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We have performed a comparative numerical analysis of two methods for reducing the runaway electron beam divergence using an external magnetic field or a dielectric tube. The generation of runaway electrons takes place in an inhomogeneous medium that consists of a hot channel (spark channel, laser torch, etc.) surrounded by air under normal conditions. The model makes it possible to consistently calculate the formation of a subnanosecond gas discharge and the generation of accelerated electrons under these conditions. The possibility of effectively decreasing the runaway electron beam divergence using an external magnetic field, as well as a dielectric tube, has been demonstrated. However, the number of runaway electrons in the case with the tube is considerably smaller than in the case with the magnetic field due to the fact that some runaway electrons settle on the tube walls. The energy spectra of the runaway electrons significantly differ in these cases, which can be explained by the differences in the dynamics of the discharge formation. 相似文献
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Technical Physics - The formation of the cathode layer of a self-sustained high-pressure space discharge with preliminary ionization of a gas medium, excited by nano- and subnanosecond voltage... 相似文献
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I. S. Abramov V. A. Andreev V. T. Barchenko A. V. Gusev A. A. Lisenkov 《Russian Physics Journal》1994,37(3):300-308
Results obtained when investigating the possibility of using an Ardenne duoplasmatron as a generator of a highly ionized plasma beam containing ions of dielectric materials for depositing resistive films in a vacuum are presented. The constructional features of the duoplasmatron are considered, and information on the parameters of the plasma reactor of the evaporator is presented. The rate of deposition of films is investigated experimentally as a function of the modes of operation of the duoplasmatron. The properties of the films obtained are discussed. Methods of controlling the parameters of the highly ionized plasma fluxes which ensure a change in the velocity vector of the flux, its density, and the percentage content of the drop phase in it are considered.St. Petersburg Electrical Engineering State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 121–131, March, 1994. 相似文献
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A new class of non-carbon nanotubes based on Group III and Group V elements (aluminum and phosphorus, respectively) is considered. The equilibrium geometry, energy characteristics, and electronic structure of the AlP nanotubes were calculated using the density functional theory. These calculations demonstrated that the AlP nanotubes are energetically stable structures. It was found that a low strain energy (approximately 0.01–0.07 eV) is required for rolling a two-dimensional hexagonal AlP structure into a tube. The AlP nanotubes are found to be wide-band-gap semiconductors with a band gap of 2.05–3.73 eV with direct (for the zigzag type) or indirect (for the armchair type) transitions between the top of the valence band and the bottom of the conduction band. The band gap of these nanotubes increases with the tube diameter, approaching the band gap of a two-dimensional hexagonal AlP layer. 相似文献
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Osipov V. V. Solomonov V. I. Spirina A. V. Lisenkov V. V. Platonov V. V. Podkin A. V. 《Optics and Spectroscopy》2017,122(1):155-161
Optics and Spectroscopy - The spectra of luminescence of plumes that occur near targets of Nd: Y2O3, YSZ, and Al2O3 when they are irradiated by pulses of a ytterbium fiber laser with a wavelength... 相似文献
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Using first-principles calculations, we demonstrate the existence of anisotropic ferromagnetic interactions in Co embedded graphene nanoribbons (GNRs). Spin polarization of the edge states is found to alter significantly compared to the metal-free cases. Our findings can all be well-justified as the output of the interplay between the development of an induced spin polarization in the neighborhood of the Co atoms and the maintaining of the polarization picture of the Co-free GNR. Based on our results, we propose an efficient pathway for graphene-based spintronics applications. 相似文献
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V. V. Osipov Yu. A. Kotov M. G. Ivanov O. M. Samatov V. V. Lisenkov V. V. Platonov A. M. Murzakaev A. I. Medvedev E. I. Azarkevich 《Laser Physics》2006,16(1):116-125
YSZ, YSZ + Al2O3, Ce0.78 Gd0.22O2−δ, and 5NdY2O3 nanopowders are obtained using target evaporation with a repetitively pulsed CO2 laser and subsequent vapor condensation in the flow of a carrier gas. The design of the laser complex for producing the nanopowder
and the block diagram and the characteristics of the repetitively pulsed CO2 laser pumped by a combined discharge are presented. The size distribution of the nanoparticles is studied and the x-ray data
are reported. It is demonstrated that a nanopowder output rate of 15–75 g/h linearly increases with the mean laser power.
Under equal conditions, the size distribution of the particles is weakly affected by the type of the target material. The
results obtained are interpreted.
Original Text ? Astro, Ltd., 2006. 相似文献
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A combined method of excitation of a gaseous medium is used in an investigation of the energy characteristics of a non-self-sustaining
discharge as functions of the capacitance of the capacitor bank, the number of pulses per burst, and the burst repetition
rate for different time intervals between the pulses in a burst and different flow velocities of the gas. It is shown for
infrared lasers that under optimal pumping conditions the average discharge power can reach 8.5 W/cm3 for a pulse power of 25 W/cm3.
Zh. Tekh. Fiz. 68, 33–38 (May 1998) 相似文献
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