the special case, where the frequency of radiation is twice the `` cyclotron '' frequency, the exact solution of the equation of motion of quasiparticle in a magnetic field and field of the wave is obtained. Thus in this case in terms of describing the electron motion we obtain a kind of the wave frequency halving in a magnetic field.
Show AbstractThe paper presents a general harmonic solution of Maxwell's electrodynamics equations with a dilaton in the stationary case. One of the presented classes of solutions describes the field of a dione with a nontrivial dilaton charge. It is shown that for a harmonic solution of the Coulomb type, the magnetic field is purely Coulomb, whereas the electric and dilaton fields can be distributed in space in a complex way.
Show AbstractCriteria are analyzed for the selection of gamma-ray showers against the background of proton showers. The mechanism of criterion functioning is described in the primary energy range 30-100 TeV. The basis of a criterion capable of separating the two classes of events is formed by the integrals of the optical cascade curve over the characteristic altitude ranges which are obtained through the measured angular distribution of Cherenkov light of an extensive air shower. The conducted analysis gives way to further improvements of criteria for Cherenkov gamma-ray astronomy and the study of mass composition of the primary cosmic rays.
Show AbstractThere were studies the radiation resistance of organic plastic scintillators UPS-923A, SCSN-81, SC-301 and SC-307 based on polystyrene, and scintillators BC-408 and EJ-260 based on polyvinyl toluene. There were also studied properties of irradiated Tyvek and ESR reflectors; Paint + TiO2, PMS + TiO2 and Epoxy + TiO2 coatings. The results of this work are aimed at the creating of a radiation-resistant CMS Hadron Endcap Calorimeter at the Large Hadron Collider. The CMS detector is currently being upgraded to study the Higgs boson under the high luminosity conditions.
Show AbstractThe observed properties of the low-lying collective excitations of $^{96}$Zr and $^{96}$Mo are investigated in the framework of the collective quadrupole nuclear model with the Bohr Hamiltonian, whose potential energy has two minima – spherical and deformed. Satisfactory description of the excitation energies and transition probabilities is obtained. It is shown that in the case of $^{96}$Zr both minima are sufficiently deep. However, in the case of $^{96}$Mo a deformed minimum is only outlined.
Show AbstractThe article discusses the results of the development of a one-dimensional disk mathematical model of the electrodynamic system of a multi-beam klystron, taking into account the non-identical conditions for the interaction of electron beams with the fields of ring resonators. An equivalent circuit of a ring resonator operating on the highest form of oscillations is presented, based on the equations of electromagnetic wave propagation in a waveguide with losses and adequately tracking the amplitude and phase unevenness of the microwave field in the ring gaps of the resonator interaction. The unevenness of the field in the interaction gap can be caused by the influence of communication elements with the load, unequally grouped electron beams and other factors.
Show AbstractThe necessity for long-term forecast of proton fluxes in near-Earth space is explained by the need to ensure the safety of space missions. In the article the data on proton fluxes outside the Earth's magnetosphere for 1972-2018, obtained on board IMP and GOES series is analyzed. The dependences of the average annual proton fluxes (for energies > 1 MeV, > 2 MeV, > 4 MeV, > 10 MeV, > 30 MeV, > 60 MeV) and their standard deviations from the Wolf numbers were revealed, and the pattern of distribution of proton fluxes was derived. The constructed probability distribution functions of the average annual proton fluxes for given values of the Wolf numbers allow us to estimate the probability that the average annual value of proton fluxes will not exceed a certain value for integer Wolf number.
Show AbstractPoisson distribution is derived from gamma-distribution. The passage to the limit for sufficiently large values of parameter to normal distribution is proved without using Stirling's formula. Results are illustrated on the example of Brownian particle motion.
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