[en] In this study, the spatial distribution of plasma parameters in an experimental RF plasma device was performed. An automatic scanning system for the spectrometer and linear drive to detect plasma radiation was developed and implemented. The system is used to measure the spatial distribution of the electron temperature in a plasma discharge. (paper)

[en] The influence of micro- and nanostructured surfaces on the boiling characteristics is introduced. The working surfaces were obtained by processing the samples with a laser, plasma, electron, or ion beam. Some of the samples were preliminarily coated with nanocarbonic materials. The morphology and the contact angle of wetting during interaction with water were studied for surfaces. A description of the apparatus for investigating the Leidenfrost temperature is introduced. (paper)

[en] The PLM-2 linear magnetic plasma device is designed for the steady-state hours- long plasma confinement. It is the upgraded PLM plasma device. Its parameters will provide the relevant fusion reactor plasma loads on materials. The machine is designed both for fundamental studies of plasma-surface interactions under conditions of high heat and particle fluxes, and for the tests of plasma-facing components under realistic plasma conditions in the high-heat-flux facility. The PLM-2 facility is an advanced linear plasma device uniquely capable of producing plasma conditions similar to those expected in the divertors of the fusion reactors such as ITER, fusion neutron source FNS and DEMO under conditions of steady-state operation. In this article, we describe the PLM-2 design parameters. The PLM-2 device has no analogues in Russia; its parameters are similar to those of the most high-power devices in the world, such as the MAGNUM-PSI, and it is going to be built in Moscow at National Research University “MPEI”. (paper)

[en] There has been developed an approach to the production of graphene as a result of the thermal reduction of graphene oxide (GO). GO has been synthesized by the use of the modified Hummers method with utilization of sodium nitrate and concentrated sulfuric acid. A paper-like material of 40 – 60 μm in thickness and 1.2 g/cm³ in density was formed on a filter after deposition from dispersion. The material was cut onto samples of about 15×25 mm² in size which were experienced to the thermal treatment at various temperatures between 100 and 800 °C. This resulted in a set of GO samples reduced to various degrees. The degree of reduction was determined on the basis of measurements of the conductivity. Along with that the evolution of samples density was studied as the annealing temperature was enhanced. The analysis of the X-ray photoelectron spectra of partially reduced GO permitted the determination of the dynamics of changing the chemical composition of the material in the process of the thermal treatment. The analysis of Raman spectra of the GO samples indicates rather high degree of the disordering of the material. A possibility of the usage of the material produced as a nanocarbon coating in experiments on the interaction of high intense liquid flows with a wall surface is discussed. (paper)

[en] We present the results of an experimental study of heat transfer regimes during cooling in water of high-temperature, heated steel balls with a technically smooth and modified surface. The modification consisted of the application of a finely dispersed carbon coating to the surface followed by electron beam treatment. When the samples are placed in subcooled water, an intensive heat transfer regime occurs on the both samples; it appeared upon film boiling with heat fluxes on the surface up to 6 MW/m². The heat flux values based on the initial cooling thermograms were obtained from a one-dimensional inverse heat conduction problem. The carboncoating leads to a decrease in the surface temperature, which corresponds to the transition to the intensive cooling mode, whereas the intensive cooling mode itself is identical for samples with the different surface treatments. Experimental results confirm the approximate model proposed for the conditions for the occurrence of the intensive cooling regime during film boiling of a subcooled liquid.

[en] Nondestructive depth profiling method based on reflected electron spectroscopy is presented. Large loss spectra of wide energy range is analyzed. Spectra analysis is performed using two approaches: boundary problem solution using invariant imbedding method and approximate interpretation based on Straight Line Approximation with correction coefficients, which depend on ration of evaporated layer thickness and transport mean free path. It is shown that the transport mean free path, not the inelastic mean free path, limits the information depth of the method in opposite of X-ray photoelectron spectroscopy, elastic peak electron spectroscopy. This fact significantly increase depths that can be analyzed using presented method. Thickness of the evaporated Nb layer on the Si substrate is determined.

[en] It has been created the automated laboratory complex with remote access. It provides access for students to laboratory resources of the National Research University «MPEI» in the multi-user mode in real time. The automated remote laboratory complex provides the study of the theory and technique of experimental determination physical quantities; the execution of work in simulation mode; the remote execution of work at real equipment, acquisition and analyzing data, the estimation of students work results. At present time the four laboratory setups are available. (paper)

[en] In this work, we measured thermal conductivity of tungsten surface layers grown under helium plasma irradiation in the PLM device at NRU “MPEI”. A stochastic nanostructured fuzz-type surface with fibers of less than 50 nm has grown on the irradiated samples. The duration of discharges in the PLM reached 200 minutes, the thermal load on the surface of the test plates during plasma irradiation was more than 1 MW / m² and more. Scanning electron microscopy (SEM) analysis revealed the nanostructured fuzz layer of the depth of approximately 1.6 µm on the tungsten exposed to plasma at 950 °C. The density of fuzz layer was observed to depend on the plasma load. We adopted the well-established laser flashing method in order to measure the heat transfer characteristics of tungsten nanostructured surface. Results from measurements show that heat exchange was reduced in the fuzz layers compared to that of pristine tungsten. This reduction can be attributed to the fuzz fibers on the surface. (paper)

[en] Modification of a steel surface by coating with fullerenes C₆₀ and subsequent treatment by intense laser radiation has been investigated. The initial samples are made of low-carbon steel. The laser source is a commercial LTA4-1 laser with a wavelength of 1.064 µm, pulse energy up to 12 J, and pulse width of 2 ms. The obtained dependences of the surface microhardness on the specific laser energy are nonmonotonic with a maximum in the range of 100–150 J/cm². An eight-fold increase in the surface microhardness can be reached under optimal treatment conditions. There is an increasing dependence of the degree of surface strengthening on the fullerene-coating thickness. In addition, the laser irradiation of the treated surface is accompanied by a decrease in the friction coefficient by several tens of percent. The experimental results are compared with the data of similar measurements for nanocarbon soot used as the coating, which was obtained by the electric-arc sputtering of graphite with subsequent extraction of fullerenes.

[en] The titanium plates were irradiated with plasma in stationary helium discharges in the PLM plasma device. The duration of discharges in the PLM installation reached 200 minutes. The thermal load on the surface of the test plates is more than 1 MW / m². The heating temperature of the plates reached 700-900 °C. Scanning electron microscopy of the samples revealed a highly porous stochastic nanostructured surface with dimensions of structural elements less than 500 nm. Such novel material is of interest for nuclear, chemical, hypersonic technologies, as well for biotechnologies and biomedical applications. (paper)