bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hole size effect on microhollow cathode discharge in air
Authors: Moshkunov S I , Nebogatkin S V , Romanov K I , Shershunova E A 
Published: November 2021

Abstract
In this work the values of main electrical parameters of the microhollow cathode discharge in atmospheric air (peak discharge current, discharge ignition voltage) depending on the diameter of the hole in the cathode were obtained. It was experimentally found that at currents up to 2 mA, the discharge operated in a self-pulsing mode. According to the experimental results it was concluded that the value of the discharge ignition voltage at average discharge current exceeding 2 mA didn’t depend on the hole diameter.
Runaway of electrons and initiation of explosive electron emission during pulse breakdown of high-pressure gases
Authors: Mesyats G A , Zubarev N M 
Published: November 2021

AbstractWe propose a scenario of the initiation of explosive electron emission on the boundary of the electrode and a high-pressure gas. According to this scenario, positive ions are formed due to the gas ionization by field-emission electrons and accumulated in the vicinity of protrusions of micron size at the cathode. The distance between the ion cloud and the emitting surface decreases with increasing pressure which results in a growth of the local field. As a consequence, an explosive growth of the emission current density occurs for a dense gas (the gas with the pressure of tens of atm). As a result, explosive-emission centers can be formed in dozens of ps. These centers give a start to plasma channels expanding towards the anode. Runaway electron flow generated near the channel heads ionizes the gas gap, causing its subnanosecond breakdown.
Experimental installation for studying cathode plasma processes in vacuum gap of pulsed electron accelerator with gas or liquid injection
Authors: Egorov I S , Klimkin A V , Poloskov A V , Serebrennikov M A , Trigub M V 
Published: November 2021

Abstract
One of the directions of using plasma sources is the formation of plasma emitters for electron beams as part of direct-action charged particle accelerators. The parameters of the accelerator generators require mutual matching with the characteristics of the plasma emitters. The paper describes the design, composition and diagnostic equipment of an experimental stand based on a vacuum chamber of a pulsed electron accelerator for testing plasma sources of pulsed electron beams. The stand includes a vacuum volume with a high-voltage bushing, pumping out pipes, diagnostic windows along the perimeter and a mounting flange of a complex device for diagnosing the characteristics of pulsed electron beams. The stand provides the possibility of controlled supply of gas and liquid to the formation region of the plasma emitter of electrons under the influence of an accelerating voltage pulse. The location of the diagnostic windows and flanges of the stand allows direct optical observations of the plasma formation region in the frontal and profile directions. The use of the stand will make it possible to determine the characteristics of the tested plasma emitters for their operation as part of a vacuum diode of pulsed electron accelerator.
Magnetic field influence on the Penning discharge characteristics
Authors: Mamedov N V , Rohmanenkov A S , Solodovnikov A A 
Published: November 2021

Abstract
In this work characteristics of pulsed penning ion source for miniature linear accelerators was investigated by experimental measurements and PIC (Particle-In-Cell) simulations. The paper presents dependences of the discharge current and extracted current on intensities of the uniform magnetic field for different pressure. Also, typical examples of the current pulse waveforms obtained by PIC simulation and experiment for different magnetic field are presented. The simulated electron and ion distributions inside discharge gap give qualitative explanation of the experimentally observed fluctuations in current pulses. These current fluctuations arise as a result of the violation of the electric field axial symmetry due to the electron spoke movement of the towards the anode.
Generation of plasma in low-pressure discharge
Authors: Nikulin S P 
Published: November 2021

Abstract
A hydrodynamic model of plasma has been developed, which takes into account both secondary and primary electrons. It has been shown that a solution with a plasma potential higher than the anode potential is possible if the ionization frequency is higher than some critical value. At lower ionization frequencies, it is possible to obtain a solution with a plasma potential below the anode potential
Multi-cycle of AISI 5135 steel modification by irradiation of the “film (Si (0.2 μm) + Nb (0.2 μm))/(AISI 5135 steel) substrate” system with an intense pulsed electron beam
Authors: Koval N N , Ivanov Yu F , Shugurov V V , Teresov A D , Petrikova E A 
Published: November 2021

Abstract
Steel AISI 5135 surface layer modification carried out by high-cycle high-speed melting of the “film (Si + Nb)/(steel AISI 5135) substrate” system with an intense pulsed electron beam with an impact area of several square centimeters, have been implemented in a single vacuum cycle on the “COMPLEX” setup. The regime of the system “film (Si (0.2 μm) + Nb (0.2 μm))/(steel AISI 5135) substrate” irradiation with an intense pulsed electron beam (20 J/cm2, 200 μs, 3 pulses, 3 cycles) which makes it possible to form a surface layer with high thermal stability have been revealed. This layer is characterized by high hardness, more than 3 times higher than the hardness of AISI 5135 steel in the original (ferrite-pearlite structure) and wear resistance, more than 90 times higher than the wear resistance of the initial AISI 5135 steel. It is shown that the high strength and tribological properties of steel are due to the formation of the hardening phase particles (niobium silicide of Nb5Si3 composition).
Charge and elemental composition of plasma generated by sputtering of powder target from amorphous boron
Authors: Ivanov Y F , Shugurov V V , Krysina O V , Prokopiev V E 
Published: November 2021

Abstract
One of the effective and widespread methods of surface hardening of metal products is an ion-plasma saturation of the surface of machine parts and mechanisms with various elements (nitrogen, oxygen, carbon). Less investigated method is the process of ion-plasma saturation of the metals and alloys surface with boron. The purpose of the present work is to develop a method for the formation and study of parameters (electron temperature, plasma potential and concentration), elemental and charge composition of plasma generated at sputtering of a target from amorphous boron powder. To achieve the stated goal, a discharge system with a hot anode made of powder boron, as well as a pulse arc evaporator with a hot cathode made of sintered boron powder, was developed, designed, created and tested. Charge and elemental composition of boron-containing plasma generated during powder target sputtering from amorphous boron are defined by optical spectrometry method. It is shown that the generated plasma contains mainly neutral atoms and single-charge boron ions, as well as iron, silicon, copper and argon particles.
Development of the computer model of the plasma installation
Authors: Okulov R A , Popov E V , Gelchinsky B R , Rempel A A 
Published: November 2021

Abstract
Mathematical model of a plasma installation for the production of metal powder and coating has been developed. The problem of creating an objective mathematical model of the plasma jet flow is solved, which adequately describes the real process and allows predicting the parameters of the plasma jet. The value of the temperature of the plasma jet at a characteristic point located on its axis is investigated. The computer model was verified by carrying out a full-scale experiment. Comparative analysis of the results of numerical and field experiments showed satisfactory convergence. It is shown that the temperature of the plasma jet flow obeys the normal Gaussian distribution. The research results can be used to improve processes and technological equipment.
Investigation of the plasma composition of a discharge with a self-heating hollow cathode and an active anode in a gas mixture with titanium and hexamethyldisilazane vapors
Authors: Menshakov A I , Bruhanova Yu A , Surkov Yu S , Skorynina P A 
Published: November 2021

Abstract
The analysis of composition of low-pressure (~0.1-1 mTorr) hollow cathode arc plasma in Ar+N2 gas mixture with Ti+hexamethyldisilazane vapors was carried out by optical emission spectroscopy. The influence of HMDS flow rate (1-10 g/h), discharge current (10-50 A) and Ti-vapors flow on hexamethyldisilazane decomposition degree and plasma composition and was investigated. The proposed plasma activation method provides both an intense flow and a high activation degree of metal vapors, and a sufficient decomposition degree of precursor vapors for the formation of solid TiSiCN coatings at a high deposition rate. Test coatings with a thickness of 6 microns and a hardness of 31 GPa were obtained in 1 hour at 400ºC.
Effect of the O2 dissociation degree on the rate of anodic evaporation of Al in a low-pressure arc
Authors: Kamenetskikh A S , Gavrilov N V , Krivoshapko S V , Tretnikov P V , Chukin A V 
Published: November 2021

Abstract
The results of probe diagnostics and optical emission spectroscopy of Ar-O2 plasma of a low-pressure arc generated under anodic evaporation of Al and an increased (0.32 – 0.48) degree of O2 dissociation are presented. It is shown that an increase in the degree of O2 dissociation at a constant gas flow into the discharge gap leads to a significant (more than 1.5 times) decrease in the density of the evaporated atoms flux and a corresponding decrease in the coating deposition rate. The observed effect is due to the accelerated growth of the oxide film on the melt surface, which leads to the limitation of the flow of evaporated Al atoms by the rate of diffusion through the alumina.
Influence of electron-beam heating modes on the structure of composite ZrO2-Al2O3 ceramics
Authors: Klimov A S , Bakeev I Y , Zenin A A 
Published: November 2021

Abstract
The article presents the results of electron beam sintering of composite ceramics based on Al2O3 and ZrO2 powders. Samples were made with different contents of Al2O3 and ZrO2 components and different pressing pressures. Sintering was carried out in vacuum at a helium pressure of 30 Pa. An electron beam generated by a forevacuum plasma electron source was used for sintering. It is shown that the sintering result depends on the pressing pressure and the percentage of components. The influence of the geometry of the samples and their composition on the temperature drop over their volume during sintering has been determined.
Electron beam sintering of Mn-Zn ferrites using a forevacuum plasma electron source
Authors: Klimov A S , Bakeev I Y , Zenin A A 
Published: November 2021

Abstract
The article presents the results of electron beam sintering without applying pressure of Mn-Zn ferrites in an oxygen environment. Samples for sintering were made from fine powders and pressed at various pressures into compacts in the form of disks. Measurements of the elemental composition and structure of the sample after sintering are presented. It is shown that the result of sintering depends on the pressing pressure of compacts, time and temperature of sintering.
Influence of temperature on tungsten carbide formation in a beam plasma discharge
Authors: Zhanbolatova G K , Baklanov V V , Skakov M K , Sokolov I A , Bukina O S , Kozhahmetov Ye A , Orazgaliev N A 
Published: November 2021

Abstract

This paper presents a method of tungsten surface carbidization using a plasma-beam setup to assess the effect of temperature on the formation of tungsten carbides. Methane was used as a plasma-forming gas. The working gas pressure in the chamber was (1.3–1.4)10−1 Pa. Experiments on the formation of carbides were carried out at different temperatures (700-1000°C). It was recorded that at a temperature of 700°C, crystallization centers of a carbon film appear on the sample surface. With an increase in the irradiation temperature to 800°C and 900°C, the surface of the samples is covered with a continuous carbon film. As a result of the experimental work carried out, it was found that the formation of tungsten semicarbide occurs at 900°C. A further increase in temperature leads to the formation of tungsten monocarbide.
Comparative study on high-voltage nanosecond pulses and dielectric barrier discharge effects on surface morphology and physico-chemical properties of natural pyrrhotite
Authors: Bunin I Zh , Khabarova I A 
Published: November 2021

Abstract
In this paper we used analytical electron microscopy, potentiometric titration (electrode potential), sorption and flotation measurements and other methods to study changes in the surface morphology, electrochemical, and physicochemical properties of the natural pyrrhotite exposed to nonthermal action of the repetitive nanosecond high-power electromagnetic pulses and low-temperature plasma of dielectric barrier discharge in air at atmospheric pressure. As a result of exposure to high-voltage nanosecond pulses, a sharp shift in the electrode potential of pyrrhotite to the region of negative values caused a decrease in the sorption of the anionic collector on the mineral, a decrease in the hydrophobicity of the surface and flotation of the mineral was due to an increase in the content of oxidized ferric iron on the mineral surface. Dielectric barrier discharge treatment caused the shift of the electrode potential to the region of negative values (–60 mV) in the range of pH 9.7-12, which causes the effect of a decrease in the sorption and flotation activity of pyrrhotite. The advantages of using the short-term (10-30 seconds) energy impacts for structural and chemical modification of the surface and physicochemical properties of sulfide minerals of iron are shown.
Effect of ion irradiation on structural state and mechanical properties of naturally-aged hot-pressed D16 (Al-Cu-Mg) alloy profiles
Authors: Gushchina N V , Ovchinnikov V V , Kaigorodova L I , Rasposienko D Y , Vichuzhanin D I 
Published: November 2021

Abstract
The effect of irradiation with 20 keV argon ions on the mechanical properties, structure, and phase composition of quenched and then naturally aged, hot-pressed profiles (6 mm thick) from the D16 alloy of the Al-Cu-Mg system has been studied. It was found that short-term irradiation with Ar+ ions (E = 20 keV, j = 200 μA/cm2, F = 1×1016 cm-2, irradiation time 8 s) leads to transformation of the microstructure and phase composition of the alloy. The coarsening of the initial subgrain structure occurs near the sample surface. Both in the surface layer and at a distance of ∼ 150 μm from it, partial dissolution and fragmentation of complex intermetallic compounds of crystallization origin located along grain boundaries are observed, as well as a decrease in the size and change in the morphology of Al6(Fe, Mn) intermetallic compounds of crystallization origin are observed too: the distribution density of lamellar precipitations decreases, and equiaxial precipitations disappear. Under the influence of irradiation, the decomposition of the supersaturated solid solution is activated with the formation of a more stable phase S’. As a result of ion-beam treatment in this mode, the plasticity of the alloy increases while maintaining the strength properties.
Ion current optimization in a magnetron with tunable magnetic field configuration
Authors: Kaziev A V , Ageychenkov D G , Tumarkin A V , Kolodko D V , Sergeev N S , Kharkov M M , Leonova K A 
Published: November 2021

Abstract
The response of the ion current in the substrate region to the magnetic system configuration of a circular magnetron was studied during direct current sputtering of aluminum target. The unbalancing degree induced by changing of magnets’ positions was modelled with finite element methods. The ion saturation current in the substrate region showed more than twofold variation with unbalancing degree in the range 0.6–1.2. The dependence was non-monotonic, and the system was optimized to maximize the substrate ion current. The Langmuir probe diagnostics showed plasma density ~ 1016 m−3 in the optimized magnetic configuration.
Modification of stainless steel based on synergistic of low-energy high-intensity ion implantation and high-current electron beam impact on the surface layer
Authors: Ryabchikov A I , Korneva O S , Sivin D O , Ivanova A I , Lopatin I V , Bozhko I A 
Published: November 2021

Abstract
The results of experiments on low-energy implantation of AISI 321 stainless steel by nitrogen ions are presented. The treatment was carried out by a pulsed beam of nitrogen ions obtained using a ballistic ion focusing system. The surface modification occurs with the formation of a two-layer structure, which is typical for ion-plasma nitriding processes of stainless steels. The thickness of the modified layer can reach 27 μm after 1 hour of ion-plasma treatment. The influence of subsequent modification of the ion-doped layer by the action on the surface of the pulsed high-current electron beam of microsecond duration is studied. The work presents the results of the studying the regularities of changes in the depth distribution of dopants, microstructure and phase composition of the modified and matrix layers by optical metallography, diffraction analysis and transmission electron microscopy.
Energy density distribution of a modulated electron beam in a source with a plasma cathode based on a low pressure arc
Authors: Shin V I , Moskvin P V , Vorobyov M S , Devyatkov V N , Koval N N 
Published: November 2021

Abstract

The article presents the results of studies devoted to the study of the energy density distribution in the amplitude-modulated regime of electron beam generation. It is shown that in the first ≈ 50 μs of the duration of the beam current pulse, its spatial rearrangement occurs, due to the development of the arc discharge current. Thus, the rearrangement of the arc current, which develops from the axis of the system, leads to an axial diving of the emission current density and the beam current density on the target. With the development of the arc current, the energy density on the target on the axis of the system decreases and after ≈ 50 μs takes on a steady-state value, which can change only as a result of a change in the conditions for generating an electron beam or the transition to a modulated regime of electron beam generation. It has been experimentally shown using calorimetric measurements that the shape of the electron beam current pulse with its amplitude modulation with a pulse duration of more than 100 μs has little effect on the distribution of the beam energy density in the target region.
Formation of a silicon-niobium-based surface alloy using electron-ion-plasma surface engineering
Authors: Shugurov V V , Koval N N , Ivanov Yu F , Teresov A D , Petrikova E A 
Published: November 2021

Abstract
The results of the development and study of the modes of formation of a surface alloy based on silicon and niobium on steel 40X using electron-ion-plasma engineering of the surface are presented. The surface alloy was created in several stages: first, layers of silicon and niobium were deposited successively, and then electron-beam remelting of the surface took place. After that, the samples were subjected to nitriding. The dependences of the change in the surface hardness of the samples on the processing modes are shown. In the optimal processing mode, the surface hardness increased by almost 70 times compared to the original material.
Interaction of plasma with beryllium
Authors: Sokolov’ I A , Skakov M K , Miniyazov A Z , Tulenbergenov T R , Zhanbolatova G K 
Published: November 2021

Abstract
In this work shows some results of studying the microstructure of HP-56 beryllium after plasma irradiation. The experiments revealed a change in the microstructure of beryllium after irradiation with hydrogen, deuterium and helium atoms. The pore diameter and their bulk density increase depending on the plasma parameters.
Effect of the annealing temperature on the structural properties of hafnium nanofilms by magnetron sputtering
Authors: Win Thant Sin , Kuzmenko A P , Rodionov V V , Than Min Myo 
Published: November 2021

AbstractIn this work investigated the effect of the annealing temperature on hafnium nanofilms obtained by DC magnetron sputtering on Si substrates. The nanofilms annealed through 100°C to 700°C by a High-Temperature Strip Heater Chambers (HTK-16N) on an X-ray Diffractometer (XRD). The microstructure and morphology of the films at different temperatures were investigated by XRD, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Raman Microspectrometer (RS). It was found that annealing affects changes in the lattice strains, texture, grain size, and roughness of Hf nanofilms. According to XRD data, the structure of the thin films showed amorphous from room temperature to 100°C and starting from a temperature of 200°C were changed crystallization. At 500°C a monoclinic structure corresponding to hafnium dioxide HfO2was formed in hafnium nanofilms.
Electron-beam deposition of thermoconducting ceramic coatings for microelectronic devices
Authors: Oks’ E M , Tyunkov A V , Yushkov Y G , Zolotukhin D B 
Published: November 2021

Abstract
This paper presents the experimental study of dielectric coatings based on aluminum oxide (Al2O3) and aluminum nitride (AlN) ceramics as applied to their use in microelectronics. It is shown that the coatings obtained by electron-beam evaporation of ceramic in forevacuum pressures (1-100 Pa) endow devices with required dielectric parameters and improves heat sink from the surface of monolithic integral circuits.
Plasma nitriding in complex post-processing of stainless steel parts obtained by additive laser technology
Authors: Makarov A V , Kuznetsov V P , Skorynina P A , Sirosh V A , Vladimirov A B , Lezhnin N V , Kolmakov S V 
Published: November 2021

Abstract
Considered are the prospects of applying complex post-processing for an additive manufactured product with the deposition of a multilayer composite coating [Ti0.2C0.8/a-C]40 at the final stage. It is shown that heat treatment, finish milling, ion-plasma nitriding and burnishing with a sliding diamond indenter of a PH1 steel part obtained by selective laser melting (SLM) before deposition of a thin-film coating provides the coating with a minimum surface roughness Ra = 82-86 nm and a maximum hardness of 25.2 ± 1.4 GPa with an increase in the microhardness of the entire “coating-substrate” system.
Structure and mechanical properties of stainless-steel specimens, made by additive method, after pulsed electron beam treatment
Authors: Teresov A D , Petrikova E A , Krysina O V , Prokopenko N A , Ivanov Yu F , Akhmadeev Yu H , Semenov G V 
Published: November 2021

Abstract
The article presents a method for finishing the surface of metal products made by sequential electron-beam surfacing, which consists in modifying the surface with an intense low-energy electron beam of submillisecond duration. On the example of 308LSi stainless steel, the results of such processing are demonstrated, the optimal modes of exposure are determined. It is shown that as a result of pulsed electron-beam processing, a homogeneous polycrystalline structure without cracks is formed on the surface with unchanged, relative to the initial material, elemental composition, strength (microhardness) and tribological (wear rate) properties. In this case, the surface roughness is reduced to 2.1 times in the longitudinal direction relative to the surfacing plane, to 5.2 times in the transverse direction. Tensile tests of specimens showed anisotropy of mechanical properties depending on the direction of tension relative to the surfacing plane, which decreases after surface pulse electron-beam processing.