Institute of Electrophysics UD RAS

Yekaterinburg, Russia

Institute of Electrophysics UD RAS

Yekaterinburg, Russia
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Rostov V.V.,Institute of High Current Electronics | Romanchenko I.V.,Institute of High Current Electronics | Pedos M.S.,Institute of Electrophysics UD RAS | Rukin S.N.,Institute of Electrophysics UD RAS | And 5 more authors.
Physics of Plasmas | Year: 2016

The generation of a 2-GW microwave superradiance (SR) pulses has been demonstrated at 29-GHz using a single-mode relativistic backward-wave oscillator possessing the beam-to-wave power conversion factor no worse than 100%. A record-breaking radiation power density in the slow-wave structure (SWS) of ∼1.5 GW/cm2 required the use of high guiding magnetic field (7 T) decreasing the beam losses to the SWS in strong rf fields. Despite the field strength at the SWS wall of 2 MV/cm, a single-pass transmission mode of a short SR pulse in the SWS allows one to obtain extremely high power density in subnanosecond time scale due to time delay in the development of the breakdown phenomena. © 2016 Author(s).


Rostov V.V.,Institute of High Current Electronics | Romanchenko I.V.,Institute of High Current Electronics | Elchaninov A.A.,Institute of High Current Electronics | Sharypov K.A.,Institute of Electrophysics UD RAS | And 3 more authors.
Physics of Plasmas | Year: 2016

Phase and frequency stability of electromagnetic oscillations in sub-gigawatt superradiance (SR) pulses generated by an extensive slow-wave structure of a relativistic Ka-band backward-wave oscillator were experimentally investigated. Data on the frequency tuning and radiation phase stability of SR pulses with a variation of the energy and current of electron beam were obtained. © 2016 Author(s).


Kurlyandskaya G.V.,University of the Basque Country | Kurlyandskaya G.V.,Ural Federal University | Fernandez E.,University of the Basque Country | Safronov A.P.,Ural Federal University | And 6 more authors.
Applied Physics Letters | Year: 2015

Thin-film based magnetoimpedance (MI) sensors were used for quantitative determination of the concentration of magnetic nanoparticles (MNPs) in ferrogels. Ferrogels (model systems for biological tissue) were synthesized by radical polymerization of acrylamide in a stable aqueous suspension of γ-Fe2O3 MNPs fabricated by laser target evaporation. MI [FeNi/Ti]3/Cu/[Ti/FeNi]3/Ti sensitive elements were prepared by sputtering. Thorough structural and magnetic studies of MNPs, ferrogels, and multilayered sensitive element insure the complete characterization of biosensor prototype. The MI response of the sensitive element was carefully evaluated in initial state and in the presence of ferrogels with different concentration of iron oxide MNPs from 0 to 2.44 wt. %, which produced systematic changes of the MI in a frequency span of 300 kHz to 400 MHz. © 2015 AIP Publishing LLC.


Safronov A.P.,Ural Federal University | Kurlyandskaya G.V.,University of the Basque Country | Bhagat S.M.,University of Maryland University College | Beketov I.V.,Institute of Electrophysics UD RAS | And 3 more authors.
Solid State Phenomena | Year: 2015

Spherical nickel nanoparticles were prepared by the electrical explosion of wire. The as prepared nanoparticles were modified immediately after fabrication at room temperature in order to provide tunable surface properties with focus on the development of composites filled with nanoparticles. Following liquid modificators were used: hexane, toluene and the solution of polystyrene in toluene. In one case the surface modification by carbon was made in gas phase as a result of hydrocarbon injection. The average size of the nanoparticles was about 50 nm and unit cell parameters were close to 0.351 nm. Detailed characterization was done by X-ray diffraction, transmission electron microscopy, and magnetization measurements. Sphericity was also checked using microwave resonant absorption. © (2015) Trans Tech Publications, Switzerland.


Yalandin M.I.,Institute of Electrophysics UD RAS | Mesyats G.A.,RAS Lebedev Physical Institute | Rostov V.V.,Institute of High Current Electronics | Sharypov K.A.,Institute of Electrophysics UD RAS | And 3 more authors.
Applied Physics Letters | Year: 2015

Real-time investigations of the dynamics of explosive electron emission from a high-voltage cathode holder made of nonmagnetic stainless steel in a magnetically insulated coaxial vacuum diode have been performed. It has been shown that aging the cathode with several tens of voltage pulses at a field of 1-2 MV/cm provides a stray emission delay ranging from hundreds of picoseconds to a nanosecond or more. In addition, the magnetic field must be configured so that the magnetic lines would not cross the vacuum gap between the diode case and the cathode holder in the region behind the emitting edge of the cathode. These efforts provide conditions for stable emission of the working beam from a graphite cathode with a sharp emitting edge. © 2015 AIP Publishing LLC.


Rostov V.V.,Institute of High Current Electronics | Elchaninov A.A.,Institute of High Current Electronics | Romanchenko I.V.,Institute of High Current Electronics | Yalandin M.I.,Institute of Electrophysics UD RAS
Applied Physics Letters | Year: 2012

A two-channel source of Cherenkov superradiance pulses with the electron-wave systems of identical geometry which is capable of producing 2 × 0.3 GW pulses of duration 2 ns and center frequency 10 GHz has been developed and explored. The channels are powered by a high-voltage driver whose pulse is split into two pulses that are sent through parallel transmission lines. To shorten the voltage rise time in each channel, identical NiZn ferrite-loaded coaxial transmission lines with independently controlled axial bias fields are used. © 2012 American Institute of Physics.


Sharypov K.A.,Institute of Electrophysics UD RAS | El'Chaninov A.A.,Institute of High Current Electronics | Mesyats G.A.,RAS Lebedev Physical Institute | Pedos M.S.,Institute of Electrophysics UD RAS | And 7 more authors.
Applied Physics Letters | Year: 2013

Coherent summation of microwave beams has been demonstrated for two superradiance Ka-band backward wave oscillators producing over 700 MW of power. The explosive emission cathodes of the e-beam injectors were powered by stable splitted voltage pulses produced by an all-solid-state modulator. The voltage fronts were shortened to 300 ps in controlled delay shock-excited ferrite lines. The standard deviation of the phase difference between the microwave pulses was less than 2% of the oscillations period. The power flux density of the summarized radiation was the same as that of a single generator producing an output power of ∼3 GW. © 2013 AIP Publishing LLC.


PubMed | RAS Institute of Continuous Media Mechanics, Russian Academy of Sciences, Institute of Electrophysics UD RAS, Perm State University and Perm National Research Polytechnic Institute
Type: | Journal: Materials science & engineering. C, Materials for biological applications | Year: 2016

The surface of elastic polyurethane treated by plasma immersion N2(+) ion implantation at different fluences has been investigated. A folded surface structure is observed in all cases. Analysis has been performed to study the structural (roughness, steepness and fraction of folds, fractal characteristics), mechanical (stiffness, adhesion force between the AFM probe and the material) and wetting properties of surfaces. Under uniaxial stretching the cracks orthogonal to the axis of deformation and longitudinal folds are formed on the examined surfaces. After unloading the initial structure of the surface of deformed materials exposed to low fluences becomes smoother and does not recover, i.e. it has plastic properties. By contrast, the structure of the surfaces of materials subjected to high-fluence treatment recovers without visible changes and the cracks are fully closed. The study of Staphylococcus colonies grown on these materials has demonstrated significant reduction (from 3 to 5 times) in the vitality of bacteria on treated surfaces. This result was repeated on samples after 11 months of storage. Such antibacterial properties are primarily related to the structural changes of the surfaces accompanied by the increased hydrophilicity.


Lyubutin S.K.,Institute of Electrophysics UD RAS | Pedos M.S.,Institute of Electrophysics UD RAS | Ponomarev A.V.,Institute of Electrophysics UD RAS | Rukin S.N.,Institute of Electrophysics UD RAS | And 3 more authors.
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2011

On the base of novel circuitry approach a SOS-based (Semiconductor Opening Switch) all-solid-state repetitive generator has been developed for various technological and industrial applications. The generator is equipped with a circuit for recuperation of unused energy reflected back from the magnetic compressor. The SOS is pumped in a novel pumping regime that includes microsecond forward pumping and current pause before fast reverse pumping process. As a result, the total efficiency of the generator has been increased from usual value of around 40% up to 60-62%. The generator has the following output specifications: peak voltage is up to 60 kV; peak current is up to 6 kA; FWHM is around 40 to 50 ns; pulse repetition frequency in continuous mode is up to 1 kHz; output average power in matched load is up to 9 kW. Electrical circuit diagrams and principle of the generator operation as well as experimental and testing results obtained are described. The results of numerical simulation of the SOS diode operation are presented also. © 2011 IEEE.


Osipov V.V.,Institute of Electrophysics UD RAS | Platonov V.V.,Institute of Electrophysics UD RAS | Lisenkov V.V.,Ural Federal University | Podkin A.V.,Institute of Electrophysics UD RAS | Zakharova E.E.,Ural Federal University
Physica Status Solidi (C) Current Topics in Solid State Physics | Year: 2013

The results of investigation of YSZ, Nd:Y2O3, Al2O3 nanopowder production by laser evaporation of oxide targets in a gas current are reported in present paper. For this purpose we used the pulse-periodical CO2 laser and the continuous fiber ytterbium laser with 550 W and 600 W radiation mean power accordingly. The powders obtained by these lasers, consisted of weakly agglomerated spherical nanopartices (≥ 99 wt%), and ≤ 1 wt% of micron sized particles (drops and target fragments). Nanoparticles from various oxides produced by CO2 laser in atmospheric pressure air had close average sizes (10÷16 nm). The productivity of nanopowder synthesis by CO2 laser from YSZ 1%Nd:Y2O3, 1%Nd:Y2O3, Al2O3, and CeGdO was 23 g/hour, 29 g/hour, 24 g/hour and 80 g/hour, respectively. Unlike CO2 laser the deep melting mode is realized during evaporation of 1%Nd:Y2O3 and Al2O3 targets by fiber laser. The crater depth increases up to 300-1000 μm in this mode. As a result, the target surface became very irregular and productivity of nanopowder synthesis was less, than in the case of CO2 laser. To reduce the effect of deep melting the evaporation of a target has been investigated experimentally and theoretically. As a result of our investigations we have obtained 1%Nd:Y2O3 nanopowder with specific surface of 70 m2/g and productivity of 23 g/hour at air pressure 70 kPa. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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