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The stability of operation of an electron source with a plasma cathode with grid (layer) stabilization of the emission-plasma boundary and a plasma anode, whose boundary is open, is investigated. An increase in the stability of the source operation is achieved by reducing the reverse gas and ion flows, when the electron-beam trajectory changes due to the placement of the emission electrode of the electron source and a target in different planes. Calorimetric measurements of the radial distribution of the energy density of the generated electron beam were carried out under the conditions of its deflection and in the “straight” transport mode, when the collector target is on the line of sight relative to the emission electrode. It has been experimentally shown that the stability of the electron-source operation increases by several times when the beam is deflected, thus making it possible to expand the range of the beam parameters and opening up new possibilities for using such an electron source for scientific and technological purposes.

The paper presents the results of studies of processes of generation of a beam-plasma formation in an extended cylindrical hollow mesh anode with a diameter of 115 mm and a length of about 1 m of a non-self-sustaining low-pressure arc discharge with thermionic and hollow cathodes. The probe method was used to measure the longitudinal distributions of the plasma parameters inside the mesh hollow anode of the arc discharge for burning conditions with/without a flow of ions injected from the plasma of the main glow discharge, for which the hollow anode was the plasma emitter of electrons. The distributions of the ion current density on the probe inside the cylindrical anode of the arc discharge (electron emitter) as functions of the operating pressure, the longitudinal magnetic field in the hollow cathode of the arc plasma source, and the arc discharge current are experimentally determined. In an extended plasma emitter, unequal conditions of plasma formation are formed, leading to the formation of a potential barrier for the propagation of the arc plasma. The emission of ions from the glow discharge plasma in the beam-plasma formation allows the inhomogeneity of the plasma formed in the hollow plasma emitter to be reduced significantly. The results obtained show the possibility of forming relatively uniform extended beam-plasma formations inside the extended mesh anode of the arc discharge under conditions of injection of an external ion flow through the mesh cells.

Operational principles and main characteristics of electron sources based on plasma emitters with grid/layer stabilization of the boundary of the emission plasma generated by low-pressure discharges are described. The achieved levels of the parameters and the prospects for future development of the electron sources intended for generation of pulsed high-density (with energy density up to 100 J/cm2 per pulse) low-energy (5–25 keV, 50– 500 A) and high-energy high-current (up to 100 keV, $$ \tilde{>} $$ 1 kA) electron beams in vacuum with beam energy content up to 5 kJ, pulse frequency (30 μs, 50 s–1), large beam cross section $$ \left(\tilde{>}\ 1000\ {\mathrm{cm}}^2\right), $$ electron energy up to 250 keV, and current up to 100 A extracted into the ambient atmosphere through an output foil window are considered. The special features of emission plasma generation by low-pressure arc discharges in plasma grid emitters and of electron output from it, the special features of the discharge system of plasma emitters partially immersed into an inhomogeneous magnetic field, and the special features of the formation and transportation of high-density low-energy electron beams in a longitudinal magnetic field are considered. The application field of the electron sources with plasma grid emitters and the processes and technologies implemented with their use are indicated.

The aim of the research is to elucidate the patterns of modification of the elemental and phase composition, defective substructure, and mechanical and tribological properties of a carbon steel during a combined treatment in a single vacuum cycle, including deposition of niobium and silicon films on the steel surface and irradiation of the film/substrate system with an intense pulsed electron beam. The formation in a single vacuum cycle of Si–Nb films 1 μm thick each on the 40Cr steel specimens was carried out on the COMPLEX setup by the magnetron (Si) and arc evaporation (Nb) methods with plasma assistance. High-speed melting of the (Si–Nb) film/(40Cr steel) substrate system was carried out by an intense pulsed electron beam. The mode of irradiation of the (Si + Nb) film/(40Cr steel) substrate system by an intense pulsed electron beam (50 J/cm2, 200 μs, and 3 pulses) is revealed that allows the formation of the surface layer characterized by the high hardness equal to 9600 MPa (exceeding the hardness of the 40Cr steel in the initial (ferrite-perlite) state by a factor of 3.3) and the wear resistance that exceeds by more than 15 times the wear resistance of the 40Cr steel in the initial state. It has been shown that high strength and tribological properties of the steel are due to the formation of particles of the strengthening phase (Nb5Si3, Nb3.61Si0.39, Nb08Fe02, SiC, and NbO2) and a relatively large (up to 30 μm) thickness of the strengthened layer.

A one-dimensional model of a hard alloy is proposed, which takes into account the heterogeneity of the physical properties of a composite material by representing it as a sequence of 2 μm TiC and WC carbide particles. The influence of the energy density of pulsed high-current electron beams on the melted layer depth and microstructure is investigated. A comparison of the penetration depths of the hard alloy obtained by calculation and experimentally shows their good agreement. It is found out that with an increase in the beam energy density due to melting of the carbides a (Ti, W)C supersaturated tungsten solid solution is formed and a WC→W2C transformation occurs during crystallization.

The paper presents the features of the «SOLO» electron source operation with a grid plasma cathode, the operation principle of which is based on the use of a fine-mesh grid that stabilizes the boundary of the emission plasma. The grid (layer) stabilization of the emission plasma boundary allows the generation of electron beams with a wide range of parameters, which weakly depend on each other, and which makes it possible to control any of the electron beam parameters separately (electron energy, current amplitude discharge, the duration and frequency of the pulse current beam), keeping the other beam parameters unchanged. Thus, the SOLO source allows the generation of wide (up to several cm 2 ) low-energy (up to 25 keV) intense (hundreds of amperes) submillisecond electron beams and use these beams in vacuum to modify the surface of various inorganic materials (an energy density reaches 100 J/cm 2 ). In this work, an important distinctive feature of such an electron source will be demonstrated, namely, the ability to controllably generate an electron beam with variable power during a pulse of submillisecond beam duration by changing its amplitude. In a number of cases, this feature provides conditions for a more stable operation of the electron source, which makes it possible to introduce more energy into the sample surface, as well as to controllably change the surface temperature of the irradiated sample. In particular, it is possible to keeping the surface temperature of the irradiated sample in the millisecond range, which opens up additional possibilities when using such electron sources both for scientific (for example, thermonuclear materials science) and for technological purposes (for example, for increasing the service life of various units and mechanisms).

The principle of operation and major characteristics of a laboratory setup designed for electron-ion-plasma surface modification of materials and parts in a single vacuum cycle are presented. Using an Al–Ti system as an example, a possibility of a multiple improvement of mechanical (microhardness) and tribological (wear resistance and friction coefficient) properties of a material formed as a result of a comprehensive treatment in a single vacuum cycle, combining the formation of an A7 technical-grade aluminum surface layer alloyed with titanium via a deposition – irradiation scheme (number of cycles from 1 to 20; metal film thickness per cycle 0.5 and 1 μm) followed by a subsequent electron-ion nitriding (540°С, 8 h) of the resulting surface alloy in the plasma of a non-self-sustained discharge by the ion and electron plasma components is demonstrated.

The results of investigation of the influence of geometrical dimensions, shape and position of the anode of a high-current non-self-sustained glow discharge with a hollow cathode at low (≈1 Pa) pressure with the current up to 100 A on the degree of inhomogeneity of azimuthal plasma-concentration distributions are presented. The azimuthal measurements demonstrate that upon injection of an electron flow with the current exceeding that of the electrons, formed as a result of the secondary ion-electron emission, the value of the average path length L of electrons before their escape to the anode is much lower than that in a self-sustained discharge burning mode. It is determined that in the case of injection of an electron flow into the hollow-cathode glow discharge the anode position considerably affects the degree of plasma concentration inhomogeneity. It is shown that placing the annular anode in the site preventing the line-of-site between the electron injection and anode surface directions allows achieving the minimum inhomogeneity coefficient value.

Designs are presented for plasma grid cathodes based on an arc contracted discharge. They are designed to work under conditions of an inhomogeneous magnetic field as high as 35 mT and penetrate into their gas-discharge system from the region of electron beam transport. Parameters are presented of the electronic source used to modify the surfaces of materials and products using a pulsed electron beam in order to alter their operating properties.

The local temperatures on the surface of a ceramic coating – aluminum substrate system are measured during its irradiation with a submillisecond pulsed electron beam. Certain parameters, such as electron beam density, pulse duration, and thickness of a TiCuN-coating, are varied. The optimal modes for electron beam irradiation of the TiCuN-coating – А7-substrate system are identified.

The results of investigations of low-voltage burning modes of a non-self-sustained glow discharge with a ~0.2 m3 hollow cathode at low (≈1 Pa) pressure, which is assisted by an external injection of electrons from the electric-arc plasma. The current-voltage characteristics recorded at low burning voltages 20–80 V demonstrate that there is a threshold glow-discharge burning voltage, at which a stepwise transition takes place from the burning conditions with high plasma inhomogeneity to the conditions of homogeneous plasma glow in the entire volume of the hollow cathode. This transition, accompanied by an enhanced hollow-cathode effect, is characterized by a 20–40% increase in the main discharge current. The glow discharge burning voltage, at which this current jump takes place lies within the range 45–60 V and depends on the value of the auxiliary discharge current and working pressure.

The results of investigation of pulsed burning modes of a non-self-sustained arc discharge with a combined hot-and-hollow cathode are presented. The principal discharge characteristics are measured at the currents up to 350 A and discharge burning voltages up to 200 V within the working pressure range 0.2–1 Pa. It is shown that an increase in the working pressure gives rise to an increase in the discharge current as a result of gas amplification, resulting from an improvement in the processes of fast electron energy utilization during gas ionization. The maximum resulting discharge current in a nitrogen atmosphere at a pressure of 0.8 Pa is found to be 550 A at the discharge burning voltage up to 200 V and the maximum pulsed power up to 80 kV. The concentration of plasma in the center of the ≈0.2 m3 chamber is found to be about 4·1017 m–3 at the density of the ion current from plasma approximately 6.5 mA/cm2 and the discharge pulsed power 18 kW.

—In an electron source with a mesh plasma cathode on the basis of a low-pressure arc discharge, studies of the spatiotemporal stability of a pulse–periodic beam with a large cross section (750 × 150 mm2), which was extracted into the atmosphere through an output foil window, were performed. The automated system that was used in the studies allowed real-time measurements with the ability to visualize the data on a computer. This system provides an accuracy of measurements of no worse than ±2%; it differs from the known analogues in the compactness, reliability, and simplicity of its design and allows studies of the current-density distribution over the beam cross section in a wide range of beam parameters, such as the beam energy, beam current, and beam-current pulse duration. A satisfactory coincidence of the previously obtained data and the present experimental data is shown with the possibility of substantially increasing the accuracy of setting up a scientific experiment and, consequently, the speed of debugging and the reproducibility of the technological process.

This paper presents the results of low-energy high-current implantation of nitrogen ions into AISI 5140 steel. The plasma was generated using a plasma source based on non-self-sustained arc discharge, using thermionic and hollow cathodes. The influence of the temperature of the specimens and irradiation dose on the characteristics of the ion-modified layer was studied. The temperature of the specimens was controlled within the range of (450–650) °C by changing the duty factor of the bias pulse and the average ion current density. The microhardness of the steel after 1-hour of low-energy high-current implantation of nitrogen ions increased almost 2-fold (up to 7100 MPa), and a modified layer with a thickness up to 200 μm was formed. The wear resistance increased 7.5-fold. The main factor determining the efficiency of nitrogen dopant penetration was the temperature of the specimen. The parameters of the ion treatment influence the shape of the hardness distribution profile and the efficiency of ion cleaning of the surface.

This paper describes the optimal modes of initiation of self-propagating hightemperature synthesis with the help of an electron beam on the example of a Ti–Al–C powder mixture. A pulsed electron beam with a particle energy of tens of kiloelectronvolts and a duration of hundreds of microseconds is used. Morphology, structure, and elemental composition of formed products in the form of Ti3AlC2 and TiC are studied.

The description and the main characteristics of the pulsed electron source “SOLO” developed on the basis of the plasma cathode with grid stabilization of the emission plasma boundary are presented. Тhe emission plasma is generated by a low-pressure arc discharge, and that allows to form the dense low-energy electron beam with a wide range of independently adjustable parameters of beam current pulses (pulse duration of 20–250 μs, pulse repetition rate of 1–10 s–1, amplitude of beam current pulses of 20–300 A, and energy of beam electrons of 5–25 keV). Тhe special features of generation of emission plasma by constricted low-pressure arc discharge in the grid plasma cathode partially dipped into a non-uniform magnetic field and of formation and transportation of the electron beam in a longitudinal magnetic field are considered. The application area of the electron source and technologies realized with its help are specified.

This paper is focused on a clarification and analysis of the regularities of formation of the structure and properties of samples of the titanium-based alloy VT6, obtained by methods of conventional metallurgy and formed by layered selective electron-beam sintering in vacuum (using the Arcam A2X (3D printer) system (Arcam, Sweden)) of VT6 titanium powder with particle size 40–100 μm. Additional modification of the samples was realized by irradiating the surface with an intense pulsed electron beam (15 keV, 45 J/cm2, 200 μs, 10 pulses, 0.3 s–1, 3.5·10–2 Pa). It is shown that the action of a pulsed electron beam on the surface of samples formed by layered selective electron-beam sintering leads to a significant reduction in the porosity of the surface layer of the material and formation in the surface layer of a polycrystalline structure (grain size 15–60 μm) with a substructure in the form of crystallization cells (cell size 0.5–1.2 μm). Electron-beam processing of samples prepared by methods of conventional metallurgy for the indicated electron-beam parameters leads to the formation in the surface layer of a polycrystalline structure (grain size 50–800 μm) with a laminar intragrain substructure. Mechanical tests, performed by stretching flat samples, showed that the highest combination of mechanical strength and plasticity is possessed by samples obtained by layered selective electron-beam sintering with subsequent irradiation by an intense pulsed electron beam.

The limiting parameters of an intense sub-millisecond electron beam generated in the source with a plasma cathode on the basis of a low-pressure multi-arc discharge with mesh stabilization of the cathode (emission) plasma boundary and mobile anode (beam) plasma boundary are investigated. It is demonstrated that the limiting parameters of the electron beam in the examined electrode system are limited by its energy content on a level of about 4 kJ the excess of which leads to an electric breakdown of the accelerating gap. The optimal pressures are determined at which the beam during its transportation in the longitudinal magnetic field with a preset configuration has maximal parameters for the given electrode system. Different mechanisms of electric breakdown initiation and methods for increasing the electric strength of the high-voltage accelerating gap in this electrode system are discussed.

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).

This work represents the investigations for decreasing acceleration gap breakdown probability of plasma source of electrons SOLO, with grid stabilization of the boundaries of the arc cathode plasma. We increased the distance to the treated target, bent the transportation channel of the electron beam, created additional plasma in the anode space, and increased the beam front. The effect of the above measures on the breakdown probability when the target is exposed of a low-energy electron beam with a power density of up to 0.5 MW/cm2 with a diameter of 2.5 cm was investigated separately. Beam deflection is most effective at relatively long pulse durations of 150 μs and accelerating voltage of 20 kV, rather than a lower one. It was possible to double the maximum power for the same beam transport length applied to a low-melting target. Preionization in the anode proved to be effective for relatively short beams of 15 μs duration.

The use of a modern element base makes it possible to create power supplies with a transition from a direct mode of generation of an auxiliary discharge to a pulse-periodic mode with a pulse repetition rate at the level of several tens of kHz. This allows for a more flexible adjustment of the discharge parameters, keeping the average value of its current, but changing its amplitude with a corresponding change in the pulse duty cycle. In this work, using an electron accelerator based on ion-electron emission, generating a wide-aperture electron beam, we research the effect of auxiliary discharge generation mode (direct and pulse-periodic) on the efficiency of electron beam extraction into the ambient atmosphere. It is shown that, in a direct mode of electron beam generation at an accelerating voltage of 150 kV, the beam extraction coefficient does not exceed 0.25. The possibility of increasing the extraction coefficient to K = 0.55 at the same accelerating voltage of 150 kV was demonstrated without making changes to the design of the accelerator, but switching to a pulsed-periodic mode of emission plasma generation.

This paper presents the results of studying the stability of the plasma emitter of an electron accelerator based on ion-electron emission during the transition from self-sustained continuous to self-sustained frequency (up to 50 kHz) repetitively pulsed generation of an auxiliary glow discharge with a hollow cathode with an area of 20.8×103 cm2 The experimental dependences of the probability of the appearance of cathode spots on the walls of a hollow cathode per unit time on the operating modes of the plasma emitter (pressure and type of working gas, amplitude of the auxiliary discharge current) are presented.

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.

In a plasma-cathode electron source with a grid-stabilized emission boundary, a discharge in crossed fields was used to create an auxiliary anode plasma before the generation of an electron beam. Such a plasma formed in the beam transport region shortens the rise time of the beam current and eliminates or at least minimizes its high-frequency oscillations at low pressures, making possible electron beams of several microseconds long and stable lower-pressure modes with less probable acceleration gap breakdowns. These effects are explained primarily by gas pre-ionization in the beam acceleration and transport region and by ion flows from the acceleration gap to the plasma cathode of the source.

The paper presents a COMPLEX laboratory setup for surface engineering, describes its components and principle of operation, and provides experimental data on its use for treatment of commercially pure VT1-0 titanium. The setup comprises gas and metal plasma generators based on a low-pressure arc discharge and a pulsed plasma-cathode electron source, allowing complex treatment of materials through nitriding in low-pressure arc plasma and subsequent TiN coating deposition in a single vacuum cycle. The experimental data demonstrate that such complex surface modification decreases the friction coefficient of VT1-0 titanium 1.3 times and increases its wear resistance more than 30 times.

The paper reports on a comparative study of two different types of diode system for producing intense submillisecond electron beam in a source with low-pressure arc plasma emitter. The first is a planar multi-aperture diode comprising cathode and anode performed as molybdenum grids with 241 round openings of few millimeters in diameter. In the second system electrons are accelerated in a sheath between the grid-stabilized cathode plasma and the open boundary of beam-generated anode plasma. It was demonstrated in experiments that latter system should be advantageous in terms of maximally achievable beam current and total beam energy content, but there are drawbacks connected with slow anode plasma build-up that require further study.

Using the probe technique, a comparative analysis of parameters of the gas-metal plasma generated by low-pressure discharges is performed during variation of their main characteristics. It is shown that by varying the discharge current of the gas plasma source it is possible to readily change the fraction of gas ions in the gas-metal plasma generated by the arc evaporator and the gas plasma source with thermionic and hollow cathodes. In the case of nitride coatings, it is found out that the concentration of nitrogen in the coatings formed by the vacuum-arc plasma-assisted deposition increases, without any changes in the nitrogen working pressure. Using the coatings based on the Mo–N and Ti–N systems as examples, a twofold increase in the nitrogen concentration is shown as the ion current density of the gas plasma source increases by a factor of three in comparison with the modes without using this source. The method discussed in this study exhibits lower inertia compared to the traditional gas pressure variation.

This work shows the possibility in principle of forming hydrocarbon structures in polyvinyl chloride films free of admixtures and polyvinyl chloride films modified with 5-mass % ferrocene via a radiation chemical transformation in the atmosphere with the use of an electron accelerator with a plasma cathode operating in the pulsed-periodic mode maximal electron energy no higher than 160 keV, pulse length of 40 μs, and current density of 5 mA/cm2. According to the results of semiquantitative X-ray microanalysis, an irradiated polyvinyl chloride film free of admixtures contains 92 of carbon, 6 of oxygen, and 2 mass % of chlorine; the irradiated polyvinyl chloride is an amorphous carbon material. A possible mechanism of the phenomenon is discussed.

Numerical simulation of the thermal processes that occur during doping of an Al surface with titanium by the method of liquid-phase mixing of a film–substrate system using an intense pulsed electron beam is carried out. As a result of our studies, it is shown that melting of the Ti-film–Al-substrate system makes it possible to form a multiphase submicrocrystalline structure with high strength and tribological properties in the surface layer.

The study demonstrates the possibility of predicting the energy spectrum of a wide-aperture (750 × 150 mm) electron beam outputted into ambient air through a thin metal foil on an electron accelerator with a grid plasma cathode. This type of accelerators features a weak mutual dependence of the electron beam parameters (electron energy, beam current, pulse duration, repetition frequency), and the beam spectrum can be reconstructed using experimental attenuation curves of the beam current through thin metal foils and the Tikhonov regularization with minimum a priory assumptions. Such spectra reconstructed for different accelerating voltages (110–160 keV)are presented, and research data are reported suggesting that the beam energy spectrum depends only slightly on the operating gas pressure and that it broadens mostly due to scattering of the beam in the output foil and in ambient air. Decreasing the accelerating voltage during a beam current pulse provides predictable broadening of the beam energy spectrum with a shift of its peak toward the lower energy, and this can be valuable for efficient use of such accelerators both in science and technology.

The results of investigating the emission properties of a multiaperture plasma emitter with grid stabilization of the emission-plasma boundary in an electron source with ejection of a generated electron beam from the accelerating gap into the atmosphere through a thin foil. A stainless-steel foil mask with 344 circular holes is laid on an emission grid with dimensions of 750 × 150 mm. The holes form a discrete emission structure of the plasma emitter, from which electrons are emitted under the action of an accelerating voltage. The alignment of the holes in the mask of the emission structure and in the bearing grid of the output foil window, which has the same number of holes with a larger diameter, and the attainment of a coaxial plane–parallel geometry of the accelerating gap allows minimization of the beam loss in the bearing grid of the output foil window. An electron beam is a superposition of elementary beams that are formed by individual emission structures, whose plasma boundaries are stabilized with a fine-structure metal grid. The coefficient of the current extraction into the atmosphere reached 75% of the emission current. In experiments at an accelerating voltage of 200 kV, an emission current of 16 A, and a pulse duration (FWHM) of 40 μs, a beam with an average power of ∼4 kW was ejected into the atmosphere. This value is more than 60% of the beam power in the accelerating gap at a geometrical transparency of the bearing grid of the output foil window of 56%. A further increase in the power was limited by the power of the high-voltage power-supply unit.

In this paper, the spectra of electron beams produced in vacuum and gas diodes were analyzed to study the capabilities and limitations of their reconstruction from beam attenuation in foils of different thickness. The electron energy distributions were calculated using the Tikhonov regularization for Fredholm integral equations on minimum a priori assumptions. The spectra reconstructed in the study were those of electron beams, including a supershort avalanche electron beam, produced in experiments on a DUET plasma-cathode electron accelerator and SLEP-150M accelerator.

The design of the device and procedure of measuring the effective secondary emission coefficient γeff in glow discharges with a large-area cathode are described. The values of γeff and the density of the ion current on the cathode in the self-sustained and nonself-sustained (under the additional external injection of electrons) discharge burning modes are determined. It is shown that for the self-sustained burning mode of the basic discharge with a current of 30 A, the value γeff ≈ 0.15, being in good agreement with both the theoretically calculated and known reference data. When the basic discharge occurs in the nonself-sustained mode, γeff = 0.08–0.12, depending on the discharge burning voltage, and the ion current density on the cathode surface is equal to 0.8–1.1 mA/cm2, being ≈10% lower than the value characteristic of the self-sustained discharge mode.

An electron accelerator with a multiaperture plasma cathode with grid stabilization of the boundary of emission plasma based on a low-pressure arc discharge generating a large cross-section (750 × 150 mm2) beam with its ejection into the atmosphere or high-pressure gas through the exit foil window is described. A comparatively simple method for decreasing the nonuniformity of the current density distribution over the beam cross section using a mask with variable-diameter holes is proposed and experimentally tested. In this case, the higher the plasma concentration in the emission region, the smaller the diameter of the holes in the mask. When this mask was used, the nonuniformity of the current density distribution was decreased from ±15 and ±10% to ±10 and ±5% on the long and short sides of the beam cross section, respectively.