Results of an experimental study of the oxygen permeability of a PET film with nanosized aluminum oxide layers formed by reactive magnetron sputtering have been described. An experimental dependence of the oxygen permeability coefficient of PET film with the aluminum oxide layer in the range of 20 ÷ 80 nm, providing its value up to 1 cm3/(m2∙24h∙0.1MPa), have been determined. The effect of various factors on the formation of a high-quality reproducible oxide PET film and the characteristics of a nanosized aluminum oxide layer and the specific electric energy consumption for the magnetron deposition of the layer has been defined. The planar surface structures and surface roughness parameters of PET and oxide films with layers of different thicknesses have been determined. A qualitative interpretation of the results has been given.

The paper introduces the development of the technology of reactive magnetron deposition of a nanosized aluminum oxide layer on a roll PET film, which provides a low specific permeability relative to oxygen. We describe a large-size magnetron deposition facility and its optimal operating modes, as well as the sequence of operations performed. Within the research, we found that various parameters of magnetron deposition of aluminum oxide affect the characteristics of the nanosized layer. The thicknesses of oxide layers were measured in the range of 20--80 nm, the roughness of their surfaces and their structures and reliefs were estimated. Furthermore, we established the experimental dependence of the specific permeability relative to the oxygen of the oxide layer on the PET substrate on its thickness in the range of 20--80 nm. The study gives its qualitative explanation and describes the specific energy consumption

The results of calculation and theoretical investigation for the creation of a powerful (~600 MW) pulsed MHD generator on the combustion products from solid (powder) plasma-forming fuel “Start-2” of a new generation are presented. The scheme, methods, results of calculations, and optimization of characteristics of the pulsed MHD generator with the self-excited resistive “iron-free” magnetic system are described. The local, integral, and specific energy and mass-dimensional characteristics are determined.

Представлены результаты расчётно-теоретического исследования по созданию мощного (≈600 МВт) импульсного МГД-генератора на продуктах сгорания твёрдого (порохового) плазмообразующего топлива “Старт-2” нового поколения. Приведены схема, методики, результаты расчётов и оптимизации характеристик импульсного МГД-генератора с самовозбуждающейся резистивной “безжелезной” магнитной системой. Определены локальные, интегральные, удельные энергетические и массогабаритные характеристики. Полученные характеристики в 1,5-2 раза превышают аналогичные показатели МГДГ первого поколения.

A method for designing a pulsed magnetohydrodynamic generator (MHDG) fueled by the combustion products of the modern aluminized plasma-forming Start-2 solid propellant was developed based on experimental and numerical studies of the characteristics and operating modes of the first-generation 500-MW Sakhalin pulsed MHDG fueled by a solid powder propellant (SPP). This paper presents the results of calculation and optimization of the characteristics of the designed pulsed MHDG with a self-excited resistive “iron-free” magnetic system with an electric power of more than 500 MW. The local, integral, and specific energy, weight, and size characteristics of this generator were determined. Stability parameters of supersonic flow during strong magnetohydrodynamic deceleration of the plasma of combustion products and the time of self-excitation of the magnet were determined. The characteristics of the pulsed MHDG were compared with those of MHDGs fueled by the combustion products of the first-generation SPP. It is shown that the obtained energy, mass, and size characteristics of the MHDG fueled by the Start-2 SPP are much superior to those of the pulsed MHDG fueled by the first-generation SPP.

This paper presents the results of a numerical study of the operating characteristics and operating modes of an electric power system developed as a multipurpose source of high-current pulses. The system consists of a 50 MW pulsed magneto hydrodynamic (MHD) generator, which utilizes an advanced plasma-generating solid propellant and comprises a liquid-free superconducting magnetic system, and a step-up transformer, whose superconducting windings serve as an inductive energy storage device with a current amplification up to 500 kA in the secondary winding. The parameters of the working fluid and supersonic flow in the MHD channel and the main energy and mass-dimensional characteristics of the pulsed MHD generator weighing about 5 tons were determined. The electromagnetic and mass-dimensional characteristics of the superconducting energy storage transformer were calculated in a model formulation. The results of numerical analysis of the operation of the system in the single and cyclic modes with a resistive external load of 0.01 Ohm are presented. It is shown that with complete switching of the current to the load in 1 ms, a load current of 480 kA and an energy of about 12 MJ are generated. The dimensions and weight of the system (about 15 tons) allow it to be used in mobile electric power plants.

The operation of an electromagnetic multirail launcher of solids powered from a pulsed magnetohydrodynamic (MHD) generator is studied. The plasma flow in the channel of the pulsed MHD generator and the possibility of launching solids in a rapid-fire mode of launcher operation are considered. It is shown that this mode of launcher operation can be implemented by matching the plasma flow dynamics in the channel of the pulsed MHD generator and the launching conditions. It is also shown that powerful pulsed MHD generators can be used as a source of electrical energy for rapid-fire electromagnetic rail launchers operating in a burst mode.

The results of the experimental and theoretical investigations aimed at determining the characteristics and features of precision slot cutting with a large number of calibers in sheets of low-carbon steel using the radiation of a single-mode fiber laser with pulse power up to 1 kW are presented. The description of the experimental installation, performance conditions of investigations, and variable parameters are described. Precision cutting of low-carbon steel up to 10 mm with the number of calibers ranging from 30 to 70 at a slot width of ≈60 μm is performed for the first time. Such cutting occurs only in the pulsed-periodic mode using single-mode radiation with a pulse duration of 2–3 ms, a pulse ratio of 2–4, and oxygen, whose influence differs in principle both in various cut regions over the sheet thickness and from cutting with a CO2 laser. The cutting velocity (100–50 mm/min) of sheet steel up to thicknesses of 10 mm with deep channeling, roughness parameters, hardness of the cut surface, which insignificantly (by ≈20%) exceeds the hardness of untreated steel, the phase structure of steel, and the scales of their varying inside metal are measured. The efficiency (≈3%) of precision cutting and the efficiency of transportation of radiation (25%) in large-caliber slot orifices in the “waveguide” mode are determined by the experimental data. The useful specific energy contribution of the laser radiation is w l = N l/(hbv) ≈ 2 × 1012 J/m2 for all studied thicknesses of sheet samples accurate to 20%. A qualitative model of the laser-oxygen precision cutting with deep channeling, which explains the cyclic and interrupting character of cutting and necessity of using oxygen as the cutting gas, is proposed.

We present results of the experimental and theoretical investigation of the characteristics and features of precision large-caliber slot cutting of low-carbon steel sheets with thicknesses up to 10 mm by radiation of 1-kW single-mode fiber laser. Using periodic-pulsed single-mode laser radiation and oxygen as the cutting gas, slots with calibers from 20 to 60 (in some cases – up to 100) and widths up to about 60 microns have been obtained. The cutting speed (50—100 mm/min) was measured and the efficiency of precision cutting (»3%) and efficiency of laser radiation transport in the waveguide mode (»25%) were estimated. The morphology and roughness parameters of the cut surface were determined. Variation of the hardness and phase structure of steel in the direction of normal to the slot wall were studied. A qualitative model of laser oxygen precision slot cutting with deep channeling is proposed.

Deep electromagnetic (EM) study of the earth’s crust requires the use of a powerful controlled source of the EM field. In this paper, we present a concept of the application of multimegawatt EM pulses generated, for example, by self-contained MHD facilities of short-term operation (3-12 s), for geophysical and geological surveys. We describe the physical and engineering background of pulsed MHD facilities fueled by a solid propellant of 10-100 MW of electric power, developed in Russia. The paper also summarizes the results of experimental and methodological studies performed during the last 30 years in different regions of Russia, Kirghizia and Tajikistan. The results of this development provided the foundation of a new technology for deep geoelectrical exploration of hydrocarbon reservoirs on land and offshore.

Results are given of experimental and numerical investigations of plasma of products of combustion of pyrotechnic fuel [(64–69%)Mg+(35–30%)KNO 3 +1% process additions] in air for the oxidizer excess coefficient α in the range from 0.8 to 1.1 and for different conditions in the combustor and MHD channel. The choice of the optimal formula of pyrotechnic fuel for use in experiments is analyzed and validated. The structural scheme and description are given of the Pamir-0-KT experimental facility. The operating time of the MHD facility was 3.6 s, with the flow rate of combustion products of about 2 kg/s at a pressure in the plasma generator of p ch ≈ 4 MPa. The maximal value of the MHD-channel cross-section average plasma conductivity of 23 S/m at an electron mobility of 0.45 T −1 is obtained for the composition of pyrotechnic fuel of 64%Mg+35%KNO3 at α = 0.96, pressure of 0.08 MPa, temperature of 2700 K, and flow velocity of 1900 m/s. It is demonstrated numerically that the value of conductivity σ 0 in the flow core is at least 50 S/m. The dependences of electrode voltage drops on current density are determined. The possibility is demonstrated of non-contracted flow of current to the surface of “cold” (800 K) electrode at average current densities up to 3×10 4 A/m 2 and α ≈ 0.9.

Results are given of experimental and numerical investigations of electrical conductivity and mobility of electrons in the products of combustion of hydrogen-oxygen fuel seeded with cesium or potassium-sodium eutectic. The experiments were performed in model (flow rate of 0.9 kg/s, thermal power N th ≈7 MW) and large-scale experimental (flow rate ≈12 kg/s, N th ≈ 150 MW) facilities with the pressure in the combustor ranging from 2 to 6 MPa, oxidizer excess coefficients of 0.6 to 1.1, mass fractions of the seed in the fuel of 0.3 to 0.9 with the Mach number M ≈ 2.4. The basic characteristics, structural schemes, and general views of the facilities are given. When cesium is used for seeding, the experimentally obtained values of electrical conductivity may be as high as σel ≈ 20 S/m, those of σelν2 ≈ 115 S/m (km/s)2, and of electron mobility − 0.11 T−1 at a pressure of ≈0.3 MPa, temperature of ≈2800 K, and flow velocity ν ≈ 2500 m/s. Under the same conditions for combustion products seeded with KNa eutectic, we have σel ≈ 9 S/m, σelν2 ≈ 65 (S/m)(km/s)2, and electron mobility of 0.09 T−1.

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