Исследование параметров самосфокусированного электронного пучка, выведенного за анод вакуумного диода

The parameters of a high-current electron beam extracted from the self-focusing zone through a hole in the anode into a vacuum chamber are investigated. The beam parameters were determined from the measurement of the spatial distribution of destruction and glow arising in polymethyl methacrylate samples installed at different distances from the anode (electron beam autographs). The formation of two electron beams - a self-focused with a high energy density, propagating along the axis of the cone facing the base to the anode with an apex angle of ~ 7º and a high-energy beam of low density, propagating in a hollow truncated cone and surrounding self-focused, was found. The oscillograms of the current and the energy of the electron beams were measured.

RADIATION STIMULATION OF THE CATALYTIC ACTIVITY OF ZIRCONIUM DIOXIDE NANOPARTICLES DURING THE CONVERSION OF HYDROCARBONS

The comparison of the catalytic activity of the initial and activated by bremsstrahlung -radiation on a high-current electron accelerator of zirconium dioxide nanoparticles on the nature of the conversion of ethanol. The used -activation parameters contributed to the formation of a more perfect crystal structure of ZrO2 nanoparticles. It was shown that when using -activated ZrO2 nanoparticles as a catalyst, the yield of hydrocarbon products during the conversion of ethanol was several times higher than the yield of the same products in the case of using the initial ZrO2 nanoparticles. The mechanism of such a conversion of ethanol can be associated with the synergism of large ionization losses of Auger electrons and the effect of highly reactive products involved in heterogeneous catalysis.

Modification of stainless steel based on synergistic of low-energy high-intensity ion implantation and high-current electron beam impact on the surface layer

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.

Formation of a Cr-Zr surface alloy using a low-energy high-current electron beam

The paper investigates the regularities of the formation of Cr-Zr surface alloy using a low-energy high-current electron beam (LEHCEB). The influence of the electron-beam processing parameters and the magnetron deposition parameters on the elemental composition of the formed Cr-Zr surface alloy is estimated. It is shown that, for all considered modes, there is a general tendency to a decrease in the chromium content in the surface alloy with an increase in the energy density or the LEHCEB processing pulse number. The thickness increasement of the chromium film applied in one cycle or the surface alloy total thickness increasement leads to an increase in the chromium content in the surface alloy. The LEHCEB processing parameters, namely the energy density and the number of pulses, have a greater effect on the chromium content during the formation of the Cr-Zr surface alloy in comparison to the magnetron sputtering parameters, namely the deposited film thickness and the formed surface alloy thickness. A linear regression model that describes the chromium content in the surface alloy depending on the film thickness, the surface alloy total thickness, the number of pulses and the pulse energy density is proposed.

Synthesis and Characterization of Ti–Nb Alloy Films Obtained by Magnetron Sputtering and Low-Energy High-Current Electron Beam Treatment

The aim of the present work is to investigate the synthesis of Ti–Nb alloy films obtained by the physical vapor deposition (PVD) magnetron sputtering of Nb films on Ti substrates, followed by low-energy high-current electron beam (LEHCEB) alloying treatment. Ti–Nb alloys were synthetized under two different regimes, one by varying the deposited amount of Nb (from 25 to 150 nm) and treating samples with low applied voltages and a number of pulses (three pulses at either 20 or 25 kV), the second by setting the amount of Nb (100 nm) and alloying it at a higher applied voltage with a different number of pulses (from 10 to 50 at 25 and 30 kV). The synthetized Ti–Nb alloys were characterized by XRD and GDOES for phase identification and chemical composition; SEM and optical microscopy were employed for morphology evaluation; compositional investigation was done by EDS analysis and mechanical properties were evaluated by microindentation tests. LEHCEB treatment led to the formation of metastable phases (α′, α″ and β) which, together with the grain refinement effect, was responsible for improved mechanical properties.