Том 54, № 3 (2019)

The results to increase the rated energy of the linear accelerator of electrons LUE-75 from 50 to 75 MeV are presented. The characteristics of the beam are investigated, and the measured energy spectra of the obtained beams are presented in the range of 50–75 MeV at the average intensity up to 10 μA. The modernization of the elements of magnetic optics for the parallel transfer path was performed, and the beam was tracked to the end of the transport channel.

The scattering of a quantum particle (an electron) on a chain of N non-overlapping identical and periodically located 5-shaped two-dimensional scattering centers is considered. When taking into account the transverse dimensions of the chain, this scattering is a multi-channel. The asymptotic value of an impedance of the chain is estimated when N tends to infinity. It is shown that the results a two dimensionality of motion of particle at a one-channel scattering coincide with the results of one-dimensional theory of scattering. Only the shift of the boundaries of the energy gap occurs. The picture is radically changing in the case of multichannel scattering: the impedance of the chain tends to infinity when N→ ∞. This means that in the 2D periodic conduction system with the nanometer widths the localization of the single-particle quantum states of an electron is possible. This result does not depend on the energy of the incident particle.

A theory of a broadband thin-film polarizing beam splitter based on an anisotropic cycloidal diffraction grating is proposed. The achromatization of the grating is provided by creating two-layer chiral structures with an opposite twist sense. Such a system has almost 100% efficiency. The calculations were carried out by the Jones matrix method. The resulting efficiency and bandwidth are higher than the previously known results.

The influence of dimensional quantization on the process of self-induced transparency in the system of spherical quantum dots in the frames of the model of the simplest interband transition in the symmetrical spherical infinitely deep wall is considered. Expressions describing the evolution of the energy of ultraviolet pulses are obtained. The relative energy losses when it becomes the 2π-pulse during propagation in a nanoscale medium, and also the polarization of the medium of non-homogeneous broadening, caused by the dispersion of radius of spherical quantum dots are obtained. The case when the radial distribution is described by the Lifshitz-Slyozov formula is considered.

Based on the technology developed by authors of the local diffusion doping of certain parts of the ZnO film of the donor (Ga) and acceptor (Li) impurities, a transparent field-effect transistor with the n-type channel was manufactured. The MgF2 films were used as a gate insulator. The field effect and the dark electrical characteristics of the structures were investigated. The field phototransistors based on these structures have been developed. The photoelectric characteristics of the field phototransistors were investigated, and the mechanism of the photoelectric amplification was proposed.

In this paper, by an analogy with the 3D-systems, and because of the analysis of the dimensionalities of the variables involved, an expression is derived in the quasi-harmonic approximation that allows one to estimate the linear thermal expansion coefficient for a single-layered graphene (which represents the 2D-system) at the temperatures close to the room temperature. It is shown that compared to the other methods to evaluate the thermal expansion coefficient of graphene at the room temperatures (the molecular dynamics method or the method of approximation with the aid of nonequilibrium Green’s function, for which the obtained results differ from experimentally measured values at least by 7%), the accuracy of the value obtained by the suggested expression is 5 times higher (the discrepancy from the measured values figures up to 1.4%).

One of the interesting problems is the determination of the phase position and phase jitter of electron bunches in the field of an accelerating electromagnetic wave. It is shown that the phase position and phase jitter of the cosine segment is possible to determine by the phase spectrum in the microwave range.

The mathematical, formal-kinetic description of the diffusion nature of observed dimensional shifts in erythrocytes (the swelling and shrinkage) at early post-radiation period is proposed, and the quasi-chemical model of the diffusion diode is constructed for the transfer processes of micro-particles (including the water molecules) through biological membranes.