Technical Physics Letters

Barabin, S. V.; Kropachev, G. N.; Lukashin, A. Yu.; Kulevoy, T. V.; Vybin, S. S.; Golubev, S. V.; Izotov, I. V.; Kiseleva, E. M.; Skalyga, V. A.; Grigoriev, S. V.; Kovalenko, N. A.

doi: 10.1134/s1063785021050199pmid: N/A

The advantages of using a gasdynamic proton source based on electron cyclotron resonance in a compact neutron source with a proton accelerator of the DARIA project are discussed. A gasdynamic source of protons has been shown to provide a beam with a current of ~100 mA and a duration more than 100 μs at a repetition rate up to 1000 pulse/s. Using the “pepper-pot” method, measurements of the emittance have been performed of a beam generated by a gasdynamic source of electron cyclotron resonance with two geometric configurations of electrodes forming the beam: “spherical” and plane-parallel. It is shown that the normalized 4-rms emittance for both variants of the beam-formation system electrodes in the extraction voltage ranges from 41 to 48 kV and does not exceed 2π mm mrad.

Dmitriev, A. I.; Kochura, A. V.; Marenkin, S. F.; Lähderanta, E.; Kuz’menko, A. P.; Aronzon, B. A.

doi: 10.1134/s1063785021050205pmid: N/A

Magnetic anisotropy of needlelike single-crystal MnSb inclusions in an InSb matrix has been identified and investigated in the temperature range of 5–350 K. A power-law dependence of anisotropy constant K(T) on saturation magnetization MS(T) is observed in granular InSb–MnSb samples in the temperature range of 5–350 K with exponent n = 3.2 ± 0.4 in correspondence with the theories developed by Akulov, Zener, and the Callens.

Efremova, E. V.; Kuzmin, L. V.

doi: 10.1134/s1063785021050217pmid: N/A

A technique for increasing the accuracy of ranging with the use of ultrawideband chaotic radio pulses is proposed for using in wireless sensor networks. As a result of performed experimental bench tests, it is shown that the level of the relative ranging error falls inside the limits of 5–9%.

Ekomasov, E. G.; Nazarov, V. N.; Samsonov, K. Yu.; Murtazin, R. R.

doi: 10.1134/s1063785021050229pmid: N/A

Generation and excitation of a magnetic soliton in a three-layer ferromagnet using dc magnetic fields and weak ac fields in the presence of dissipation in the system have been considered. An analysis of the solutions to the equation of motion in an ac field shows the possibility of increasing the magnetic-soliton amplitude with time under certain conditions. The resonance effect is also affected by the geometric parameters of the thin layer: the translational mode of soliton oscillations is excited at a large layer width.

Il’ichev, E. A.; Kuleshov, A. E.; Petrukhin, G. N.; Minakov, P. V.; Rychkov, G. S.; Sen’, V. V.; Teverovskaya, E. G.

doi: 10.1134/s1063785021050230pmid: N/A

The use of diamond photocathodes and electron flow multipliers in high-frequency vacuum micro- and nanoelectronics is discussed. Vacuum microtriode (microtube) and electron gun for integrated travelling-wave tube amplifiers are considered as the main devices of this kind.

Megela, I. G.; Maslyuk, V. T.; Roman, I. Yu.; Pop, O. M.; Vieru-Vasilitsa, T. O.

doi: 10.1134/s1063785021050242pmid: N/A

We have studied the luminescent properties of MgO ⋅ 2.5Al2O3 nonstoichiometric spinel irradiated in direct and scattered beams by 12-MeV electrons accelerated in an M-30 microtron. It is established that the kinetics of irradiation-induced phosphorescence decay is described by the Beckuerel hyperbola with an exponent increasing with the electron fluence. The laws of thermoluminescence peak variation in 110—250°C temperature interval were also studied depending on the irradiation dose. It is concluded that the behavior of this peak can be used for clinical and technological diagnostics of pulsed electron beams.

Men’shakov, A. I.; Emlin, D. R.

doi: 10.1134/s1063785021050254pmid: N/A

We propose a method for obtaining TiN coatings by reactive anodic evaporation of titanium using a high-current (30 A) discharge with a self-heated hollow cathode in an Ar + N2 gas mixture. The optical spectral analysis shows that the gas-discharge plasma contains a large amount of activated titanium, while the fraction of singly charged metal ions supplied from the plasma to substrate reaches up to 70%. Titanium coatings with 2-μm thickness and up to 24-GPa hardness were obtained at a nitrogen flow rate of 5 cm3/min. The rate of TiN deposition at a distance of 7 cm from the vapor source amounted to ~4 μm/h.

Proskuryakov, V. I.; Rodionov, I. V.

doi: 10.1134/s1063785021050266pmid: N/A

An experimental study of the laser modification of the surface of 12Kh18N10T stainless steel in a layer of graphite paste and nanodispersed titanium dioxide powder (anatase) has been performed. It is found that a microheterogeneous modifying layer is formed on the surface of the samples as a result of pulsed laser treatment. The surface is characterized by increased microhardness and microroughness parameters, which largely depend on the pulse voltage. The formation of fine particles with sizes ranging from 100 to 300 nm is observed in the diffusion layer of the specimens.

Rudinskii, A. V.; Yagodnikov, D. A.; Ryzhkov, S. V.; Onufriev, V. V.

doi: 10.1134/s1063785021050278pmid: N/A

A mathematical model of oxygen–methane plasma combustion at pressures of 0.2−1.6 MPa has been developed with allowance for the ionization of combustion products and recombination of charged components. Positive ion concentrations in characteristic zones of the reacting oxygen–methane mixture are estimated under the assumption of ambivalent diffusion. Distributions of self-consistent electric field and generated electric charge along the channel are determined. Results of modeling of the levels of electron and ion concentrations in the flame agree with the well-known experimental data obtained by probe methods under operation conditions of a model liquid-propellant rocket engine.

Ryzhkov, V. A.; Tarbokov, V. A.; Smolyanskii, E. A.; Remnev, G. E.

doi: 10.1134/s106378502105028xpmid: N/A

A combination of two methods (nondestructive proton beam radioactivation analysis and optical microinterferometry) has been used for measuring the mass and linear thicknesses of AlN and CrN coatings deposited onto silicon substrates by means of magnetron sputtering. It is established that, at linear thickness from 2.2 to 5.7 μm, the density of deposits is close to that of bulk materials (3.26 g/cm3 for AlN and 5.9 g/cm3 for CrN), while the stoichiometry of nitrides can be controlled by varying the parameters of magnetron sputtering. The proposed method can also be used for determining the densities of metal carbide and oxide films used as wear-resistant coatings.