bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of the expansion velocity of the plasma high-current vacuum arc discharge
Authors: Zhigalin A S , Rousskikh A G , Oreshkin V I , Artyomov A P 
Published: November 2021

Abstract
In this work, we present experimental results on measuring the velocity of vacuum arc discharge plasma expansion. In the experiments, two designs of plasma guns were used. In the first version, the end of the arc discharge cathode was located below the plane of the anode, and the surface of the insulator separating them was parallel to the axis of symmetry of the plasma gun. In this design, the arc discharge plasma escapes the anode through a hole, the diameter of which coincides with the diameter of the cathode. In the second variant, the plane of the end face of the arc discharge cathode coincided with the plane of the anode, and the surface of the insulator separating them was located perpendicular to the axis of symmetry of the plasma gun. To obtain an image of plasma in the optical range, an FER-7 optical streak camera was used. Based on the results obtained, it can be concluded that the expansion velocity of the plasma of a high-current vacuum arc discharge does not depend on the design of the guns considered in this experiment.
Method of nanosecond triggering for a sealed-off pseudospark switch
Authors: Argunov G A , Landl N V , Korolev Y D , Frants O B , Geyman V G , Nekhoroshev V O 
Published: November 2021

Abstract
This paper describes a method of nanosecond triggering for the modified version of the commercially produced pseudospark switch TPI1-10k/50. The switch uses the trigger unit with the auxiliary glow discharge, and the proposed method is based on the principle of the current interception from the trigger unit to the grounded cathode cavity when the trigger pulse arrives. Different electric circuits for triggering have been investigated. In the circuit, where the so-called trigger resistor or the trigger inductance are available, in the whole range of hydrogen operating pressure, the range of the delay time of triggering corresponds to (80–100) ns with a jitter of (3–6) ns. In the electric circuit, where the trigger resistor is shortened, the delay time increases to about (110–140) ns. However, the jitter remains at approximately the same level.
Investigation of the near-surface matter density radial distribution in the skin explosion of cylindrical conductors
Authors: Datsko I M , Labetskaya N A , Vankevich V A 
Published: November 2021

Abstract
Investigations of the near-surface plasma formation process during skin explosion of cylindrical duralumin and copper conductors in rapidly increasing magnetic fields with their induction up to 500 T were carried out. The formation of plasma on the conductor surface was recorded by its glow in the visible range using a four-frame optical camera with an exposure time of each frame of 3 ns. The internal structure of the surface plasma, the assessment of the density of matter in it and its radial distribution were investigated using radiography pictures obtained by X-ray transmission with hv > 0.8 keV, which is formed at the “hot point” of the X-pinch. The dependences of the load substance density on its radius were determined and constructed from the obtained X-ray diffraction patterns at different points in time from the beginning of the current. So at 216 ns at a radius of 1.8 mm of a duralumin conductor with an initial radius of 1.485 mm, the density of the substance is estimated to be 0.0068 g/cm3.
Plasma channel dynamics in sub- and microsecond discharges in water
Authors: Zherlitsyn A A , Kozyrev A V , Semeniuk N S , Kondratiev S S , Alexeenko V M 
Published: November 2021

Abstract
Simulation results of a fast electric discharge and a strong acoustic wave in the water is performed. A theoretical model of a high-current plasma channel is presented. The model accounts for the energy ratio between the input electric power and the plasma channel conductivity, and adiabatic expansion mechanism of this channel in water. It allows you to calculate the dynamics of the expansion of the channel and the generation of a radially diverging acoustic wave. The presented study makes it possible to estimate the probable parameters of the phenomenon: when electric energy is introduced into the channel, its expansion velocity reaches 1.9 km/s, electrons number density in the plasma is up to 2·1020 cm−3. In this case, a strong acoustic wave propagates with a sonic speed (~ 1500 m/s), and the pressure amplitude in the vicinity of the plasma channel can reach 200 MPa. The stability of the model in relation to variations in the initial task parameters has been analyzed. The calculated data for the acoustic wave are in good agreement with the measurements.
The dynamics of the formation of initial stages of a transverse nanosecond discharge with an extended slot cathode in argon
Authors: Ashurbekov N A , Iminov K O , Zakaryaeva M Z , Shakhsinov G S , Rabadanov K M 
Published: November 2021

Abstract
The dynamics of the main characteristics of a limited nanosecond discharge in an extended slot cathode in argon at the values of the applied voltage to the electrodes close to the values of the voltages of the formation of a volume discharge are studied by numerical simulation. It is shown that this type of discharge can be used to create an extended dense plasma column with a high density of charged and excited particles. The analysis of the spatiotemporal dynamics of development of the electron density and the electron energy distribution function was carried out. It is shown that the high-energy electrons are formed at the front of the ionization wave due to the hollow-cathode effect.
Investigation of the aluminum electrodes erosion of a plasma gun during the operation of a high-current vacuum arc discharge
Authors: Artyomov A P , Rousskikh A G , Zhigalin A S , Rousskikh I A , Tyukavkin A G , Oreshkin V I 
Published: November 2021

Abstract
The aim of this work was to obtain magnitude quantitative estimates of the “closed-type” plasma gun aluminum electrodes erosion that occurs during the course of a high-current vacuum arc discharge. The experimental setup consisted of two current generators. The first generator capable of generating a current with an amplitude of up to 450 kA and a rise time of 500 ns was used as a current source for a plasma gun. The second one was used as an X-ray radiograph to visualize the object under study in the soft X-ray range (hv ≈ 0.5–3 keV). Quantitative distributions of the plasma linear mass are obtained both along the radius and along the length of the jet at different times. It was shown that the erosion properties of the electrode material are related to the current characteristics of the arc discharge current.
Determination of the voltage drop on a high-current vacuum arc discharge under conditions of a limited cross-section of the plasma flow
Authors: Rousskikh A G , Zhigalin A S , Oreshkin V I , Artyomov P 
Published: November 2021

Abstract
The work is devoted to the study of the high-current vacuum arc discharge characteristics under conditions of a limited cross-section of the plasma flow. The experiments were carried out on the IMRI-5 setup with a sinusoidal arc current amplitude of 300–350 kA and a rise time of 500 ns. Aluminum rods with diameters from 3 to 7 mm were used as a cathode. The plasma flow was formed in a channel whose diameter was equal to that of the cathode. The features of the formation of a plasma jet with various configurations of the used plasma gun are described. The electrophysical parameters of the arc discharge are presented. Theoretical estimates of the voltage drop across the high-current arc during the outflow of a plasma flow through holes with a limited diameter are provided.
Features of the electron avalanche formation process in a strongly inhomogeneous electric field under high overvoltages
Authors: Mamontov Yu I , Lisenkov V V 
Published: November 2021

Abstract
The simulation of the electron avalanche formation process in subnanosecond discharges of high pressure was carried out by means of the Monte-Carlo approach. The discharge gap under consideration was of the configuration “the finger-shaped cathode – the hemispherical anode”. The presence of a conic-shaped microprotrusion on a cathode surface was assumed. Such the electrode configuration provided the strongly inhomogeneous distribution of an electric field. A gas simulated was nitrogen at a pressure of 6 atm. An average electric field strength across the discharge gap was varied from 200 kV/cm up to 400 kV/cm. Microprotrusion height was varied from 0 um up to 30 um. The critical size and formation time of an electron avalanche were determined under various conditions simulated. The threshold electric field strength for electrons to transit into the continuous accelerating regime was calculated for various heights of the microprotrusion. The applicability of the non-self-consistent Monte-Carlo technique for the investigation of the runaway electron kinetics and the correct simulation of the runaway electron beam transport across the discharge gap was shown.
Some issues of the operation of plasma opening switches
Authors: Loginov S V 
Published: November 2021

Abstract
The paper analyzes some processes in a plasma opening switch with a conduction time of ~ 100 ns. Relations are derived for assessing the evolution of the ion current to its space charge-limited state and for estimating its maximum possible density. It is shown that the ion current density reaches its extremum before electron magnetization. Estimates for the electromagnetic energy delivered to the switch are also presented demonstrating that this energy is spent equally for creating a magnetic field in the plasma volume and for its ohmic heating.
Arc discharges operation in “elion” mode
Authors: Lopatin I V , Akhmadeev Yu H , Kovalsky S S , Ignatov D Yu 
Published: November 2021

Abstract
This paper presents the results of a study of an electron-ion-plasma alitization system using two arc plasma generators: a gas plasma generator based on a non-self-sustained arc discharge with a thermionic cathode “PINK” and a gas-metal plasma generator based on an arc discharge with a cathode spot. The system for discharges supplying and biasing of the samples assumes two sub-modes of operation: the ion cleaning sub-mode (ion sub-mode) and the sub-mode of samples electron heating (electron sub-mode), thus realizing the “elion” mode of the system operation. During the experiments, both the dependences of the average values of currents and voltages of discharges burning and probe measurements of the instantaneous plasma parameters values in both system operating sub-modes were investigated. It is shown, that the electron sub-mode of system operation is characterized by an increased burning voltage, which is caused by the formation of a positive anode drop of more than 10 V in the plasmas. Such a potential distribution in the discharges ensures effective heating of the samples by the discharges plasmas electron component.
Formation of plasma jets by a high-current discharge in metal vapor
Authors: Kokshenev V A , Kurmaev N E 
Published: November 2021

Abstract
Plasma sources based on high-current discharges (up to 20 kA) in vapors of an aluminum electrode material with initiation over the ceramic surface are investigated. Plasma flows with a divergence angle ≤ 20° and a pulse pressure of ~ 106 Pa were obtained. A design of a crowbar spark gap based on a plasma switch with developed plasma sources built into a magnetically insulated transmission line has been proposed and tested. A crowbar mode is implemented in the transmission line with a current of a mega-ampere level with a cut-off of the load circuit from the megajoule generator GIT-12 for the period of discharge of the Marx generator.
On the scaling laws for low-temperature plasmas at macro and micro scales
Authors: Fu Y , Wang X , Zheng B , Zhang P , Fan Q H , Verboncoeur J P 
Published: November 2021

Abstract
The theoretical background and historical development of the similarity theory during the past decades are reviewed. We demonstrate similar discharges in local and nonlocal kinetic regimes, taking the low-pressure capacitive radio frequency (rf) discharges and microdischarges as examples. By using fully kinetic particle-in-cell simulations, we verify the similarity law (SL) and show a violation of frequency scaling (f-scaling) in the low-pressure capacitive rf plasmas. The similarity relations for electron density and electron power absorption are confirmed in similar rf discharges. With only the driving frequency varied, the f-scaling for electron density is also validated, showing almost the same trend as the similarity scaling, across most of the frequency regime. However, violations of the f-scaling are observed at lower frequencies, which are found to be relevant to the electron heating mode transition from stochastic to Ohmic heating. The scaling characteristics have also been comprehensively studied for microdischarges with dimensions from hundreds to several microns, with transition from secondary electron dominated regime to field emission regime. Finally, practical applications of the similarity and scaling laws are summarized.
Study of radiative characteristics of a completed partial discharge
Authors: Yakovlev E A , Yugay V V , Zinovyev L A , Kashlev A R , Bezrukov V O 
Published: November 2021

Abstract
The work is devoted to the study of the optical and electrical characteristics of a completed partial discharge burning in the presence of an electrolyte (1.5% NaCl solution). The possibility of using optical sensors that are part of smartphones such as Xiaomi for research is shown. The dependence of the radiation intensity of the completed partial discharge on the value of the ballast resistance in the discharge circuit and the material of the grounded electrode (anode) is studied. The dependence of the breakdown voltage on the size of the discharge gap is also studied. It is shown that it has a nonlinear character at a significantly lower (up to 20 times) breakdown voltage in comparison with the case of the absence of an electrolyte.
Structure and properties of high-chromium steel irradiated with a pulsed electron beam and nitrided in a low-pressure gas discharge plasma
Authors: Ivanov Y , Petrikova E , Teresov A , Lykov S , Tolkachev O , Rygina M 
Published: November 2021

Abstract
Ion-plasma saturation of the surface of machine parts and mechanisms with gas elements (nitrogen, oxygen, carbon) is currently one of the most effective and widely used methods of surface hardening of metal products for various purposes in the industry of developed countries. The aim of this research is to develop a complex method for modifying the surface layer of AISI 310 steel, combining irradiation with an intense pulsed electron beam and subsequent nitriding in the plasma of a low-pressure gas discharge. As a result of the studies performed, the optimal parameters of modification were revealed, which make it possible to increase the hardness of the surface layer of steel by more than 11 times, relative to the hardness of the initial material, and 8 times, relative to the hardness of steel irradiated with a pulsed electron beam. In this case, the wear resistance of the steel exceeds the wear resistance of the original and irradiated material by more than 100 times. It has been established that the high strength and tribological properties of the modified steel are due to the formation of a two-phase (iron nitride and chromium nitride) layered nanoscale structure in the surface layer.
Surface modification of hypereutectic silumin subjected to a millisecond modulated electron beam treatment
Authors: Ashurova K T , Vorobyov M S , Petrikova E A , Ivanov Yu F , Moskvin P V , Rygina M E 
Published: November 2021

Abstract
In this work, using a unique feature of the “SOLO” electron source with a grid plasma cathode based on a low-pressure arc discharge, which consists in the possibility of controlled operation of the beam power during a pulse of submillisecond duration, and, accordingly, the rate of energy input into the sample surface, we investigated the modes irradiation of samples of hypereutectic silumin. The irradiation modes had the same energy density during the first 200 μs of the pulse, equal to 20 J/cm2 and differed in different durations of further maintaining the surface temperature at 600°C for a time of up to 1 ms. The results of tribological tests and methods of diffraction microscopy of the investigated defect structure, the elemental and phase composition, the morphology of the strengthening phases of the modified layer of the hypereutectic silumin samples are presented.
Deposition of Al2O3 coatings in Ar-O2 low-pressure discharge plasma under a high dissociation degree of O2
Authors: Tretnikov P V , Gavrilov N V , Kamenetskikh A S , Krivoshapko S V , Chukin A V 
Published: November 2021

Abstract
The deposition of Al2O3 coating with a corundum structure was done by anodic evaporation in a low-pressure arc with a self-heated hollow cathode. The conditions were created for increasing the energy of plasma electrons and a corresponding increase in the frequency of O2 dissociation by contraction of the discharge in the anode region. The discharge was maintained in a combined mode with a constant current (70 – 100 A), on which current pulses (100 μs, 1 kHz) with adjustable amplitude (up to 220 A) were superimposed. This mode ensured a change in the degree of O2 dissociation in the range of 0.3 – 0.5 at constant average discharge current and Al evaporation rate. It is shown that an increase in the degree of O2 dissociation leads to an increase in the rate of coating deposition by a factor of 1.3 and promotion of the preferred (300) orientation of crystallites. The effect is due to the features of the adsorption of molecular and atomic oxygen on the Al2O3.
Features of boriding die steel D5 by electron beams
Authors: Milonov A S , Dasheev D E , Smirnyagina N N , Lapina A E 
Published: November 2021

Abstract
The microstructure and microhardness of the boride layers formed on die D5 steel by the methods of electron beam borating in vacuum under continuous and impulsive bunch modes are investigated and confronted. Formed layers have a heterogeneous structure, which combines solid and plastic components resulting in the fragility reduction of boride layer.
Investigation of tungsten surface carbidization under plasma irradiation
Authors: Miniyazov A Z , Skakov M K , Tulenbergenov T R , Sokolov I A , Zhanbolatova G K , Bukina O S , Kozhahmetov Ye A 
Published: November 2021

Abstract
This paper presents the results of studying the formation of a carbide layer under various experimental conditions and the choice of the optimal parameters for carbidization of the tungsten surface under plasma irradiation in methane. Therefore, to assess the effect of the surface temperature of a tungsten sample during experimental work, the surface temperature of the sample was 1300-1700°C, and to assess the effect of the irradiation time, a range within 300-2400 s was selected. From the results of X-ray phase analysis of the surface of tungsten samples, concluded that the temperature of the sample surface and the duration of irradiation have a significant effect on the formation of a carbidized layer on the tungsten surface during plasma irradiation on plasma-beam installation.
Formation of catalytic and corrosion protective layers with use of ion beam assisted deposition of metals from vacuum arc discharge plasma
Authors: Poplavsky V V , Dorozhko A V , Matys V G 
Published: November 2021

Abstract
This paper presents a brief overview of our studies on the modification of materials using ion beam assisted deposition (IBAD) of metals from vacuum arc discharge plasma in order to form catalytically active and corrosion-resistant layers on the surface. Deposition of metals on different materials with simultaneous mixing of the deposited layer with the substrate surface by accelerated ions of the deposited metal was carried out in an experimental setup with a pulsed electric arc ion source. Catalytic and corrosion properties of the materials with the obtained layers were studied using electrochemical voltammetric measurements. The microstructure and composition of the resulting layers were studied using the SEM, EDX, WD-XRF, XPS, EBSD, and RBS methods.
Effect of power of ultrasound during micro-arc oxidation on morphology, elemental and phase composition of calcium phosphate coatings
Authors: Kazantseva E A , Komarova E G 
Published: November 2021

Abstract
The effect of the magnitude of the US (ultrasound) power applied during the MAO (micro arc oxidation) process on the morphology, elemental and phase composition of the CaP coatings was studied. The US at different power (50-200 W) applying during the MAO process led to the local destruction of the structure elements (spheres and pores) and local filling the pore spaces on the coating surface, and to the formation of local macro-pores inside the coatings near the substrate. Such morphological transformations led to the surface and structure heterogeneity of the coatings, increasing of the surface roughness from 3.0 to 4.5 μm and of the thickness from 50 to 60 μm. The US application at different power did not affect significantly the elemental composition of the coatings. At the same time, under applied US with power more than 100 W, the state of the coatings transformed from X-ray amorphous to the quasiamorphous with the small incorporation of crystalline phases of CaHPO4 and β-Ca2P2O7.
Computer simulation of temperature fields in the Cr (film)-Zr (substrate) system during pulsed electron-beam irradiation
Authors: Markov A B , Solovyov A V , Yakovlev E V , Pesterev E A , Petrov V I , Slobodyan M S 
Published: November 2021

Abstract
The paper presents the results of numerical simulation of the distribution of thermal fields during the formation of Cr-Zr surface alloy using a pulsed low-energy high-current electron beam (LEHCEB). The melting thresholds of the Cr-Zr system for different thicknesses of Cr films were calculated. The melting threshold of the Cr-Zr system increases linearly with increasing Cr film thickness. A linear regression dependency model of the melting threshold on the film thickness is proposed. Evaporation thresholds of the Cr-Zr system for different thicknesses of Cr films were calculated. The evaporation threshold of the Cr-Zr system increases linearly with increasing Cr film thickness. A linear regression dependency model of the evaporation threshold on the film thickness is proposed. The value of the LEHCEB energy density at which the lifetime of the film and substrate are equal is calculated. This value is a maximum value for the effective formation of Cr-Zr. A model of the LEHCEB energy density, at which the lifetime of the film and the substrate are equal, in the form of a third-degree polynomial is proposed.
Field electron emission from a nanostructured tungsten surface
Authors: Mikhailov P S , Muzyukin I L 
Published: November 2021

Abstract
In this paper, the electron emission from a nanostructured tungsten surface was investigated. A method for measuring an extremely low current (10−12 – 10−14 A) has been tested. It made possible to reduce the effect of the electric field on the sample surface and to minimize the probability of spontaneous breakdowns. For a detailed study of tungsten fuzz, a point tungsten anode (diameter 90 μm) was used. Field enhancement factor (β = 2000 – 3000) and effective emission area were calculated using the Fowler–Nordheim plots. The pre-breakdown current rise was studied. The emission current waveforms suggest the formation of several emission structures before the breakdown.