The injection of a plasma bunch into a multipolar trap can be applied to fill the trap with a plasma. The injection of the bunch into a tokamak-like trap can be considered an additional means for controlling the processes of plasma heating and fuel delivery to the central zone of a thermonuclear reactor. In both cases, the bunch is injected normally to the magnetic field of the trap. It has been shown theoretically, experimentally, and by numerical simulation that the depth of plasma bunch penetration into the magnetic field varies in direct proportion to the bunch energy and in inverse proportion to the magnetic pressure and the cross-sectional area of the plasma bunch. The data of this work allow researchers to estimate the values of plasma bunch parameters at which the bunch will be trapped. As a result, the process of plasma bunch trapping has been optimized.

Поступило в Редакцию 26 апреля 2017 г

The third-order susceptibility of vinylidene fluoride-trifluoroethylene (VDF-TrFE) copolymer are analyzed by using the z-scan technique with a nanosecond laser as an excitation source. It is established that optical transmittance of the VDF-TrFE samples decreases after their polarization in an electric field.

The properties of short-circuited multiturn superconducting coils have been studied; coils with nonsuperconducting contacts have been fabricated from a high-temperature superconducting (HTSC) tape made by Super Power Company. The magnetic flux captured by HTSC coils has been measured at different values of magnetic field of the magnetizing solenoid. the critical current in the coils have been experimentally determined based on the maximum values of the field they captured. It is ~50% of the nominal value for this HTSC tape. The range of external magnetic field, where HTSC coils keep the captured magnetic flux, has been experimentally found. The obtained results have demonstrated the possibility of designing magnet systems with levitating coils made of HTSC tape, in which levitation is controlled without using feedbacks.

The photovoltaic properties and the bulk photovoltaic effect have been studied in a polyvinylidene difluoride–trifluoroethylene polymeric ferroelectric doped by single-walled nanotubes and a ruthenium-based dye. The dopants serve as spectral sensibilizers that improve sensitivity to 532-nm laser radiation.

Composites with photoelectrical, nonlinear optical, and photorefractive properties have been prepared. The composites consist of polyvinyl alcohol, single-wall carbon nanotubes, and fullerene C-60. Addition of C-60 with a long wavelength boundary near 630 nm resulted in an eight- to tenfold increase in both the quantum efficiency of generation of mobile hole charges and the photorefractive two beam gain coefficient measured at wavelengths exceeding 1000 nm (over an area of optical absorption of nanotubes). This is attributed to electron trapping by acceptor fullerene, which limits the regeneration of photogenerated charges and provides an increase in mobile hole charges.

The interaction of solitary waves in a model of two-fluid MHD is studied analytically and numerically, with the inertia of electrons being systematically taken into account. We consider waves in linearly polarized magnetic field. The distinctive feature of this work is the use of “exact” equations rather than an approximate approach (model equation). It is shown numerically that solitary waves are indeed solitons, i.e., their interaction is similar to that of colliding particles.

Products of thermal cracking of kerogen of Lower-Middle Cambrian oil shale are studied by modern instrumental analytical methods (FTIR, gas chromatography, mass spectrometry, etc.). The analyses demonstrate that the geopolymer kerogen matrix inherited fragments of lipids synthesized by living organisms, including aliphatic fat acids, both free or bounded into glycerol esters, i.e., animal or vegetable fats. It is shown that vegetable pigments (carotenes and xanthophylls) play a crucial role in the formation of monocyclic structures (including molecular alkylbenzene, alkylphenol, and phenylalkane fragments) in kerogen. Since the studied kerogen is rich in esters, it is worth performing alkaline hydrolysis of its macromolecules (ester saponification) before their thermolysis, which inevitably distorts the initial structure of molecular skeletons. (C) 2015, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.

In order to develop a plasma trap with levitating superconducting magnetic coils, it is necessary to search for their stable levitating states. An analytical expression for the potential energy of a single superconducting ring that captures a fixed magnetic flux in the field of a fixed ring with constant current versus the coordinate of the free ring on the axis of the system, deviation angle of its axis from the axis of the system, and radial displacement of its plane is derived for uniform gravity field in the thin ring approximation. The calculated stable levitation states of the superconducting ring in the field of the ring with constant current are proven in experiments. The generalization of such an approach to the levitation of several rings makes it possible to search for stable levitation states of several coils that form a magnetic system of a multipole trap.

Measurement of the photoelectric and photorefractive characteristics of 2,3,9,10,16,17,23,24-tetra(15-crown-5)phthalocyaninatoacetatoyttrium(III) [(15C5)4Pc]Y(OAc) has made it possible to reliably establish the features of decrease in the quantum yield of generation of charge carriers φ0 and photorefractive two-beam coupling gain Γ with an increase in the atomic weight of the central metal in a series of related gallium(III), yttrium(III), ruthenium(II), and indium (III) phthalocyaninates. These features can be due to an increase in the spin-orbit interaction constant with increasing atomic weight of the central metal, a change that leads to an increase in both the contribution of triplet excited associates to the formation of mobile charge carriers and the rate of the reverse reaction T 1 → S 0, which effectively inhibits the formation of charge carriers through the excited triplet state. The measurement of photoelectric and photorefractive characteristics at 1064 nm has shown that the quantum yield of electron-hole pairs in the composite polyvinylcarbazole/supramolecular assemblies of yttrium complex is φ0 = 0.6 and the two-beam coupling gain coefficient Γ is about 35 cm−1 at E 0 = 120 V/μm. The dielectric susceptibility measured by the z-scan technique in a solution of the yttrium complex in tetrachloroethane (1 mg in 1 mL) is χ(3) = 4.2 × 10−10 esu.

We consider the possibility of designing a plasma trap with a magnetic system formed by super-conducting rings and coils levitating in the field of a fixed coaxial coil carrying constant current. An analytic dependence of the potential energy of such a system with one or two levitating superconducting rings having trapped preset magnetic fluxes on their coordinates in the uniform gravitational field is obtained in the thin ring approximation. Calculations performed in the Mathcad system show that equilibrium states of such a system exist for certain values of parameters. Levitating states of a single superconducting ring and two superconducting rings in the field of the coil with constant current are observed experimentally in positions corresponding to calculated values.

The photorefractive effect is demonstrated for the first time for the composite consisting of a ferroelectric material (polyvinylidenefluoride-trifluoroethylene) and single-walled carbon nanotubes that serve as nonlinear optical chromophores and, simultaneously, spectral sensitizers for the laser radiation with a wavelength of 1064 nm. It is demonstrated that the internal field in the ferroelectric material makes it possible to measure the photorefractive effect in the absence of the external field.