N. N. Koval

ORCID: 0000-0001-5339-7994
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About
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Research Areas
  • Metal and Thin Film Mechanics
  • Plasma Diagnostics and Applications
  • Pulsed Power Technology Applications
  • Plasma Applications and Diagnostics
  • Vacuum and Plasma Arcs
  • Laser Design and Applications
  • Diamond and Carbon-based Materials Research
  • Ion-surface interactions and analysis
  • High-Temperature Coating Behaviors
  • Advanced materials and composites
  • Surface Treatment and Coatings
  • Advanced Sensor Technologies Research
  • High Entropy Alloys Studies
  • Gyrotron and Vacuum Electronics Research
  • Advanced Materials Characterization Techniques
  • Advanced Surface Polishing Techniques
  • Material Properties and Applications
  • Additive Manufacturing Materials and Processes
  • Laser Material Processing Techniques
  • Laser-induced spectroscopy and plasma
  • Titanium Alloys Microstructure and Properties
  • Solid State Laser Technologies
  • Metal Alloys Wear and Properties
  • Intermetallics and Advanced Alloy Properties
  • Integrated Circuits and Semiconductor Failure Analysis

Institute of High Current Electronics
2015-2024

National Research Tomsk State University
2012-2022

Don State Technical University
2022

Institute of Service and Entrepreneurship of DGTU
2022

Siberian Branch of the Russian Academy of Sciences
2011-2021

Plasma (Russia)
2018-2021

Tomsk Polytechnic University
2012-2019

Russian Academy of Sciences
2005-2016

United States Air Force Academy
2006-2007

Tomsk Institute of Economics and Law
2004

The review relates to low-pressure discharges with a hollow cathode and anode. term 'low pressure' implies that neutral particle density is extremely small the electron free path for ionization in excess of characteristic size discharge gap. On other hand, particles still play an essential role forming gas-discharge plasma. Thus, regimes keep intermediate position between classical avalanche pure vacuum burns metal vapor. New approaches interpretation formation mechanism at stage delay time...

10.1088/1361-6463/aacf10 article EN Journal of Physics D Applied Physics 2018-07-13

The effect of the intensification electron emission in a plasma-cathode diode with grid-stabilized plasma boundary has been investigated. For pulsed (100-mus) beam 15-20-keV energy that passes through formed as result gas ionization by an beam, it revealed increase pressure increases current at fixed discharge current, and can become greater magnitude than current. It shown significant electron-beam is provided secondary ion-electron results from bombardment electrode surface accelerated...

10.1109/tps.2009.2023412 article EN IEEE Transactions on Plasma Science 2009-06-25

Silicate-containing hydroxyapatite-based coatings with different structure and calcium/phosphate ratios were prepared by radio-frequency magnetron sputtering on silicon titanium substrates, respectively. Scanning electron microscopy, X-ray diffraction IR spectroscopy used to investigate the effect of substrate bias properties silicate-containing coatings. The deposition rate, composition, microstructure deposited all controlled changing voltage from grounded (0 V) −50 −100 V....

10.1039/c3ra40446c article EN RSC Advances 2013-01-01

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

10.1017/s0263034615000324 article EN Laser and Particle Beams 2015-03-20

High-current pulsed electron-beam (PEB) treatment was applied as a surface finishing procedure for Ti–35Nb–7Zr–5Ta (TNZT) alloy produced by electron beam melting (EBM). According to the XRD results TNZT samples before and after PEB have shown mainly single body-centered cubic (bcc) β-phase microstructures. The crystallite size, dislocation density, microstrain remain unchanged treatment. investigation of texture coefficient at different grazing angle revealed evolution orientations re-melted...

10.3390/met11071066 article EN cc-by Metals 2021-07-01

High-current electron beams with a current density of up to 100 A/cm 2 generated by plasma-cathode gas-filled diode at low accelerating voltages are studied. Two types gas discharges used produce plasma in the cathode. With glow and arc discharges, beam currents 150 A 400 A, respectively, have been obtained an voltage 16 kV pressure 1–3·10 −2 Pa acceleration gap. The ions resulting from ionization molecules electrons neutralize charge. charge-neutralized almost without losses is transported...

10.1017/s026303460321212x article EN Laser and Particle Beams 2003-04-01

The performance capabilities of the PINK, a plasma generator with thermionic cathode mounted in cavity hollow cathode, depending for its operation on non-self-sustained low-pressure gas discharge have been investigated. It has shown that when single-filament tungsten 2 mm diameter is used and peak filament current equal to or higher than 100 A, self-magnetic field significantly affects voltage waveforms. This effect due changes time space distributions emission density from hot cathode. When...

10.1063/1.4932543 article EN Review of Scientific Instruments 2015-10-01

The paper considers a plasma source based on low-pressure (≈1 Pa) high-current (up to 450 A) non-self-sustained glow discharge with hollow cathode of volume ≈0.2 m3. research data are presented the ignition stability discharge, its main parameters, and radial azimuthal inhomogeneity varying pressure, voltage current, anode-to-cathode area ratio at density ≈1018 m−3 an ionization degree ≈1%. beam formations synthesized in such electrode system interesting both from scientific technical point view.

10.1063/1.5126485 article EN Physics of Plasmas 2019-12-01

10.1016/0168-9002(92)90049-a article EN Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 1992-10-01
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