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SIBERIAN JOURNAL OF PHYSICS. Scientific Journal. 2017. V12, i 4 |
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High-Energy and Accelerator Physics, Physics of High-Temperature Plasma |
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Epshteyn L. B., Akhmetshin R. R., Grigogiev D. N., Kazanin V. F., Melnik A. S., Shoukovy Dz. V., Yudin Yu. V. Analysis in Real Time of the Electromagnetic Calorimeter Data of Experiment COMET In this paper, an algorithm for real-time analysis of the COMET experiment calorimeter is described. In order to ensure the stable operation of the detector's information reading system, it is necessary to make a decision to start basing on the information from the calorimeter. At the same time, it is required to provide energy resolution in real time no worse than 5 %. On the basis of the simulation results a signal processing algorithm for determination in real time of the energy deposited by incident particles in the calorimeter based on the digitization of signals and their analysis in programmed logic in the traveling wave mode has been developed and optimized. The proposed algorithm was tested by Monte-Carlo simulation, test-bench measurements and electron beam experiments. The results satisfy to the experimental requirements. |
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Tuev P. V., Sosedkin A. P., Lotov K. V. Formation of an Accelerated Plasma Electron Bunch in Quasistatic Simulations of Wakefield Acceleration Plasma wakefield acceleration studies currently rely considerably on simulating this effect numerically using highly specialized software. Exorbitant computational difficulty of the problem requires simplifying models and methods, limiting such software applicability. Quasistatic approximation, for example, utilizes a plasma model that does not include trapping plasma electrons with the wakefield. This article presents a method that reuses a plasma-beam solver to calculate parameters of wakefield-trapped plasma electrons. |
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Maltseva M. V., Pavlov V. M., Samoilov S. L., Andrianov A. V., Pivovarov I. L. Measurement of Resonators of the Sled Multiply Power System Power compression system consists of high quality cavities, which store electromagnetic field energy. Such system allows increasing the power of accelerating field, which is used for charged particles acceleration in the linear accelerators. The design of the power compression system and the work principle are discussed in the paper. The electromagnetic characteristics of the cavities and the envelope of the reflected power with gain factor are measured. On the basis of achieved data the analysis of work of the disk loaded accelerating structure, which is excited by produced compression system, is presented. |
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Belikov O. V., Kozak V. R., Medvedko A. S. Hardware for Increasing Reliability of the Power Supply System for Corrector Electromagnets A magnet system of modern accelerator facility requires many controlled electromagnets for correcting
a beam location. Every corrector electromagnet is fed by personal precise power supply usually. |
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Physics of a Fluid, Neutral and Ionized Gases |
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Zamuraev V. P., Kalinina A. P. Two-Mode Unilateral Surface Effect on Transonic Flow around the Symmetrical Wing Profile The effect of the forced oscillations of the surface element on one side of the airfoil on the
shock-wave structure in the transonic flow is studied numerically in the paper. The two-mode oscillations |
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Mullyadzhanov R. I., Sandberg R. D., Abdurakipov S. S., George W. K., Hanjalic K. On Helical Structures in a Round Turbulent Jet Using Direct Numerical Simulation (DNS) database we performed a statistical analysis of the characteristics of coherent structures in a turbulent circular pipe jet for Reynolds number Re = 5940 at a distance up to 40 pipe diameters from an inlet. It was shown that the optimal basic functions of the Proper Orthogonal Decomposition of velocity fields have the form of spiral perturbations and correspond to the coherent vortex structures present from the near to far field of the jet. The first two mirror-symmetric POD modes containing about 5 % of the total turbulent kinetic energy describe the spatial structure and dynamics of large-scale velocity fluctuations of the first azimuthal mode m = 1 in the mixing layer of turbulent jet. |
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Shikalov V. S., Klinkov S. V., Ryashin N. S., Kosarev V. F. Measurement of Bronze Particles Velocity in Flow From the Cold Spraying Ejector Nozzle The experimental dependence of spherical aluminum bronze microparticles Metco 51F-NS (mean particle size 44 ?m, Oerlikon Metco, USA) in flow from the axially symmetric ejector nozzle with a central body on the stagnation pressure determined by a nozzle configuration with keeping constant vacuum at the central body cutoff. It is found that the dependence has an extremum in which derivative sign changes distinguishing ejector nozzles from the typical de Laval nozzles used in cold gas-dynamic spraying. It was shown in reference experiments that the maximum values of the microparticles velocity from the experimental ejector nozzle are close to the velocity values of such particles in the flow from the Laval nozzle corresponding to the stagnation pressure values. The obtained results open wide prospects to use ejector nozzles with a central body and open-type powder feeders in cold gas-dynamic spraying. |
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Popov V. N., Shchukin V. G. Numerical Study of Thermophysical Processes of Metal Modification with High-Frequency Induction Heating of Substrate Surface Numerical modeling of thermophysical processes during the modification of the surface layer of metal in a moving substrate was carried out. The substrate surface is supposed to be covered with a layer of nanoscale particles of refractory compounds, which after penetration into the melt serve as centers of crystallization. For heating and melting of metal, continuous induction treatment by a powerful electromagnetic field is used. The distribution of electromagnetic energy in the substrate is described by empirical formulas. Based on the results of numerical experiments, the distribution of the temperature field, the dimensions of the melting and crystallization zones, the kinetics of solid phase growth, the area of the treated substrate surface, depending on the speed of its movement and the characteristics of induction heating were estimated. |
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Fomichev V. P., Yadrenkin M. A. Experimental Study of the MHD Interaction ahead the Model of the Reentry Vehicle in the Hyperzer Flow of Air The flow ahead a blunt body under the conditions of local magneto-gasdynamic interaction during the ionization of the air flow by a high-voltage pulse discharge has been studied experimentally. The possibility of controlling the shock-wave structure of a hypersonic flow is shown. The increase of the deflection of the bow shock wave from the model is demonstrated. Stuart's parameter has been estimated using the pressure measurement at the critical point of the model. |
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Solid-State and Semiconductor Physics, Physics of Nanostructures |
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Vokhmintsev A. S., Minin M. G., Weinstein I. A. Parameters of the Spectral-Resolved Thermoluminescence of Hexagonal Boron Nitride Micropowders of hexagonal Boron Nitride (h-BN) irradiated by ultraviolet light with 210 nm wavelength were studied by the means of thermally stimulated luminescence (TSL) with spectral resolution. Parameters (activation energy, effective frequency factor, kinetics order) were determined for the case of multitrap system. It was shown that TSL in 380 nm and 425 nm was caused by the escape of electrons from single- (1B) and three-boron (3B) centers with energy levels 0.7 and 1.2 eV below the bottom of the conduction band to the Carbon hole levels (CN-centers) with energy 1.4 eV above the top of the valence band. It was found that under the thermal activation of electron (1B- and 3B-centers) and hole (CN-centers) traps in the TSL mechanisms the processes of first and second order of kinetics were dominating, respectively. A tunneling mechanism for charge transfer from deep electron traps to 1B- and 3B-centers in heated h-BN samples was proposed. |
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Rodyakina E. E., Sitnikov S. V., Latyshev A. V. Electromigration Effect on Silicon (001) Surface under Homoepitaxy Conditions In situ ultrahigh vacuum reflection electron microscopy and ex situ atomic force microscopy were applied to investigate initial stages of drift induced step bunching instabilities on silicon (001) surface at 1100 °Ñ with homoepitaxial growth and sublimation. The power low time dependences of mean distance, mean terrace width between atomic step bunches were obtained. It was found powers have been different under sublimation and growth conditions and were less than 0.5 that have been previously experimentally measured for long time dependence. Our observation showed that growth rate increasing have suppressed combining steps in the bunch due to increasing of step fluctuation amplitude at initial stage of bunching. |
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Chemical, Biological and Medical Physics |
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Skovpin I. V., Zhivonitko V. V., Koptyug I. V. Some Aspects of the Observation of Parahydrogen- Induced Polarization in Hydrogenation on Immobilized Rhodium Complexes The possibility to use catalysts formed during the reduction of immobilized rhodium complexes under «mild» conditions of the hydrogenation reaction was studied in order to obtain a continuous flow of hyperpolarized propane. It was found that the resulting catalysts are more effective in the context of the production of hyperpolarized propane compared to supported metal catalysts prepared by conventional methods. |
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