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Vol 43, No 1 (2016)
- Year: 2016
- Articles: 11
- URL: https://journals.rcsi.science/1068-3356/issue/view/14047
Article
Cosmological consequences of the particle-antiparticle gravitational repulsion hypothesis: the Newtonian model of the universe
Abstract
The model of the gravitationally neutral Universe (GNU), i.e., a giant but finite 3D Ball expanding in the infinite static Euclidean space, is considered. The model is based on the antigravitation between particles and antiparticles. The GNU Ball is filled equally by matter and antimatter clusters and freely expands after epochs of partial annihilation and recombination. The abandonment of the cosmological principle and the problem of our Galaxy position in the GNU Ball are discussed.
1-4
Structure and magnetic properties of layers formed by laser fusing of powders on nonmagnetic substrates
Abstract
Studies of the structure and magnetic properties of layers formed on nonmagnetic substrates by laser powder fusing (LPF) showed that crystalline phases are separated from initial powders of bronze, inconel (IN 625), and PGSR-4with the transformation of nonmagnetic materials to soft ferromagnets. The fused bronze powder layer exhibits soft ferromagnetic properties with two types of magnetic domains with the Curie temperatures of 80 and 300 K and a coercivity to 90 Oe at 300 K; in layers based on In625 and PGSR-4, only one type of magnetic domains with the Curie temperatures of 260–270 K is formed, which provides soft ferromagnetic properties at 4 К and the paramagnetic transition at 300 K.
5-7
Ballistic transfer of spin momentum in multiferroic tunnel junction
Abstract
The field dependence of critical voltages of switching of magnetic states of a synthetic multiferroic structure is studied based on a bifurcation analysis of Landau–Lifshitz–Gilbert equations with the torques caused by a tunneling spin transport, taking into account the voltage dependence of transferred spin momenta at the variations in the magnitude and direction of electric polarization. The voltage dependences of transferred spin momenta are determined based on the free electron model, taking into account exchange splitting of electron energy subbands in magnetic beaches and the effect of changing the tunnel barrier height at the variations in the polarization magnitude and state.
8-11
On the theory of nonlinear Thomson scattering of a highly focused laser pulse
Abstract
The problem of nonlinear Thomson scattering of an ultrashort laser pulse on free electrons from a sharp focus is solved within the test particle approach. To describe the laser beam fields, an exact solution to the Helmholtz equation is used, which allows simulation of the electron dynamics and emission when the paraxial approximation is certainly inapplicable. Characteristics of attosecond electromagnetic pulses of secondary emission from test electrons during their motion near the laser focus are studied.
12-15
Nonlinear plasma resonance in inhomogeneous relativistic plasma
Abstract
We present a theoretical study of relativistic electron plasma oscillations in the plasma resonance region based on the renormalization group symmetry method. A steady-state solution to equations describing the electron dynamics in the vicinity of the plasma resonance is found and spatial-temporal and spectral characteristics of the potential electric field are discussed.
16-19
Incomplete ozone recovery effect in the presence of active oxygen species
Abstract
The degree of ozone recovery after pulsed UV laser photolysis of O2-O3-Ar mixture is measured using time-resolved absorption spectroscopy. The effect of incomplete ozone recovery in the presence of molecular singlet oxygen O2(a1Δ) and atomic oxygen is detected. This effect is caused by the reaction between the vibrationally excited ozone molecule formed due to recombination and atomic oxygen. The branching factor for the chemical channel of reaction products is γr = 0.81 ± 0.13.
20-25
Theory of turbulent heating of current DT plasma
Abstract
The theory of turbulent heating in the mode of hot deuterium ions and cold tritium ions is developed for plasma with equal deuterium and tritium ion concentrations. The possibility of heating electrons and deuterium ions by thousands of times is shown.
26-34
Adaptive photodetectors based on charge gratings in the problems of frequency-modulated optical signal detection
Abstract
Nonstationary photovoltage excitation by frequency-modulated light in an adaptive photodetector based on GaAs is studied. To observe the effect, the crystal is exposed to light beams with the relative frequency shift Δf(t). Linear frequency modulation Δf(t) = At is used in the experiments. As a result of such illumination, a pulsed electrical signal is induced in the crystal. The pulse appears at the deceleration of the interference pattern motion, and its duration is controlled by the frequency variation rate A and the time of the charge grating formation. The possibility of using the effect in the systems for measuring velocities and accelerations of moving objects is shown.
35-36
On the effect of boundary conditions on I–V characteristics of HTSC tunnel junctions
Abstract
The pairing potential distribution over the thickness of superconducting CuO2 layers in cuprate HTSCs is determined within the Ginzburg–Landau (GL) theory using the microscopic justification of this theory by Gor’kov. It is found that the pairing potential in them is significantly suppressed due to the effect of non-superconducting interlayers, which results in a decrease in the critical temperature of these superconductors. The temperature dependences of the effective energy gap and current–voltage (I–V) characteristic of tunnel junctions of the “break junction” type made of these superconductors are calculated.
37-42
Dosimetry problem in the case of accidental combined irradiation and its possible solution by the example of the consideration of the effect of a number of radiation factors during the Chernobyl accident
Abstract
The paper is devoted to the radiation monitoring problem under conditions of accidental multifactorial irradiation during nuclear reactor accidents, including real-time monitoring. An algorithm of the corrections for the contributions to the effective equivalent dose (in addition to the main (gamma) irradiation) of the external beta irradiation and internal irradiation of incorporated iodine-131 decay is proposed.
43-48
Notes on electromagnetic waves in a medium with negative ε and μ. II
Abstract
The consideration of the problem of the possible existence of homogeneous isotropic media with simultaneously negative permittivities and permeabilities is continued. It is shown that the previous negative answer is also retained in the case of a more rigorous consideration of frequency dispersion. As a matter of discussion, it is proposed to somewhat change the system of Maxwell equations in a dispersing medium.
49-51