Сборник рефератов статей сотрудников РФЯЦ-ВНИИЭФ, опубликованных в иностранных журналах и российских журналах, выпускаемых на английском языке в 2014 г. | |
1. | Gorbatenko M. V., Neznamov V. P.,Equivalence and hermiticity of Dirac Hamiltonians in the Kerr gravitational field // Annalen der Physik, 2014, V.526, №11-12,Pp.491-498 Russian Federal Nuclear Center VNIIEF, Sarov, Russia In the paper, for the Kerr field, we prove that Chandrasekhar's Dirac Hamiltonian and the self-adjoint Hamiltonian Hηwith a flat scalar product of the wave functions are physically equivalent. Operators of transformation of Chandrasekhar's Hamiltonian and wave functions to the η representation with a flat scalar product are defined explicitly. If the domain of the wave functions of Dirac's equation in the Kerr field is bounded by two-dimensional surfaces of revolution around the z axis, Chandrasekhar's Hamiltonian and the self-adjoint Hamiltonian in the η representation are Hermitian with equality of the scalar products, (ψ, Hψ) = (Hψ, ψ). |
2. | V. Della Corte a, S. Ivanovski b, F. Lucarelli a, A. Rotundi a, V. Zakharov c, d, M. Fulle e, A. V. Rodionov f, J. F. Crifo g, N. Altobelli h, E. Mazzotta Epifanib, Simulated measurements of 67P/Churyumov–Gerasimenko dust coma at 3 AU by the Rosetta GIADA instrument using the GIPSI tool// Astronomy and Computing, 2014, Vol. 5, Pp. 57–69 a Università Parthenope, Dip. Scienze Applicate, Naples, Italyb INAF - Osservatorio Astronomico di Capodimonte, Naples, Italyc Gordien Strato S. A. R. L., Guyancourt, Franced LESIA, Observatoire de Paris, Meudon, Francee INAF - OsservatorioAstronomico di Trieste, Trieste, Italyf Russian Federal Nuclear Center VNIIEF, Sarov, Russiag LATMOS, CNRS/UVSQ, Guyancourt, Franceh ESA-ESAC, Madrid, SpainGIADA (Grain Impact Analyzer and Dust Accumulator) is an in situ instrument, on board the Rosetta spacecraft, designed to measure the dynamical properties of the dust grains emitted by the comet 67P/Churiumov–Gerasimenko (hereafter 67P/C–G). It consists of three subsystems able to measure the mass and speed of single dust grain and dust mass flux. Once the orbit and the attitude of a spacecraft are defined, it is needed to simulate the performances of an in situ instrument. We present simulated GIADA performances to evaluate its capability in fulfilling its scientific objectives along specific orbits. In order to perform these simulations, because of the lack of real data on near-nucleus cometary environment, it is necessary to use a modeled dust coma along the spacecraft (S/C) orbits. We developed GIPSI (GIADA Performance Simulator), a simulation tool conceived to replicate the GIADA capability in detecting coma dust features through the dust abundances, mass and velocity dust distributions measurements. Using state-of-the-art coma modeling, we evaluated three different Rosetta orbit mission scenarios. We outline the optimalS/Corbit for GIADA by means of achievable dust coma evolution description, number of collected particles and grain velocity measurements. The quasi circular orbit with a 5 km peri-center radius and a 10 km apo-center radius, during the pre-landing close observation phase is the best suited for the GIADA instrument. |
3. | V. F. Kolesov, V. Kh. Khoruzhii, S. V. Vorontsov, A. A. Devyatkin, M. I. KuvshinovandV. V. Sazhnov,NeutronCharacteristics of the Two-Section BIGR + UFN-P Complex // Atomic Energy, 2014, Vol. 115, № 6, Pp.367-374 Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblast The basic design was developed for a two-section pulsed complex BIGR + UFN-P, which is supposed to be the main unit of an irradiation system with a multifunctional circuit loop for testing NPP fuel with different coolants under nonstandard conditions, and a series of calculations of the static and dynamic neutron parameters was putational studies substantiated the possibility of developing a laboratory irradiation facility with neutron fluence to 1.3·1016 cm –2 and duration ≥90 msec in a 100 cm high and 15 cm in diameter cavity with radial fluence nonuniformity factor ≤10%. |
4. | Shanenko A. K.,Possibility of using nuclear explosions to prevent the asteroid Apophis from colliding with Earth // Atomic Energy, 2014, Vol. 116, No.1, P.64-71 Russian Federal Nuclear Center VNIIEF, Sarov, Russia The possibility of using nuclear explosions to prevent dangerous space objects, specifically, the asteroid Apophis, from colliding with our planet is evaluated. Two variants are considered: delivery of an impulse capable of deflecting the trajectory to a safe distance from Earth or fragmentation by means of a powerful explosion into fragments small enough not to cause a catastrophe during an encounter with Earth. The dynamics of the destruction of the asteroid is examined. The fragment size distribution after a nuclear explosion with a definite energy release is presented. It is concluded that to prevent a dangerous collision between our planet and the asteroid Apophis the nuclear explosions must be applied well ahead of time. |
5. | Dubinov A. E., Kitayev I. N.,Exact Solutions of the Kompaneets Equation for Photon “Comptonization” Kinetics // Astrophysics, 2014, Vol. 57, No.3, pp 401-407 Russian Federal Nuclear Center VNIIEF, Sarov, Russia The nonlinear Kompaneets equation for the evolution of the spectrum of a photon gas with Compton scattering in a rarefied nonrelativistic electron plasma (i. e., the “comptonization” of the radiation) is examined. Exact solutions of this equation are obtained by separation of variables. The solutions are expressed in terms of transcendental Heun and Bessel functions. |
6. | Yu. B. Kudasov1, D. A. Maslov2, ChargeorderingofLuFe2O4electronicmultiferroic // Bulletin of the Russian Academy of Sciences: Physics, 2014, Volume 78, Issue 1, pp 21-25 1Sarov Physics and Technology Institute, National Research Nuclear University (MEPhI), Sarov, Russia 2Russian Federal Nuclear Center–VNIIEF and Sarov Institute of Physics and Technology, Sarov, Russia Charge ordering of iron ions in LuFe2O4 frustrated electronic ferroelectric with variable valence is considered. Charge degrees of freedom are described in frameworks of Ising model with Coulomb interaction between sites. Mean field approximation is used to find free energies of the most probable structures. Phase diagrams of a single triangular bilayer and a system of triangular bilayers are plotted. A partially disordered dimer structure is proposed as a 2D high temperature phase. The transition from 2D to 3D ordering associated with a drop in temperature and the formation of spontaneous dipole moments is discussed. |
7. | V. N. Piskunov, D. V. Tsaplin, R. А. Veselov,Simulation of particle ejecta effects from the surface under impulse action// Communications in Nonlinear Science and Numerical Simulation,2014,Volume 19, Issue 3, Pр. 638–648 Russian Federal Nuclear Center–VNIIEF and Sarov Institute of Physics and Technology, Sarov, Russia This paper presents research results of ejecta due to plane shock wave arrival at a free smooth surface of a homogeneous pattern in the cluster dynamics (CD) simulation. Provided are 3D simulation results illustrating that ejecta effect is not only due to the physical reasons but also due to the side computation effects. One-dimensional model is developed to study the problems of cluster motion. This model was used to analyze the cluster behavior when a shock wave arrives at the boundary of the pattern. The oscillation character of the near-boundary clusters was analyzed as well as the impact of the interaction potential anharmonicity. It is shown that the most high-frequency mode of oscillations of the cluster lattice defined by potential anharmonicity (with neighbors moving in opposite phase) plays an important role in side ejecta effects. Hence, the criteria was developed to define the threshold loading velocity associated with ejecta in 3D problems. The method is suggested to eliminate the ejecta computation effects using the modification of cluster motion equations. The efficiency of this method is verified in a number of 3D simulations. It is shown that the suggested approach eliminates the side ejecta effects and keeps the fundamental physical regularities of loading and further motion of the pattern. |
8. | Kuz'mitskiiI. V., Bel'skiiV. M., ShuikinA. N., ShutovV. V., IbragimovR. A., Pul' V. V., SviridovaI. A., StadnikA. L.,Energy release behind the Jouguet point during detonation of plasticized PETN from the results of experiments by the T-20 method// Combustion, Explosion and Shock Waves,2014,Volume 50, Issue 2, Pp. 235-241Institute of Experimental Physics, Federal Nuclear Center, Sarov, Russian Federation The trajectory of motion of a copper shell, the velocity of its flight, and the pressure of the explosion products on the inside of the copper shell were simulated. It was found that there is a significant difference in pressure behavior between experiments and calculations performed using the standard equations of state of explosives and explosion products. Most likely, there is a significant contribution of kinetic processes to the energy release behind the Jouguet point. In this case, the conversion of explosives to explosion products apparently include not only exothermic reactions but also endothermic processes. |
9. | 1 Sarov Physical-Technical Institute of National Research Nuclear University “MEPhI” 2 Institute of Physics of Explosion, Institute of Experimental Physics (VNIIEF), Federal Nuclear Center Phase transformations in VT1-0 titanium were studied. Shock profiles in the pressure range of 10-26 GPa were recorded by polyvinylidene fluoride sensors. Sound velocities in shock-compressed titanium samples were measured by two methods. At a pressure less than 30 GPa, the speed of sound in titanium was determined by the counter unloading method using Manganin gauges, and at a pressure of 30-150 GPa, it was determined by the overtaking unloading method using indicator liquids. At a pressure of 20-40 and 60-90 GPa, the pressure dependences of the speed of sound have breaks, the first of which is apparently associated with the α → ω conversion, and the second with melting. X-ray analysis revealed the presence of the ω phase in the samples in steel capsules recovered after loading at a pressure of 9-23 GPa. The dependence of the yield of the ω phase on the loading pressure has the form of a curve with a maximum at ≈15 GPa. |
10. | Medvedev A. B.1,2, On the Presence of States with a Negative Grüneisen Parameter in Overdriven Explosion Products // Combustion, Explosion and Shock, 2014, Volume 50, Issue 4, Pp.463 1 Russian Federal Nuclear Center VNIIEF, Sarov, Russia 2 Sarov Physical-Technical Institute Experimental data on the properties of explosion products in overdriven detonation for 50/50 TNT/RDX and PBX-9502 explosives indicate conditions characterized by a negative Grüneisen parameter. Given a possible relationship of this anomaly with the properties of explosion product components, available experimental data for nitrogen, carbon monoxide, carbon dioxide, and water are analyzed. The first three of these (carbon dioxide specifically) are capable of manifesting a negative Grüneisen parameter at pressures and temperatures characteristic of the anomaly of overdriven explosion products. |
11. | Medvedev A. B.ab, Wide-range multiphase equation of state for iron // Combustion, Explosion and Shock Waves, 2014, Volume 50, Issue 5, Pp. 582-598aInstitute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Russian Federation b Sarov State Physics and Technical Institute, Department of the National Research Nuclear University (Moscow Engineering Physics Institute), Sarov, Russian Federation A semi-empirical equation of state for iron with allowance for five condensed phases (α, γ, δ, ε, and liquid phases), evaporation, and thermal ionization is derived. As a whole, results of model calculations are consistent with static and dynamic experimental data in the pressure range from the atmospheric value to ≈10 TPa and in the temperature range from room temperature to ≈105K. The viscosity of liquid iron under conditions typical for the Earth core is estimated on the basis of the liquid model. |
12. | Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast A semi-empirical wide-range equation of state of compounds of lithium isotopes with hydrogen isotopes is proposed. This equation allows thermodynamic properties to be calculated both in the range of comparatively small densities, pressures, and energies available for experimental studies and in the range of superhigh densities, pressures, and energies where the states can only be estimated at the moment by calculations in accordance with theoretical models. The equation of state contains empirical functions, which allow the composition of the isotopes and the influence of the hydroxide admixture on the compound properties to be taken into account. The capabilities of the equation of state are demonstrated by an example of the description of experimental and numerical data characterizing thermodynamic and thermophysical properties of several compounds of lithium and hydrogen isotopes. |
13. | Bragunets V. A.a, Kondrokhina I. N.a, Podurets A. M.ab, Simakov V. G.a, Tereshkina I. A.ab, Tkachenko M. I.a, Trunin I. R.ab, Experimental study and mathematical modeling of spall fracture and aluminum compaction //Combustion, Explosion and Shock Waves, 2014, Volume 50, Issue 6, Pp. 720-724 a Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Russian Federation b Sarov Physico-Technical Institute, Branch of National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Sarov, Russian Federation Variants of experiments in which prefractured samples (in tests on spall fracture) are further compacted by shock reloading are considered on the example of aluminum. The results of the experimental-computational study and metallographic analysis of recovered samples in the tests are used to determine the pressure of compacting aluminum, which is ≈2 GPa. |
14. | Babich L. P., Loiko T. V., Rodigin A. V., Vavilov-Cherenkov radiation of a runaway electron subnanosecond pulse generated by discharge in the open atmosphere // Doklady Physics, 2014, Volume 59, Issue 8, Pp. 351-354Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast Results of pioneering observations of VCR pulses from high energy runaway electrons (RE) generated by an electric discharge in such a dense medium as air at atmospheric pressure are presented. The RE current pulse was detected using a collector, which was an aluminum disk 20 mm in diameter located outside the gas discharge diode at a distance of 7 mm away from the anode. The collector signal was conveyed directly to an oscilloscope input using an RF cable 8 m long. A high voltage pulse with a subnanosecond front triggers multiple over voltages on a gas discharge diode in the open atmosphere, leading to the development of a discharge, in which a subnanosecond RE pulse with an energy of hundreds of kiloelectron volts is generated. A cathode configuration consisting of a set of emitting blades made it possible to enhance the RE yield due to discharge in the open atmosphere by a factor of four or five in comparison with the yield detected experimentally with our traditional cathode configuration. |
15. | Budnikov D., Demanov V., Filchagin S., Ilkaev R., Korneev A., Kuryakin A., Mamonov A., Naumov N. P., Nazarenko S., Nazarov G., Punin V., Puchagin S., Strabykin K., Sukhorukov M., Tumkin A., Vikhlyantsev O., Vinogradov Y., Vyushin A., Zaviyalov N. et al., Neutron emission from electromagnetic dissociation of PB nuclei at √SNN= 2.76 TEV measured with the ALICE ZDC // EPJ Web of Conferences, "1st International Conference on New Frontiers in Physics, ICFP 2012" 2014. P. 00073. Russian Federal Nuclear Center VNIIEF, Sarov, Russia The ALICE Zero Degree Calorimeter system (ZDC) is composed of two identical sets of calorimeters, placed at opposite sides with respect to the interaction point, 114 meters away from it, complemented by two small forward electromagnetic calorimeters (ZEM). Each set of detectors consists of a neutron (ZN) and a proton (ZP) ZDC. They are placed at zero degrees with respect to the LHC axis and allow to detect particles emitted close to beam direction, in particular neutrons and protons emerging from hadronic heavy-ion collisions (spectator nucleons) and those emitted from electromagnetic processes. For neutrons emitted by these two processes, the ZN calorimeters have nearly 100% acceptance. During the √sNN= 2.76 TeV Pb-Pb data-taking, the ALICE Collaboration studied forward neutron emission with a dedicated trigger, requiring a minimum energy deposition in at least one of the two exploiting also the information of the two ZEM calorimeters it has been possible to separate the contributions of electromagnetic and hadronic processes and to study single neutron vs. multiple neutron emission. The measured cross sections of single and mutual electromagnetic dissociation of Pb nuclei at √sNN= 2.76 TeV, with neutron emission, are σsingle EMD= 187:4 ± 0.2 (stat.)-11.2+13.2(syst.) b and σmutual EMD= 5.7 ± 0.1 (stat.) ±0.4 (syst.) b, respectively [1]. This is the first measurement of electromagnetic dissociation of208Pb nuclei at the LHC energies, allowing a test of electromagnetic dissociation theory in a new energy regime. The experimental results are compared to the predictions from a relativistic electromagnetic dissociation model. |
16. | B. P. Kosyakov, Thepedagogicalvalueofthefour-dimensionalpicture: I. Relativisticmechanicsofpointparticles // European Journal of Physics, 2014, Volume 35, Number 2, Р.025012 Russian Federal Nuclear Center–VNIIEF, Sarov, Russia In this paper we outline two subjects of relativistic mechanics: (i) the set of allowable world lines, and (ii) the origin of the relativistic law of dynamics governing point particles. We show that: (i) allowable world lines in the classical theory of particles and fields are quite simple geometric objects as opposed to their associated three-dimensional trajectories; and (ii) Newton's second law requires neither modification nor generalization, it should only be smoothly embedded in the four-dimensional geometry of Minkowski spacetime to yield the dynamical law for relativistic particles. |
17. | Russian Federal Nuclear Center–VNIIEF Sarov, Russia A definition of the electromagnetic field can be neatly formulated by recognizing that the simplest form of the four-force is indeed feasible. We show that Maxwell's equations almost entirely stem from the properties of spacetime, notably from the fact that our world has dimensiond= 4. Their complete reconstruction requires three additional assumptions that are seemingly divorced from spacetime properties but which may, in fact, have much to do with their geometry. |
18. | Budnikov D., Filchagin S., Ilkaev R., Kuryakin A., Mamonov A., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al., Neutral pion production at midrapidity in pp and Pb–Pb collisions at √sNN TeV// European Physical Journal C, Volume 74, Issue 10, Article number 3108Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast Invariant yields of neutral pions at midrapidity in the transverse momentum range (Formula presented.)c measured in Pb–Pb collisions at (Formula presented.) TeV are presented for six centrality classes. The pp reference spectrum was measured in the range (Formula presented.)c at the same center-of-mass energy. The nuclear modification factor, (Formula presented.), shows a suppression of neutral pions in central Pb–Pb collisions by a factor of up to about (Formula presented.) for (Formula presented.) ≤ (Formula presented.)c. The presented measurements are compared with results at lower center-of-mass energies and with theoretical calculations. |
19. | BudnikovD., FilchaginS., IlkaevR., KuryakinA., MamonovA., NazarenkoS., PuninV., TumkinA., VinogradovY., VyushinA., ZaviyalovN. etal,.Event-by-event mean pT fluctuations in pp and Pb–Pb collisions at the LHC // European Physical Journal C, 2014, Volume 74, Issue 10, Article number 3377Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast Event-by-event fluctuations of the mean transverse momentum of charged particles produced in pp collisions at 0.9, 2.76 and 7 TeV, and Pb–Pb collisions at 2.76 TeV are studied as a function of the charged-particle multiplicity using the ALICE detector at the LHC. Dynamical fluctuations indicative of correlated particle emission are observed in all systems. The results in pp collisions show little dependence on collision energy. The Monte Carlo event generators PYTHIA and PHOJET are in qualitative agreement with the data. Peripheral Pb–Pb data exhibit a similar multiplicity dependence as that observed in pp. In central Pb–Pb, the results deviate from this trend, featuring a significant reduction of the fluctuation strength. The results in Pb–Pb are in qualitative agreement with previous measurements in Au–Au at lower collision energies and with expectations from models that incorporate collective phenomena. |
20. | MokrushinV. V., TsarevM. V., KorshunovK. V., PostnikovA. Yu., TsarevaI. A., Resistometryandimpedancespectroscopyforcharacterization of powders used in SHS reactions Russian Federal Nuclear Center–VNIIEF and Sarov Institute of Physics and Technology, Sarov, Russia Presented are some examples of successful application of dc resistometry and impedance spectroscopy to characterization of micro and nano powders commonly used in SHS technology. |
21. | KantsyrevA. V.a a Institute for Theoretical and Experimental Physics (ITEP), Moscow Russian Federation b Facility for Antiproton and Ion Research (FAIR) in Europe GmbH, Darmstadt, Germany c Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Russian Federation d Center for Elaboration and Commercialization of New Technologies, Moscow, Russian Federation e Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblast, Russian Federation f GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany A proton radiography facility with the use of magnetic optics (PUMA proton microscope) has been developed at the TWAC-ITEP accelerator-accumulator facility (the ITEP terawatt accumulator) for measuring the substance density distribution inside static and dynamic objects using the proton beam with an energy of 800 MeV. The proton radiographic image of an object of investigation placed in the object plane of the setup is formed in the plane of the detector with magnification K = 4 with the aid of the magneto-optical system consisting of four quadrupole lenses on permanent magnets. The PUMA facility is intended for measuring objects with an areal density of up to 20 g/cm2with a field of vision as large as 20 mm in diameter. The spatial resolution of radiographic images depends strongly on the areal density of the object of investigation. For the PUMA facility, the spatial resolution varies from 60 to 115 μm at an areal density of 0.46-17 g/cm2, respectively. The dynamical state of substance can be investigated in four consecutive radiographic images, since the time structure of the proton beam consists of four pulses, each with a duration of 47 ns (full width at half maximum (FWHM)) and an interval of 250 ns between them. This article is devoted to the description of the proton microscope construction. The main metrological characteristics of the facility are described using experiments with static and dynamic objects as an example. |
22. | MaslovV. V., RumyantsevV. G., BasmanovV. F., BudnikovD. V., GarinA. V., DrozdovI. Yu., ErshovD. A., KorkinD. S., MakeevN. G., MolodtsevD. A., MoskvinN. I., NazarenkoS. T., PetrushinO. N., FalinA. P., YukhnevichV. A., AKPU-200 movablecapacitorinstallation// Russian Federal Nuclear Center All-Russian Research Institute of Experimental Physics, Sarov, Nizhny Novgorod Oblast, Russian FederationA movable electrophysical capacitor installation with a 250-kJ maximum bank energy, which generates intense neutron pulses, is described. A current pulse generator with a capacitive energy storage forms the basis of the installation. When the initial voltage at the capacitor bank is up to 35 kV, the installation ensures a flow of current pulses with amplitudes of up to 2 MA in a gas-discharge plasma-focus chamber, which is filled with an equal-component deuterium-tritium (DT) mixture. Under these conditions, the chamber is capable of repeatedly generating single fast-neutron pulses with an energy of 14.1 MeV, a duration of -70 ns, and an integral yield over 1013 neutrons/pulse. |
23. | Kornienko D. S., Kravchenko A. G., Litvin D. N., Mis'Ko V. V., Rukavishnikov A. N., Senik A. V., Starodubtsev K. V., Tarakanov V. M., Chaunin A. E., Streak cameras for laser fusion experiments // Instruments and Experimental Techniques, 2014,Т. 57. № 2.Рр. 165-175. Russian Federal Nuclear Center All-Russian Research Institute of Experimental Physics, Sarov, Nizhny Novgorod Oblast, Russian Federation Results of the streak camera development for the new laser facility UFL-2M are presented. This streak camera can be used for diagnosing laser beams and plasma parameters. Its main characteristics are as follows: the maximum temporal resolution is ≤5 ps, the spatial resolution is ≥20 line pairs/mm, and the dynamic range is ≥1000. |
24. | Kravchenko A. G., Litvin D. N., Mis'Ko V. V., Senik A. V., Starodubtsev K. V., Tarakanov V. M., Investigation of the optical characteristics of laser plasma by photochronography methods// Instruments and Experimental Techniques, 2014, Т. 57. № 2. Рр. 176-182. Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblast An investigation is made of the dynamics and visible-range luminosity of the plasma cloud produced behind the front of a shock wave in air at a pressure of 1 Torr. The shock wave was produced on introducing the radiation of the twelve-channel Iskra-5 laser facility with a total energy of ~2300 J into a hollow spherical plastic target of mass ~10-4 g. Experimental data are compared with simulations. |
25. | Repin P. B., Markevtsev I. M., Kornilov S. Yu., A fast time-response bolometer for soft X-ray radiation energy measurements in a high-current Z-pinch // Instruments and Experimental Techniques, 2014,Т. 57. № 2. Рр. 183-188. Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblast Ahigh-sensitivitybolometerwithashorttimeresponseto heating with externalradiationhas been developed. It is intendedformeasuring the integral parameters ofsoftX-rayradiationof liner plasma. Thebolometeris adapted to the conditions of explosion experiments with an increased level of electromagnetic pickups at facilities that are based on magnetic-explosion generators with megaampere currents. Thebolometerhasametal casingforimproving the noise immunity ofmeasurements. A2-?m-thick nickel foil is used as the materialforthe resistive element of the working substance of thebolometer. The choice of the material and the geometrical dimensions of thebolometerworking elements were analyzed. The ultimate thermal load on thebolometerwas determined. Atechniqueforcalibrating the working elements usingapulse current was developed. The working capacity, good noise immunity, andahigh sensitivity of thebolometerwere demonstratedinexperiments. The dynamic rangeinmeasurementsof the surfaceenergydensity ofXraysis 0.03-0.3 J/cm2. |
26. | Dushina L. A., Kornienko D. S., Kravchenko A. G., Litvin D. N., Mis'Ko V. V., Rukavishnikov A. N., Senik A. V., Starodubtsev K. V., Tarakanov V. M., Chaunin A. E., A technique for studying the spectral composition and duration of radiation accompanying a shock wave at the rear surface of materials under direct laser irradiation // Instruments and Experimental Techniques, 2014, Т. 57. № 2. Рр. 189-194 Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblast A photochronographic technique for studying the spectral composition and duration of radiation that accompanies the appearance of a shock wave on the rear surface of a loaded target has been developed. The spectral resolution of this technique was evaluated. A method of the through calibration of the recording channel using radiation of a source with the known spectrum was proposed. The results of the performed calibration are used to restore the spectral distribution on the basis of the obtained spectrochronograms. |
27. | Aleksandrov D. V.a, Vinogradov A. A.a, Ippolitov M. S.a, Lebedev V. A.a, Manko V. I.a, Nikulin S. A.a, Nyanin A. S.a, Sibiriak Yu. G.a, Akindinov A. V.b, Vodopyanov A. S.c, Gorbunov N. V.c, Zaporozhets S. A.c, Nomokonov P. V.c, Rufanov I. A.c, Budnikov D. V.d, Vinogradov Yu. I.d, Demanov V. A.d, Zavyalov N. V.d, Kuryakin A. V.d, Mamonov A. V.d, Nazarenko S. T.d, Punin V. T.d, Puchagin S. Yu. d, Strabykin K. V.d, Tumkin A. D.d, Filchagin S. V.d, Improving the timing resolution of an electromagnetic calorimeter based on lead tungstate crystals // Instruments and Experimental Techniques, 2014, Volume 57, Issue 3, Рр. 233-247a National Research Centre Kurchatov Institute, Moscow, Russian Federation b Alikhanov Institute for Theoretical and Experimental Physics, Moscow, Russian Federation c Joint Institute for Nuclear Research (JINR), Dubna, Moscow Oblast, Russian Federation d All-Russian Research Institute of Experimental Physics (ARRIEP), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod Oblast, Russian Federation Results of the beam tests of the prototype photon spectrometer PHOS for the ALICE experiment at the Large Hadron Collider (CERN) are presented. The spectrometer is based on detector elements composed of lead tungstate (PbWO4) crystals with dimensions of 22 × 22 × 180 mm and Hamamatsu S8664-55 (S8148) avalanche photodiodes. The beam tests have been performed on the secondary T10 beamline of the PS proton synchrotron. The main emphasis has been placed on the possibility of improving the PHOS timing resolution. Introduction of an additional timing channel with a silicon photomultiplier (SiPM) used as a photodetector is shown to improve the timing resolution for 1-GeV deposited energy from current value σt= 3 to 0.3 ns. Silicon photomultipliers of the Hamamatsu MPPC S10362-33 family with an active area of 3 × 3 mm2are used in these measurements. Using fast photomultiplier tubes with an 8-mm-diameter photocathode, the timing resolution attainable in electromagnetic shower development in a lead tungstate crystal has been measured for a large-area photodetector. The timing resolution for a deposited energy of 1 GeV is 150 ps. The effect of the detector channel temperature on the timing resolution is investigated. Cooling the crystal results in an increase both in the scintillation intensity and in the decay time of the scintillator and fails to substantially improve the timing resolution. |
28. | Babich L. P., Loiko T. V., Rodigin A. V., Calibration of detectors of ionizing emissions by means of a subnanosecond runaway electron beam generated by discharge in open atmosphere at high overvoltages// Instruments and Experimental Techniques, 2014, Volume 57, Issue 3,Рр.248-254 Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblastThe electric discharge in air at atmospheric pressure under the conditions of multiple overvoltages generates an electron beam of subnanosecond means of measurements of the resolution time of registration lines including different detectors of ionizing emissions, efficiency is demonstrated of the beam application for calibration of the detectors with the subnanosecond resolution. The basic advantages of such a way of calibration is the absence of the evacuated accelerating tube, small dimensions of the source, and the big resource. |
29. | Piskunov V. N., Tsaplin D. V., Scavenging trace gases from an arbitrary dynamical source in the below-cloud layer of the atmosphere // Izvestiya - Atmospheric and Ocean Physics,2014,Volume 50, Issue 4, Pages 377-384Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast We consider the scavenging of trace gases in the below-cloud layer with their evaporation from droplets and atmospheric turbulent diffusion. This problem is solved by the method of splitting into physical processes where the dynamics of scavenging of trace gases is treated separately on the background of atmospheric diffusion and transport. These processes produce a dynamical background source of trace gases. We obtain a general solution of kinetic equations of scavenging for a source with an arbitrary background distribution. This solution is analyzed for two limiting cases: slow and fast time-varying sources (compared to the process of scavenging). The results of illustrative calculations are presented and practical recommendations are given on the calculation of the scavenging rate for numerical systems. |
30. | Budnikov D., Filchagin S., Ilkaev R., Kuryakin A., Mamonov A., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al., Measurement of visible cross sections in proton-lead collisions at √sNN= 5.02 TeV in van der Meer scans with the ALICE detector // Journal of Instrumentation,2014,Volume 9, Issue 11, Article number P11003Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast In 2013, the Large Hadron Collider provided proton-lead and lead-proton collisions at the center-of-mass energy per nucleon pair sNN=5.02 TeV. Van der Meer scans were performed for both configurations of colliding beams, and the cross section was measured for two reference processes, based on particle detection by the T0 and V0 detectors, with pseudo-rapidity coverage 4.6 < η < 4.9, -3.3 < η < -3.0 and 2.8 < η < 5.1, -3.7 < η < -1.7, respectively. Given the asymmetric detector acceptance, the cross section was measured separately for the two configurations. The measured visible cross sections are used to calculate the integrated luminosity of the proton-lead and lead-proton data samples, and to indirectly measure the cross section for a third, configuration-independent, reference process, based on neutron detection by the Zero Degree Calorimeters. |
31. | Babich L. P.,Loiko, T.V.,Rodigin, A. V.,The First Observations of Cherenkov's Radiation of Runaway Electrons Produced by Discharge in Dense Gas Plasma Science, IEEE Transactions on Plasma Science, 2014, Vol.42, Issue 4, Pp. Russian Federal Nuclear Center – VNIIEF, Sarov, Russia For the first time, Cherenkov's radiation (CR) was detected of runaway electron (RE) pulse generated by electric discharge in open atmosphere. The measured duration of the CR pulse is Δt₀.₅≈0.4 ns, the intrinsic duration does not exceed the measured duration of the pumping RE pulse Δt₀.₅≈0.15 ns. The observations of CR, executed with Plexiglas radiator, testify that the RE spectrum is stretched above the CR threshold in Plexiglas 176.4 keV. |
32. | Dubinov A. E.; Kozhayeva J. P., Generation of Nanosecond Spark Microdischarges Along the Surface of Wings of Flying Insects // IEEE Transactions on Plasma Science, 2014, Vol.42, Issue 8 Pp. 2049 – 2053Russian Federal Nuclear Center VNIIEF, Sarov, Russia A device generating spark nanosecond discharges is presented, and the effects produced by the same, which were observable on the surface of wings of flying insects, such as flies, bees, mosquitoes, and butterflies are reported for the first time. It is shown that the series of discharges having <;0.5-mJ energy per each pulse in a sequence of 0.2 Hz produces damages on the wing surface, varying from rupture of the upper wing layer or rolling of the same in case of a fly or a mosquito, to exfoliation of the wing by the shock wave produced by the discharge in case of a butterfly. |
33. | A. E. Dubinov, A. N. Maksimov, V. D. Selemir, Influence of Dipole Magnetic Field on Circular Striations Russian Federal Nuclear Center VNIIEF, Sarov, Russia A small permanent magnet has been located into a disk chamber of dc-glowing discharge with radial current. Influence of the dipole magnetic field on circular striations has been investigated. Deformation of the striation pattern is observed due to the fact that the magnet is a conductor (a metal cylinder). Illumination in a small area around the magnet is less pronounced because the plasma is displaced from the area of high magnetic field. |
34. | Dubinov, A. E. 1,Shatalova, V. V. 2,Voids of Brightness in Nanosecond Sliding Microdischarges in Narrow Slot // IEEE Transactions of Plasma Science, 2014, Vol. 42, Issue 10, Pp.2644-2645 1 Russian Federal Nuclear Center VNIIEF, Sarov, Russia 2 Sarov Physical-Technical Institute, Sarov, Russia This paper describes the research work studying a nanosecond microdischarge sliding on a dielectric surface and propagating in a narrow slot in the air of atmospheric pressure. Images of a discharge channel with high spatial resolution were obtained using a digital microscope. It was found out that a plasma luminescence in the discharge could be heterogeneous along the channel length and contain dark voids and continuity breaks. |
35. | Dubinov A. E., Pylayev N. A., Sadovoy S. A., Sadchikov E. A.,HD-ImageofNanosecondMicrospark // IEEE Transactions on Plasma Science, 2014, Vol.42, Issue 10, Pp.2648-2649 Russian Federal Nuclear Center VNIIEF, Sarov, Russia. Using a digital microscope, we obtained an image with high spatial resolution of high-current nanosecond spark of submillimeter size. The spark has been formed in the air of atmospheric pressure. The diameter of the spark is ∼20 μm. |
36. | Sudarchikov V. A.1, Kaloshkin S. D.1, Cherdyntsev V. V.1, Danilov V. D.2, Dorofeev A. A.3,Bronze powder filled composite materials based on ultra-high molecular polyethylene, produced by combined mechanical activation in planetary-type mill // Inorganic Materials: Applied Research. 2014. Т. 5. № 1. P. 75-81. 1 Национальный исследовательский технологический университет «МИСиС», г. Москва 2Институт Машиноведения им. Благонравова РАН, г. Москва 3 Russian Federal Nuclear Center – VNIIEF, Sarov, Russia The structure and the thermophysical, mechanical, and tribological characteristics of bronzepowder-filled composite materials based on ultra-high-molecular-weight polyethylene were studied. The composites were prepared by combined mechanical activation followed by compaction. Microscopic investigation showed that the flaky structure formed upon mechanical activation is inherited in bulk specimens where the bronze particles are oriented predominantly in the direction perpendicular to the direction of the pressure applied in ch an arrangement of the filler particles in the matrix has a considerable effect on both the thermophysical and mechanical properties of the composite. The concentration dependences of the strength characteristics of the composites upon stretching have the form of a curve with the peak at a filler content of 1–2 vol %. The magnitude of the modulus of elasticity increases steadily with increasing content of the filler. Analysis of the tribological behavior of the composites showed that the composites with a filler content of about 10 vol % exhibit the best antifriction properties. |
37. | R. Barabanov, D. Dyanov, K. Tsiberev, V. Spiridonov, The Code LOGOS for Numerical Analysis of Nonlinear Quasi-Static Strength Problems //2014 International Conference on Computational Science and Computational Intelligence, Pp.264-266 Russian Federal Nuclear Center VNIIEF, Sarov, Russia The paper presents the finite element code LOGOS for high performance computing developed in Russian Federal Nuclear Center VNIIEF. Among other, its functionality intended to numerical analysis of quasi-static strength problems. The description of main procedures and algorithms that allow accounting both physical and geometrical non-linear effects and contact interaction, is given. At present, the code is tested and verified by a number of Russian key industrial enterprises. Results of numerical modeling of complex engineering constructions are shown that demonstrate robustness and applicability of code LOGOS to nonlinear analysis of models subjected to quasi-static loading. |
38. | K. Tsiberev, V. Spiridonov, D. Dyanov, S. Kukanov, The Finite Element Code LEGAK-DK and Its Application to Numerical Analysis of Impact and Thermal Resistances of Air Transport Package in Hypothetical Accident Conditions // 2014 International Conference on Computational Science and Computational Intelligence, Pp.267-270 Russian Federal Nuclear Center VNIIEF, Sarov, Russia The paper presents the new finite element code LEGAK-DK for high performance computational developed in Russian Federal Nuclear Center VNIIEF and some numerical simulations results of the dynamic deformations of the air transport package, subjected to impacts at a high speed. Obtained residual deformed shapes are used to perform numerical analysis of the package's thermal condition in fire. These simulations allow estimating on how a thermal resistance of the package can be reduced after high speed parison of the results with the experimental data shows that they are in a good agreement. |
39. № | A. Rodionov, V. Spiridonov, K. Tsiberev, I. Tagirova,The Code for Solving Aerodynamic Problems Based on Explicit Godunov-Kolgan-Rodionov Scheme//2014 International Conference on Computational Science and Computational Intelligence, Pp.285-287 Russian Federal Nuclear Center VNIIEF, Sarov, Russia This paper describes the finite volume code for aerodynamic problems computer modeling. The base of the technique is explicit difference Godunov-Kolgan-Rodionov scheme. Development and testing results of calculation algorithms for 2D planar flows are described. Solutions of different problems are given and the efficiency of the developed technique is being analyzed in comparison with other known codes. |
40. | Trenkin A. A., Karelin V. I., Fedoseev I. G.,Formation of Micro-channels and Generation of High-energy Electrons in Nanosecond High-voltage Discharges in Air Developing // High Voltage Engineering, 2014, V.40, №7, Pp.2211-2216 Russian Federal Nuclear Center VNIIEF, Sarov, Russia The investigations results of the different types of high-voltage nanosecond atmospheric discharges (diffusive in the gaps "wire(cathode)-plane", "rod(cathode)-plane", spark "point-plane" and in homogeneous gaps "plane-plane", as well as streamerless discharges in homogeneous gaps "plane-plane") are present. It was found out that the current channels prints, left on the electrodes surface, has the microstructure. The microstructure is a cluster (up to 1 000) of the microchannels of 1~30 µm diameters almost evenly distributed on the channels section. It was found out that in some cases the discharges develop in the regime of microstructuring of the current channels, are accompanied by generation of high-energy electrons and x-ray radiation. In this case the generation of high-energy component is stipulated by the electrons runaway in the microchannels. The calculation results of the electric field in clusters of parallel microchannels in the frameworks of the model of a bundle of parallel long cylindrical conductors are present. It is shown that in the clusters with many microchannels in the result of mutual attenuation of their fields maximum strength of the radial field could be lower than the critical one, which is necessary for ionization multiplication and expansion. This provides long existence of microchannels groups of microns radii in the high-voltage nanosecond discharges. A physical model of the streamerless discharge microstructure formation at the result of instability development of the ionization process in the avalanche stage is developed. It was established that the instability has long wave character and leads to formation of self-similar spatial structure. It is shown that the microstructure of the streamer discharges could be explained in the frameworks of this model. Three-dimensional numerical simulation of dynamics of microchannels system of high-voltage nanosecond discharges in the air of atmospheric pressure is performed in hydrodynamic approximation. It is established that fast (≈10 ns) expansion and significant decreasing of the gas concentration in the microchannels takes place at the expense of ohmic heating of the microchannels. It is shown that the microchannels expansion provides increase of electric field and gas concentration ratio up to the values that are sufficient for high-energy electrons beams and bremsstrahlung generation in them. |
41. | BobrovaA. A., DubinovA. E., EsinM. I., MaksimovA. N., SelemirV. D.,Featuresofglowdischargeignition in a gap partially filled with dielectric beads// High Temperature, 2014,Volume 52, Issue 4, Pp. 603-605Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast The article examines the features of glow discharge ignition in a gap partially filled with dielectric beads. The lower electrode was always the cathode and the upper one was the anode. The anode had a pump down hole. The electrodes were connected to the power supply with a constant power and regulated voltage and current. During the breakdown, movement of the electrons between the beads in the gas causes the occurrence of the avalanche. The avalanche development in gap I takes place in a less efficient field than the same in the absence of the beads; thus, the avalanche might come to an end at the surface of the bead located on its path. The package of the beads in the layers was irregular. After sealing and pumping down to a pressure of several Torr, the stationary DC discharge was ignited in the chamber. |
42. | S. A. Bel'kov1,V. N. Derkach1,S. G. Garanin1,E. I. Mitrofanov1,I. N. Voronich1,V. E. Fortov2,P. R. Levashov2, D. V. Minakov2, Isentropic expansion of copper plasma in Mbar pressure range at “Luch” laser facility //Journal of Applied Physics, 2014, 115, P.033506 1 Russian Federal Nuclear Center – VNIIEF, Sarov, Russia 2 Joint Institute for High Temperatures, Moscow, Russia and Moscow Institute of Physics and Technology (State University), Dolgoprudny, Russia We present experimental results on thermodynamic properties of densecopperplasmain Mbarpressurerange. The laser facility “Luch” with laser intensity 1014 W/cm2is used to compresscopperup to ∼8 Mbar by a strongshock wave;subsequentexpansionofcopperplasmainto Al, Ti, Sn allows us to obtain release isentropes ofcopperby the impedance–matching method. A theoretical analysis and quantum simulations show that in our experiments strongly coupled quantumplasmais generated. |
43. | Kaul A. M. 1, Ivanovsky A. V. 2, Atchison W. L. 1, Petrukhin A. A. 2, Duday P. V.2, Griego J. R. 1, M. Salazar1, Nadezhin S. S. 2, Tyupanova O. A. 2, Oro D. M. 1, Holtkamp D. B. 1, G. Rodriguez,1 Tabaka L. J. 1, Kraev A. I. 2, Skobelev A. N. 2, Westley D. T. 1, Anderson B. G. 1, Ivanov V. A. 2, Glybin A. M. 2, Kuzyaev A. I. 2, Stone J. B. 1, Payton J. R. 1, Goodwin P. M. 1, Q. McCulloch,1 Montoya R. R. 1, Dudin V. I. 2, Zimenkov A. A. 2, Randolph R. B. 1, F. Fierro1, Reinovsky R. E. 1, Rousculp C. L. 1, Balandina A. N. 2, Podurets A. M. 2, Damage growth and recollection in aluminum under axisymmetric convergence using a helical flux compression generator // Journal of Applied Physics, 2014, 115, P.023516 1 Los Alamos National Laboratory, P. O. Box 1663, Los Alamos, New Mexico 87545, USA 2 Russian Federal Nuclear Center, Sarov, Nizhniy Novgorod region, Russia Damage initiation and evolution, failure, and recollection processes under axisymmetric convergence were studied in the Russian-Damage experimental series, a joint effort between the Los Alamos National Laboratory and the All-Russian Institute of Experimental Physics. A helical explosive magnetic generator was used to drive a cylindrical liner shell to produce shock wave loading of a concentric cylindrical target shell. Shock wave amplitude was controlled by the liner-to-target spacing and by the magnetic field amplitude. Variation of the current pulse duration produced either a single impact, to study damage initiation through failure, or a double impact, to study failure with recollection. Both full and partial recollection of the main crack was fielding high-precision diagnostics to measure the dynamic drive conditions and material response and by employing post-shot metallographic analysis, this project produced well-characterized experimental data across a range of damage and recollection levels for the chosen material, aluminum. We present selected experimental results to illustrate the methodology and utility of this experimental technique |
44. | BabichL. P.,Fundamentalprocessescapableofaccountingfortheneutronfluxenhancementsinathunderstorm atmosphere // Journal of Experimental and Theoretical Physics, 2014, Volume 118, Issue 3, Pр. 375-383. Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblast Elementary processes capable of producing neutrons in a thunderstorm atmosphere are analyzed. The efficiency of nuclear fusion2H(2H, n)3He, photonuclear reactions (γ, Xn), electrodisintegration reactionsmnA(e-,n)mn-1, and reactions e-(p+, n)νeopposite to the β-decay is evaluated. It is shown that an unrealistically strong electric field is required for the nuclear fusion to be responsible for the neutron production in the lightning channel. The generation of neutrons in a thunderstorm atmosphere is connected with photonuclear (γ, Xn) and, at a much lower degree, electrodisintegration reactions, the relativistic runaway electron avalanches being primary parent processes. |
45. | MikhailovA. L., OgorodnikovV. A., Sasik V. S., Raevskii V. A., Lebedev A. I., Zotov D. E., Erunov S. V., Syrunin M. A., Sadunov V. D., Nevmerzhitskii N. V., Lobastov S. A., Burtsev V. V., Mishanov A. V., Kulakov E. V., Satarova A. V., Georgievskaya A. B., Knyazev V. N., Kleshchevnikov O. A., Antipov M. V., Glushikhin V. V., Yurtov I. V., Utenkov A. A., Sen'Kovskii E. D., Abakumov S. A., Presnyakov D. V., Kalashnik I. A., Panov K. N., Arinin V. A., Tkachenko B. I., Filyaev V. N., Chapaev A. V., Andramanov A. V., Lebedeva M. O., Igonin V. V.,Experimental-calculation simulation of the ejection of particles from a shock-loaded surface// Journal of Experimental and Theoretical Physics, Volume 118, Issue 5, May 2014, Pages 785-797Institute of Experimental Physics, Federal Nuclear Center, Sarov, Russian Federation The possibilities of measuring complex Pylenie, which is intended for studying the parameters of the particles ejected from the free surface of a shock-loaded material and was created at the Institute of Experimental Gas Dynamics and Detonation Physics RFNC-VNIIEF, are demonstrated. The operation of the complex is based on the following three methods, which are based on different physical principles and supplement each other: laser-optical method (macro - and microfilming), pulsed X-ray method, and piezoelectric pressure sensors. This complex is used to study the ejection of particles from the free surface of lead samples when a shock wave with a pressure of 7, 16, and 23 GPa at its front reaches this surface. The effect of the surface roughness and the pressure amplitude at the shock wave front on the quantitative characteristics of the process is shown. The calculation-theoretical simulation is performed by two-dimensional numerical calculations of gasdynamic flows, and the calculation results are used to estimate the "ejecta" characteristics in terms of the developed phenomenological model of the process. |
46. | Mochalov M. A.a, Il’kaev R. I.a, Fortov V. E.b, Mikhailov A. L.a, Raevskii V. A.a, Ogorodnikov V. A.a, Yukhimchuk A. A.a, Davydov A. I.a, Anashkin N. N.a, Arinin V. A.a, Blikov A. O.a, Baurin A. Yu. a, Davydov N. B.a, Komrakov V. A.a, Logvinov A. I.a, Manachkin S. F.a, Ryzhkov A. V.a, Tkachenko B. I.a, Fedorov A. V.a, Finyushin S. A.a, Kalashnikov D. A.a, Chudakov E. A.a, Pronin E. A.a, Bakulina E. A.a,Quasi-isentropic compressibility of deuterium and helium at pressures of 1500-5000 GPa // Journal of Experimental and Theoretical Physics, 2014, Volume 119, Issue 1, pp. 146-161 aRussian Federal Nuclear Center VNIIEF, Sarov, Russia b Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow The quasi-isentropic compressibilities of deuterium and helium plasmas are measured in the pressure range 1500-5000 GPa at densities up to 8 g/cm3using spherical experimental devices and an X-ray complex consisting of three betatrons and a multichannel optoelectronic system for taking X-ray images. The experimental results demonstrate the possibilities of high-energy-density experimental physics to reproduce the extreme states of substance typical of the Universe under laboratory conditions using the energy of traditional condensed explosives. |
47. | Astashkin M. V.a, Baranov V. K.a, Georgievskaya A. B.a, Golubinskii A. G.a, Irinichev D. A.a, Meshkov E. E.b, Stepushkin S. N.a, Syundyukov A. Y.a, Khatunkin V. Y.a, Instability of the free boundary of a water layer accelerated by a Taylor wave // JETP Letters, 2014, Volume 99, Issue 3, Pp. 146-148a Russian Federal Nuclear Center VNIIEF, Sarov, Nizhni Novgorod region, Russian Federation b Sarov Physical Technical Institute, National Research Nuclear University MEPhI, Sarov, Nizhni Novgorod region, Russian Federation The instability of the free boundary of a thin (1 mm) water layer under the action of a Taylor wave (80 MPa), which is created by a laser pulse, has been experimentally studied. The experimental results demonstrate the capabilities of the laser Doppler method for the continuous recording of a flying object (PDV method) [O. T. Strand, D. R. Goosman, and C. Martinez, Rev. Sci. Instrum. 77, 0831] for studying this problem. |
48. | Babich L. P., Bochkov E. I., Kutsyk I. M.,Mechanism of generation of runaway electrons in a lightning leader// JETP Letters, 2014, Volume 99, Issue 7, Pp. 386-390 Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast A mechanism is analyzed of the electric field enhancement in a lightning leader up to the level permitting runaway of low-energy electrons. The ionization wave propagation in the preionized domain in front of the leader makes it possible to overcome the limitation imposed on the field intensity by transversal expansion of the leader means of numerical simulations, it is demonstrated that, at the final stage of formation of a new leader step, generation of an electric field is possible in the channels of the streamer zone ahead of the new step with intensity sufficient for electron runaway and, consequently, for producing the X-ray and γ-ray pulses observed in correlation with the lightning leader steps. |
49. | Budnikov D., Filchagin S., Ilkaev R., Kuryakin A., Mamonov A., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al., Upgrade of the ALICE experiment: Letter of intent // Journal of Physics G: Nuclear and Particle Physics,2014, Volume 41, Issue 8, , Article number 087001 Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast ALICE (A Large Ion Collider Experiment) is studying the physics of strongly interacting matter, and in particular the properties of the Quark-Gluon Plasma (QGP), using proton-proton, proton-nucleus and nucleus-nucleus collisions at the CERN LHC (Large Hadron Collider). The ALICE Collaboration is preparing a major upgrade of the experimental apparatus, planned for installation in the second long LHC shutdown in the years 2018-2019. These plans are presented in the ALICE Upgrade Letter of Intent, submitted to the LHCC (LHC experiments Committee) in September 2012. In order to fully exploit the physics reach of the LHC in this field, high-precision measurements of the heavy-flavour production, quarkonia, direct real and virtual photons, and jets are necessary. This will be achieved by an increase of the LHC Pb-Pb instant luminosity up to 6×1027cm-2s-1and running the ALICE detector with the continuous readout at the 50 kHz event rate. The physics performance accessible with the upgraded detector, together with the main detector modifications, are presented. |
50. | BudnikovD., FilchaginS., IlkaevR., KuryakinA., MamonovA., NazarenkoS., PuninV., TumkinA., Vinogradov Y., Vyushin A., Zaviyalov N. et al., Technical design report for the upgrade of the ALICE inner tracking system // Journal of Physics G: Nuclear and Particle Physics,2014, Volume 41, Issue 8, Article number 087002Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast ALICE (A Large Ion Collider Experiment) is studying the physics of strongly interacting matter, and in particular the properties of the Quark-Gluon Plasma (QGP), using proton-proton, proton-nucleus and nucleus-nucleus collisions at the CERN LHC (Large Hadron Collider). The ALICE Collaboration is preparing a major upgrade of the experimental apparatus, planned for installation in the second long LHC shutdown in the years 2018-2019. A key element of the ALICE upgrade is the construction of a new, ultra-light, high-resolution Inner Tracking System (ITS) based on monolithic CMOS pixel detectors. The primary focus of the ITS upgrade is on improving the performance for detection of heavy-flavour hadrons, and of thermal photons and low-mass di-electrons emitted by the QGP. With respect to the current detector, the new Inner Tracking System will significantly enhance the determination of the distance of closest approach to the primary vertex, the tracking efficiency at low transverse momenta, and the read-out rate capabilities. This will be obtained by seven concentric detector layers based on a 50 μm thick CMOS pixel sensor with a pixel pitch of about 30×30 μm2. This document, submitted to the LHCC (LHC experiments Committee) in September 2013, presents the design goals, a summary of the R&D activities, with focus on the technical implementation of the main detector components, and the projected detector and physics performance. |
51. | Kozlov E. A.a, Ol'Khov O. V.b, Shuvalova E. V.b, Numerical 3d-modeling of spall and shear fractures in shells of austenitic 12KH18N10T steel and 30KHGSA steel under their spherical and quasi-spherical explosive loading // Journal of Physics: Conference Series, 2014, Т. 490, № 1, Pp. 012192. a Russian Federal Nuclear Center, Zababakhin Research Institute of Technical Physics, Snezhinsk, Russian Federation b Russian Federal Nuclear Center, Research Institute of Experimental Physics, Sarov, Russian Federation To pursue VNIIEF-VNIITF joint investigations, this paper briefly describes the experimental setup and provides numerical 3D-computation results (LEGAK-3D technique) on special features in the convergence dynamics of steel shells under their quasi-spherical explosive loading in the system with the 40-mm outer radius of the explosive layer. The computation results were compared with the data experimentally registered for shells of the high-purity and technical-purity unalloyed iron, the 30KhGSA steel, both as-received and quenched to HRC 35...40, and the austenitic 12Kh18N10T stainless steel. The comparison was also made with laser-interferometry results obtained directly under explosive loading, as well as with gamma-tomography and scanning electron microscopy investigations of the recovered shells. |
52. | Budnikov, D., Filchagin, S., Ilkaev, R., Kuryakin, A., Mamonov, A., Nazarenko, S., Punin, V., Tumkin, A., Vinogradov, Y., Vyushin, A., Zaviyalov, N. et al.,Measurement of charged jet suppression in Pb-Pb collisions at √SNN = 2.76 TeV, Journal of High Energy Physics, 2014, Т. 2014, № 3, Р. 013. Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblast A measurement of the transverse momentum spectra of jets in Pb-Pb collisions at √sNN= 2.76TeV is reported. Jets are reconstructed from charged particles using the anti-kT jet algorithm with jet resolution parameters R of 0.2 and 0.3 in pseudo-rapidity |η| < 0.5. The transverse momentum pTof charged particles is measured down to 0.15 GeV/c which gives access to the low pTfragments of the jet. Jets found in heavy-ion collisions are corrected event-by-event for average background density and on an inclusive basis (via unfolding) for residual background fluctuations and detector effects. A strong suppression of jet production in central events with respect to peripheral events is observed. The suppression is found to be similar to the suppression of charged hadrons, which suggests that substantial energy is radiated at angles larger than the jet resolution parameter R = 0.3 considered in the analysis. The fragmentation bias introduced by selecting jets with a high pTleading particle, which rejects jets with a soft fragmentation pattern, has a similar effect on the jet yield for central and peripheral events. The ratio of jet spectra with R = 0.2 and R = 0.3 is found to be similar in Pb-Pb and simulated PYTHIA pp events, indicating no strong broadening of the radial jet structure in the reconstructed jets with R < 0.3. |
53. | Budnikov, D., Filchagin, S., Ilkaev, R., Kuryakin, A., Mamonov, A., Nazarenko, S., Punin, V., Tumkin, A., Vinogradov, Y., Vyushin, A., Zaviyalov, N. et al.,J /Ψ production and nuclear effects in P-Pb collisions at √SNN=5.02 TEV// Journal of High Energy Physics, 2014, Volume 2014, Issue 2, Р. 073. Russian Federal Nuclear Center VNIIEF, Sarov, Russia Inclusive J/Ψ production has been studied with the ALICE detector in p-Pb collisions at the nucleon-nucleon center of mass energy √sNN = 5.02TeV at the CERN LHC. The measurement is performed in the center of mass rapidity domains 2.03 < ycms < 3.53 and?4.46 < ycms < ?2.96, down to zero transverse momentum, studying the μ+μ? decay mode. In this paper, the J/Ψ production cross section and the nuclear modification factor RpPb for the rapidities under study are presented. While at forward rapidity, corresponding to the proton direction, a suppression of the J/Ψ yield with respect to binary-scaled pp collisions is observed, in the backward region no suppression is present. The ratio of the forward and backward yields is also measured differentially in rapidity and transverse momentum. Theoretical predictions based on nuclear shadowing, as well as on models including, in addition, a contribution from partonic energy loss, are in fair agreement with the experimental results. |
54. | Budnikov D., Filchagin S., Ilkaev R., Kuryakin A., Mamonov A., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al.,Suppression of ψ(2S) production in p-Pb collisions at (Formula presented.) // Journal of High Energy Physics, Volume 2014, Issue 12, p. 25Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast The ALICE Collaboration has studied the inclusive production of the charmonium state ψ(2S) in proton-lead (p-Pb) collisions at the nucleon-nucleon centre of mass energy (formula presented.) = 5.02 TeV at the CERN LHC. The measurement was performed at forward (2.03 < ycms< 3.53) and backward (−4.46 < ycms<−2.96) centre of mass rapidities, studying the decays into muon pairs. In this paper, we present the inclusive production cross sections σψ(2S), both integrated and as a function of the transverse momentum pT, for the two ycms domains. The results are compared to those obtained for the 1S vector state (J/ψ), by showing the ratios between the production cross sections, as well as the double ratios [σψ(2S)/σJ/ψ]pPb/[σψ(2S)/σJ/ψ]pp between p-Pb and proton-proton collisions. Finally, the nuclear modification factor for inclusive ψ(2S) is evaluated and compared to the measurement of the same quantity for J/ψ and to theoretical models including parton shadowing and coherent energy loss mechanisms. The results show a significantly larger suppression of the ψ(2S) compared to that measured for J/ψ and to models. These observations represent a clear indication for sizeable final state effects on ψ(2S) production |
55. | Nevmerzhitskiy N. V., Sotskov E. A., Sen'kovskiy E. D., Krivonos O. L., Polovnikov A. A., Levkina E. V., Frolov S. V., Abakumov S. A., Marmyshev V. V.,Study of the Reynolds Number Effect on the Process of Instability Transition Into the Turbulent Stage //Journal of Fluids Engineering, 2014, 136(9),P.091207)Russian Federal Nuclear Center VNIIEF, Sarov, Russia The results of the experimental study of the Reynolds number effect on the process of the Rayleigh–Taylor (R-T) instability transition into the turbulent stage are presented. The experimental liquid layer was accelerated by compressed gas. Solid particles were scattered on the layer free surface to specify the initial perturbations in some experiments. The process was recorded with the use of a high-speed motion picture camera. The following results were obtained in experiments: (1) Long-wave perturbation is developed at the interface at the Reynolds numbers Re <104. If such perturbation growth is limited by a hard wall, the jet directed in gas is developed. If there is no such limitation, this perturbation is resolved into the short-wave ones with time, and their growth results in gas-liquid mixing. (2) Short-wave perturbations specified at the interface significantly reduce the Reynolds number Re for instability to pass into the turbulent mixing stage. |
56. | AnnenkovV. I.a, GaraninS. G.a, KalmykovN. A.a, IvanovP. S.b, MochalovI. V.b, Sandulenko A. V.b, Sandyga S. V.b,A stimulated-Raman-scattering solid-state laser that radiates the second Stokes component as a master oscillator for a system of amplifiers based on atomic iodine // Journal of Optical Technology (A Translation of Opticheskii Zhurnal), Volume 81, Issue 2, 41671, Pp. 61-64.a All-Russia Scientific Research Institute of Experimental Physics, Russian Federal Nuclear Center, Sarov, Nizhniì Novgorod Oblast, Russian Federation b St. Petersburg National Research University of Information Technologies, Mechanics, and Optics, St. Petersburg, Russian Federation Various ways to create a master radiator at wavelength 1.315 μm are considered, and its optimum construction layout is chosen, based on obtaining efficient emission of the second Stokes component in a stimulated-Raman - scattering solid-state laser. An analysis is given of active crystals, and two solid-state pairs are proposed: laser crystal Gd3Ga5O12:Nd + a crystal of KY(WO4)2, and laser crystal LaF3:Nd + a crystal of KGd(WO4)2. A version of the layout with reduced losses is considered, based on Stokes components with simultaneous suppression of parasitic inversion dumping at a neodymium transition in the 1.3-μm region. The laser signal is amplified in a preamplifier stage based on iodine vapor, the gain was 150, and an output energy up to 60 mJ is obtained. |
57. | RodionovA. V.,AcomparisonoftheCABARETandMUSCL-typeschemes // MathematicalModelsandComputerSimulations, 2014, Vol. 6, No. 2, Pp. 203–225. Russian Federal Nuclear Center VNIIEF, Sarov, Russia The CABARET scheme is compared with some of those from the family of MUSCLtype schemes. Description and analysis of these schemes are presented as applied to the linear advection equation. For the CABARET scheme, a new formulation is proposed that can be treated as a modify cation of the MUSCL scheme. In MUSCLtype schemes, we consider three types of limiters, i. e., TVD, TVB, and the new NonOscillatory LowDissipative (NOLD) limiter. The schemes are tested on a set of linear problems (discontinuous and continuous profiles, uniform and nonuniform grids) and on the nonlinear blast wave problem. |
58. | V. I. Aksinin1, S. A. Antsiferov2, S. D. Velikanov2, A. Yu. Gerasimov2, I. V. Gostev2, SYuKazantsev1, V. V. Kalinovskii2, V. V. Konovalov2, I. G. Kononov1, V. N. Mikhalkin2, S. V. Podlesnykh1, I. V. Sevryugin2 andK. N. Firsov1 //Dischargeformationsystemsforgeneratingatomiciodineinapulse-periodicoxygen–iodinelaser//,QUANTUMELECTRON, 2014,44(1), pp. 89–93. 1AM. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow 2Russian Federal Nuclear Center 'All-Russian Research Institute of Experimental Physics', Sarov Generationcharacteristicsofapulse-periodicoxygen–iodinelaserwiththeelectro-dischargeproductionofatomiciodinewerecomparedwithinductivelystabilisededgedoranisotropic-resistivecathodesusedforignitionofthevolumedischarge. Thedischargewasinitiatedbytheradiationofabarrierdischargefromthesideofagridanode. Itwasfoundthatatequalspecificelectricalenergydepositionstothegas-dischargeplasma, thesystemwiththeanisotropic-resistivecathodeprovidesamorestableanduniformvolumedischargewiththepossibilityofvaryingthecompositionandpressureofworkingmixturesoverawiderangeandagreaterspecificextractionoflaserenergyisobserved(upto2.4JL-1).Atahighpulserepetitionrateoflaserpulses(50–100Hz)andlongdurationofthepulsetrains(longerthanaminute)thesurfaceofanisotropic-resistivecathodebecameeroded. |
59. | V. I.Aksinin1,S. A.Antsiferov2,S. D.Velikanov2,S. Yu. Kazantsev1,V. V.Kalinovskii2,V. V.Konovalov2,I. G.Kononov1,V. N.Mikhalkin2,S. V.Podlesnykh1,I. V.Sevryugin2andK. N.Firsov1,,Influenceofgastemperatureonself-sustainedvolumedischargecharacteristicsinworkingmixturesofarepetitivelypulsedСOIL,//QUANTUMELECTRON, 2014,44(2), Pp. 138–140. 1AM. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow 2Russian Federal Nuclear Center 'All-Russian Research Institute of Experimental Physics', Sarov Theinfluenceofgastemperatureonthecharacteristicsofaself-sustainedvolumedischargewasstudiedintheworkingmixturesofachemicaloxygen–iodinelaserwithpulsedelectricdischargeproductionofiodineatoms. Inexperiments, laserworkingmixturesweremodelledbythemixtureofairandiodideC2H5I. varyingthetemperatureofthemixturewiththeiodinecontentof~2.7%andinitialpressurep=12Torrfrom22°Cto96°C, thecurrentamplitudefallsby~12%,andattheinstantcorrespondingtoamaximalcurrentthevoltageraisesby~22%.Suchachangeinthedischargecharacteristicsisexplainedbyahigherrateofelectronattachmenttovibrationallyexcitediodidemoleculesatelevatedtemperatures. |
60. | S. D. Velikanov1, V. P. Danilov2, N. G. Zakharov1, N. N. Il'ichev2, S. Yu. Kazantsev2, V. P. Kalinushkin2, I. G. Kononov2, A. S. Nasibov3, M. I. Studenikin2, P. P. Pashinin2, K. N. Firsov2, P. V. Shapkin3andV. V. Shchurov1 , Fe2+: ZnSelaserpumpedbyanonchainelectric-dischargeHFlaseratroomtemperature //QUANTUMELECTRON, 2014,44(2), Pp. 141–144. 1Russian Federal Nuclear Center 'All-Russian Research Institute of Experimental Physics', Sarov, Nizhnii Novgorod region, Russian Federation 2A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow 3P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow ThecharacteristicsofaFe2+:ZnSelaserinaschemewithtransversepumpingbyanonchainelectric-dischargeHFlaseratroomtemperaturearestudied. DopingofZnSecrystalswithFe2+ionswasperformedbydiffusionsimultaneouslythroughtwosurfacesundertheconditionsofthermodynamicequilibrium. ItisfoundthattheFe2+:ZnSelaserpulsesaremodulatedbyshortspikes(3–7nsathalfmaximumatlowpumpenergies),whosenumberdecreasesandmodulationdepthincreasesasthepumpenergydecreasestoathresholdvalue. Alaserpulseenergyof30.6mJisachievedatapulsedurationathalfmaximumof~125ns(athighpumpenergies);thepossibilityofafurtherincreaseintheenergyofFe2+:ZnSelaserspumpedbynonchainHFlasersisdiscussed. |
61. | Bondarenko S. V.a, Novikova E. A.b, Dolgoleva G. V.a, Numerical analysis of radiation dynamics in a combined hohlraum in the X-ray opacity experiments on the 'ISKRA-5' laser facility // QUANTUM ELECTRON, 2014, Т. 44(3), Pp. 217-224. a Russian Federal Nuclear Centre, All-Russian Research Institute of Experimental Physics, prosp, Sarov, Nizhnii Novgorod region, Russian Federation b M. V. Keldysh Institute for Applied Mathematics, Russian Academy of Sciences, Moscow, Russian Federation We report the results of numerical analysis of radiation dynamics (laser absorption and X-ray generation) by using SNDLIRA code in a combined box used in the X-ray opacity measurements on the 'Iskra-5' facility (laser radiation wavelength, λ = 0.66 μm; laser pulse duration, τ0.5≈ 0.6 ns; and energy, 900 J). Combined boxes used in these experiments comprised three sections: two illuminators delivering laser radiation and a central diagnostic section with a test sample. We have proposed a scheme for step-by-step calculation of the heating dynamics of the sample under study in a three-section hohlraum. Two designs of a combined box, which differ in the ways the laser radiation is injected, are discussed. It is shown that the axial injection of the beams results in intense secondary laser irradiation of the illuminator edge which leads to its partial disruption and penetration of laser radiation into the central diagnostic section. In this case the sample under study is exposed to additional uncontrolled action of scattered laser ch an undesirable action may be avoided by using the lateral injection of the beams through four holes on the lateral side of the illuminators. For the latter case we have calculated the heating dynamics for the sample and found an optimal time delay for an X-ray probe pulse. |
62. | Volkov M. V., Garanin S. G., Dolgopolov Yu. V., Kopalkin A. V., Kulikov S. M., Sinyavin D. N., Starikov F. A., Sukharev S. A., Tyutin S. V., Khokhlov S. V., Chaparin D. A.,Phase locking of a seven-channel continuous wave fibre laser system by a stochastic parallel gradient algorithm // QUANTUM ELECTRON,2014, T.44(11),Pp. 1039-1042Institute of Experimental Physics, Federal Nuclear Center, Sarov, Russian Federation A seven-channel fibre laser system operated by the master oscillator-multichannel power amplifier scheme is the phase locked using a stochastic parallel gradient algorithm. The phase modulators on lithium niobate crystals are controlled by a multichannel electronic unit with the microcontroller processing signals in real time. The dynamic phase locking of the laser system with the bandwidth of 14 kHz is demonstrated, the time of phasing is 3-4 ms. |
63. | Gorbatenko M. V., Neznamov V. P., Stationary Bound States of Dirac Particles in Collapsar Fields // Physics of Particles and Nuclei, 2014, Vol.45, pp. 220-222 Russian Federal Nuclear Center–VNIIEF and Sarov Institute of Physics and Technology, Sarov, Russia It is the first time stationary bound states of elementary spin 1/2 particles that do not decay with time are obtained for a Schwarzschild gravitational field using a self-conjugate Hamiltonian with a flat scalar product in a wide range of gravitational coupling constant. In order to obtain a discrete energy spectrum, we introduce a boundary condition such that the current density of Dirac particles near the «event horizon» is zero. |
64. | Dubinov A. E.1,2, Maksimov A. N.1, Mironenko M. S.1,2, Pylayev N. A.1, Selemir V. D.1,2, Glow discharge based device for solving mazes // Physics of Plasmas, 2014, Volume 21, №9, P.093503 1 Russian Federal Nuclear Center VNIIEF, Sarov, Russia 2 Sarov Physical-Technical Institute, Sarov, Russia A glow discharge based device for solving mazes has been designed and tested. The device consists of a gas discharge chamber and maze-transformer of radial-azimuth type. It allows changing of the maze pattern in a short period of time (within several minutes). The device has been tested with low pressure air. Once switched on, a glow discharge has been shown to find the shortest way through the maze from the very first attempt, even if there is a section with potential barrier for electrons on the way. It has been found that ionization waves (striations) can be excited in the maze along the length of the plasma channel. The dependency of discharge voltage on the length of the optimal path through the maze has been measured. A reduction in discharge voltage with one or two potential barriers present has been found and explained. The dependency of the magnitude of discharge ignition voltage on the length of the optimal path through the maze has been measured. The reduction of the ignition voltage with the presence of one or two potential barriers has been observed and explained. |
65. | Dubinov A. E.; Kitayev I. N., New solutions of the Zakharov's equation system for quantum plasmas in form of nonlinear bursts lattice //Physics of Plasmas, Volume 21, №2, Р.022309 Russian Federal Nuclear Center–VNIIEF and Sarov Institute of Physics and Technology, Sarov, Russia New multiplicative solutions of the Zakharov’s quantum system of equations using the separation of variables method are found. The found solutions are interpreted as spatial-periodical lattices of non-linear plasma bursts. It is shown that the bursts could be both symmetrical and asymmetrical by an electric field. |
66. | Dubinov, A. E., Kitaev, I. N., Non-linear Langmuir waves in a warm quantum plasma // Physics of Plasmas, 2014, Volume 21, № 1, Р. 102105 Russian Federal Nuclear Center-The All-Russian Research Institute of Experimental Physics, Sarov, Nizhny Novgorod oblast, Russian Federation A non-linear differential equation describing the Langmuir waves in a warm quantum electron-ion plasma has been derived. Its numerical solutions of the equation show that ordinary electronic oscillations, similar to the classical oscillations, occur along with small-scale quantum Langmuir oscillations induced by the Bohm quantum force. |
67. | BudnikovD., FilchaginS., IlkaevR., Kuryakin A., Mamonov A., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al., Multiplicity dependence of pion, kaon, proton and lambda production in p–Pb collisions at
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68. | BudnikovD., FilchaginS., IlkaevR., KuryakinA., MamonovA., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al., Multi-strange baryon production at mid-rapidity in Pb-Pb collisions at √sNN=2.76 TeV // Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics,2014, Volume 728, Issue 1, Pages 216-227Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast The production of ξ- and ω- baryons and their anti-particles in Pb-Pb collisions at √sNN= 2.76 TeV has been measured using the ALICE detector. The transverse momentum spectra at mid-rapidity (|y| < 0.5) for charged ξ and ω hyperons have been studied in the range 0.6 < PT< 8.0 GeV/c and 1.2 < PT < 7.0 GeV/c, respectively, and in several centrality intervals (from the most central 0-10% to the most peripheral 60-80% collisions). These spectra have been compared with the predictions of recent hydrodynamic models. In particular, the Kraków and EPOS models give a satisfactory description of the data, with the latter covering a wider PT range. Mid-rapidity yields, integrated over PT, have been determined. The hyperon-to-pion ratios are similar to those at RHIC: they rise smoothly with centrality up to (Npart) ~ 150 and saturate thereafter. The enhancements (yields per participant nucleon relative to those in pp collisions) increase both with the strangeness content of the baryon and with centrality, but are less pronounced than at lower energies. |
69. | BudnikovD., FilchaginS., IlkaevR., KuryakinA., MamonovA., NazarenkoS., PuninV., TumkinA., VinogradovY., VyushinA., Zaviyalov N. et al., Centrality, rapidity and transverse momentum dependence of J/ψ suppression in Pb-Pb collisions at √sNN= 2.76TeV // Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics,2014, Volume 734,Pp. 314-327Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast The inclusive J/ψ nuclear modification factor (RAA) in Pb-Pb collisions at √sNN=2.76TeV has been measured by ALICE as a function of centrality in thee +e - decay channel at mid-rapidity (|y| < 0.8) and as a function of centrality, transverse momentum and rapidity in theμ +μ - decay channel at forward-rapidity (2.5 < y < 4). The J/ψ yields measured in Pb-Pb are suppressed compared to those in pp collisions scaled by the number of binary collisions. TheRAAintegrated over a centrality range corresponding to 90% of the inelastic Pb-Pb cross section is 0.72 ± 0.06(stat.) ± 0.10(syst.) at mid-rapidity and 0.58 ± 0.01(stat.) ± 0.09(syst.) at forward-rapidity. At low transverse momentum, significantly larger values ofRAAare measured at forward-rapidity compared to measurements at lower energy. These features suggest that a contribution to the J/ψ yield originates from charm quark (re)combination in the deconfined partonic medium. |
70. | BudnikovD., FilchaginS., IlkaevR., KuryakinA., MamonovA., NazarenkoS., PuninV., TumkinA., VinogradovY., VyushinA., Zaviyalov N. et al., Production of charged pions, kaons and protons at large transverse momenta in pp and Pb-Pb collisions at √sNN=2.76 TeV // Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2014, Volume 736,Pp. 196-207Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast Transverse momentum spectra ofπ ±,K ±and p(p-) up topT= 20 GeV/c at mid-rapidity in pp, peripheral (60-80%) and central (0-5%) Pb-Pb collisions at √sNN=2.76 TeV have been measured using the ALICE detector at the Large Hadron Collider. The proton-to-pion and the kaon-to-pion ratios both show a distinct peak atpT≈ 3 GeV/c in central Pb-Pb collisions. Below the peak, pT< 3 GeV/c, both ratios are in good agreement with hydrodynamical calculations, suggesting that the peak itself is dominantly the result of radial flow rather than anomalous hadronization processes. ForpT> 10 GeV/c particle ratios in pp and Pb-Pb collisions are in agreement and the nuclear modification factors forπ ±,K ±and p(p-) indicate that, within the systematic and statistical uncertainties, the suppression is the same. This suggests that the chemical composition of leading particles from jets in the medium is similar to that of vacuum jets. |
71. | Budnikov D., Filchagin S., Ilkaev R., Kuryakin A., Mamonov A., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al.,Beauty production in pp collisions at s=2.76 TeV measured via semi-electronic decays // Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2014, Volume 738, Pp. 97-108 Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast The ALICE Collaboration at the LHC reports measurement of the inclusive production cross section of electrons from semi-leptonic decays of beauty hadrons with rapidity |y|<0.8 and transverse momentum 1<pT<10 GeV/c, in pp collisions at s=2.76 TeV. Electrons not originating from semi-electronic decay of beauty hadrons are suppressed using the impact parameter of the corresponding tracks. The production cross section of beauty decay electrons is compared to the result obtained with an alternative method which uses the distribution of the azimuthal angle between heavy-flavour decay electrons and charged hadrons. Perturbative QCD predictions agree with the measured cross section within the experimental and theoretical uncertainties. The integrated visible cross section, σb→e=3.47±0.40(stat)-1.33+1.12(sys)±0.07(norm) μb, was extrapolated to full phase space using Fixed Order plus Next-to-Leading Log (FONLL) calculations to obtain the total bb production cross section, σbb=130±15.1(stat)-49.8+42.1(sys)-3.1+3.4(extr)±2.5(norm)±4.4(BR) μb. |
72. | Budnikov D., Filchagin S., Ilkaev R., Kuryakin A., Mamonov A., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al.,Suppression of γ{hooked}(1S) at forward rapidity in Pb-Pb collisions at sNN=2.76 TeV // Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics,2014, Volume 738, Pp. 361-372Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast We report on the measurement of the inclusive γ{hooked}(1S) production in Pb-Pb collisions at sNN=2.76 TeV carried out at forward rapidity (2.5<y<4) and down to zero transverse momentum using its μ+μ- decay channel with the ALICE detector at the Large Hadron Collider. A strong suppression of the inclusive γ{hooked}(1S) yield is observed with respect to pp collisions scaled by the number of independent nucleon-nucleon collisions. The nuclear modification factor, for events in the 0-90% centrality range, amounts to 0.30±0.05(stat)±0.04(syst). The observed γ{hooked}(1S) suppression tends to increase with the centrality of the collision and seems more pronounced than in corresponding mid-rapidity measurements. Our results are compared with model calculations, which are found to underestimate the measured suppression and fail to reproduce its rapidity dependence. |
73. | Budnikov D., Ilkaev R., Kuryakin A., Mamonov A., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al.,Freeze-out radii extracted from three-pion cumulants in pp, p-Pb and Pb-Pb collisions at the LHC // Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2014, Volume 739, Pp. 139-151Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast In high-energy collisions, the spatio-temporal size of the particle production region can be measured using the Bose-Einstein correlations of identical bosons at low relative momentum. The source radii are typically extracted using two-pion correlations, and characterize the system at the last stage of interaction, called kinetic freeze-out. In low-multiplicity collisions, unlike in high-multiplicity collisions, two-pion correlations are substantially altered by background correlations, e. g. ch correlations can be suppressed using three-pion cumulant correlations. We present the first measurements of the size of the system at freeze-out extracted from three-pion cumulant correlations in pp, p-Pb and Pb-Pb collisions at the LHC with ALICE. At similar multiplicity, the invariant radii extracted in p-Pb collisions are found to be 5-15% larger than those in pp, while those in Pb-Pb are 35-55% larger than those in p-Pb. Our measurements disfavor models which incorporate substantially stronger collective expansion in p-Pb as compared to pp collisions at similar multiplicity. |
74. | BudnikovD. etal.,MeasurementofpromptD - mesonproductioninp-PbcollisionsatsNN =5.02TeV // Physical Review Letters, 2014, Volume 113, Issue 23, Article number 232301 Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast The pT-differential production cross sections of the prompt charmed mesons D0, D+, D*+, and Ds+ and their charge conjugate in the rapidity interval -0.96<ycms<0.04 were measured in p-Pb collisions at a center-of-mass energy sNN=5.02TeV with the ALICE detector at the LHC. The nuclear modification factor RpPb, quantifying the D-meson yield in p-Pb collisions relative to the yield in pp collisions scaled by the number of binary nucleon-nucleon collisions, is compatible within the 15%-20% uncertainties with unity in the transverse momentum interval 1<pT<24GeV/c. No significant difference among the RpPb of the four D-meson species is observed. The results are described within uncertainties by theoretical calculations that include initial-state effects. The measurement adds experimental evidence that the modification of the momentum spectrum of D mesons observed in Pb-Pb collisions with respect to pp collisions is due to strong final-state effects induced by hot partonic matter. |
75. | Budnikov D., Filchagin, S. et al.,Exclusive J /ψ photoproduction off protons in ultraperipheral p - Pb collisions at sNN =5.02TeV // Physical Review Letters,2014, Volume 113, Issue 23, Article number 232504Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast We present the first measurement at the LHC of exclusive J/ψ photoproduction off protons, in ultraperipheral proton-lead collisions at sNN=5.02TeV. Events are selected with a dimuon pair produced either in the rapidity interval, in the laboratory frame, 2.5<y<4 (p-Pb) or -3.6<y<-2.6 (Pb-p), and no other particles observed in the ALICE acceptance. The measured cross sections σ(γ+p→J/ψ+p) are 33.2±2.2(stat)±3.2(syst)±0.7(theor)nb in p-Pb and 284±36(stat)-32+27(syst)±26(theor)nb in Pb-p collisions. We measure this process up to about 700 GeV in the γp center of mass, which is a factor of two larger than the highest energy studied at HERA. The data are consistent with a power law dependence of the J/ψ photoproduction cross section in γp energies from about 20 to 700 GeV, or equivalently, from Bjorken x scaling variable between ~2×10-2 and ~2×10-5, thus indicating no significant change in the gluon density behavior of the proton between HERA and LHC energies. |
76. | Budnikov D., Filchagin S., Ilkaev R., Kuryakin A., Mamonov A., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al., Two - and three-pion quantum statistics correlations in Pb-Pb collisions at SNN = 2.76 TEV at the cern large hadron collider // Physical Review C - Nuclear Physics, 2014, Volume 89. Issue 2, Article number 024911. Russian Federal Nuclear Center, Sarov, Nizhniy Novgorod region, Russia Correlations induced by quantum statistics are sensitive to the spatiotemporal extent as well as dynamics of particle-emitting sources in heavy-ion collisions. In addition, such correlations can be used to search for the presence of a coherent component of pion production. Two - and three-pion correlations of same and mixed charge are measured at low relative momentum to estimate the coherent fraction of charged pions in Pb-Pb collisions at sNN=2.76 TeV at the CERN Large Hadron Collider with ALICE. The genuine three-pion quantum statistics correlation is found to be suppressed relative to the two-pion correlation based on the assumption of fully chaotic pion emission. The suppression is observed to decrease with triplet momentum. The observed suppression at low triplet momentum may correspond to a coherent fraction in charged-pion emission of 23%±8% |
77. | BudnikovD., FilchaginS., IlkaevR., KuryakinA., MamonovA., NazarenkoS., PuninV., TumkinA., Vinogradov Y., Vyushin A., Zaviyalov N. et al., Azimuthal anisotropy of D - meson production in Pb-Pb collisions at sNN =2.76 TeV // Physical Review C - Nuclear Physics, Volume 90, Issue 3, Article number 034904Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast The production of the prompt charmed mesons D0, D+, and D*+ relative to the reaction plane was measured in Pb-Pb collisions at a center-of-mass energy per nucleon-nucleon collision of sNN=2.76TeV with the ALICE detector at the CERN Large Hadron Collider. D mesons were reconstructed via their hadronic decays at central rapidity in the transverse-momentum (pT) interval 2-16 GeV/c. The azimuthal anisotropy is quantified in terms of the second coefficient v2 in a Fourier expansion of the D-meson azimuthal distribution and in terms of the nuclear modification factor RAA, measured in the direction of the reaction plane and orthogonal to it. The v2 coefficient was measured with three different methods and in three centrality classes in the interval 0%-50%. A positive v2 is observed in midcentral collisions (30%-50% centrality class), with a mean value of 0.204-0.036+0.099 (tot. unc.) in the interval 2<pT<6GeV/c, which decreases towards more central collisions (10%-30% and 0%-10% classes). The positive v2 is also reflected in the nuclear modification factor, which shows a stronger suppression in the direction orthogonal to the reaction plane for midcentral collisions. The measurements are compared to theoretical calculations of charm-quark transport and energy loss in high-density strongly interacting matter at high temperature. The models that include substantial elastic interactions with an expanding medium provide a good description of the observed anisotropy. However, they are challenged to simultaneously describe the strong suppression of high-pT yield of D mesons in central collisions and their azimuthal anisotropy in noncentral collisions. |
78. | Budnikov D., Filchagin S., Ilkaev R., Kuryakin A., Mamonov A., Nazarenko S., Punin V., Tumkin A., Vinogradov Y., Vyushin A., Zaviyalov N. et al., Multiparticle azimuthal correlations in p - Pb and Pb-Pb collisions at the CERN Large Hadron Collider// Physical Review C - Nuclear Physics, 2014, Volume 90, Issue 5, Article number 054901Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast Measurements of multiparticle azimuthal correlations (cumulants) for charged particles in p-Pb at sNN=5.02 TeV and Pb-Pb at sNN=2.76 TeV collisions are presented. They help address the question of whether there is evidence for global, flowlike, azimuthal correlations in the p-Pb parisons are made to measurements from the larger Pb-Pb system, where such evidence is established. In particular, the second harmonic two-particle cumulants are found to decrease with multiplicity, characteristic of a dominance of few-particle correlations in p-Pb collisions. However, when a |Δη| gap is placed to suppress such correlations, the two-particle cumulants begin to rise at high multiplicity, indicating the presence of global azimuthal correlations. The Pb-Pb values are higher than the p-Pb values at similar multiplicities. In both systems, the second harmonic four-particle cumulants exhibit a transition from positive to negative values when the multiplicity increases. The negative values allow for a measurement of v2{4} to be made, which is found to be higher in Pb-Pb collisions at similar multiplicities. The second harmonic six-particle cumulants are also found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find v2{4} ≈ v2{6}≠0 which is indicative of a Bessel-Gaussian function for the v2 distribution. For very high-multiplicity Pb-Pb collisions, we observe that the four - and six-particle cumulants become consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and Pb-Pb are measured. These are found to be similar for overlapping multiplicities, when a |Δη|>1.4 gap is placed. |
79. | Babich L. P.a, Bochkov E. I.a, Kutsyk I. M.a, Rassoul H. K.b,Analysis of fundamental interactions capable of producing neutrons in thunderstorms // Physical Review D - Particles, Fields, Gravitation and Cosmology, 2014, Volume 89, Issue 9, Article number 093010. a Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblast b Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, United States Elementary processes capable of producing neutrons in thunderstorms are analyzed. Efficiency is evaluated of nuclear fusion, photonuclear reaction, electrodisintegration, and reaction inverse to the β-decay. An extraordinary strong electric field is required for nuclear fusion to occur in a lightning channel. The inverse to β-decay reactions are too weak. The generation of neutrons in a thunderstorm is connected with photonuclear and, to a lesser degree, with electrodisintegration reactions. |
80. | NeznamovV. P., SafronovI. I.,Newmethodforsolvingthe 'Z> 137' problem and determining hydrogen-like energy levels// Physics-Uspekhi, 2014, Т. 57, № 2, Рр. 189-193. Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblast A new method for including finite nuclear size effects is suggested to overcome the “Z> 137 catastrophe” encountered in solving the Dirac equation for an electron in the field of a point chargeZe. In this method, the boundary condition for the numerical solution of the equations for the Dirac radial wave functions is taken to be that the components of the electron current density are zero at the boundary of the nucleus. As a result, for all of the nuclei of the periodic table the calculated energy levels practically coincide with those obtained in a standard way from the Dirac equation for a Coulomb point charge potential. ForZ> 105, the calculated energy level functionsE(Z)prove to be smooth and monotonic. The ground energy level reachesE = −mc2(i. e., the electron drops into the nucleus) at Zc= 178. The proposed method for accounting for the finite size of nuclei can be useful in numerically calculating the energy levels of many-electron atoms. |
81. | Fomin V. N.a, Nikitin V. M.b, Zhbakov E. B.c, Sautkin V. A.d, And Suyazova E. K.e, Optimal processing of noisy images in a photodetector with limited dynamic range// Physics of Wave Phenomena, 2014, Т. 22, № 2, Pp. 125-131. a Prokhorov General Physics Institute, Russian Academy of Sciences, , Moscow, Russian Federation b National Research University Belgorod State University, Belgorod, Russian Federation c Moscow Humanitarian Economic Institute, Nizhny Novgorod, Russian Federation d JSC Krasnogorsky Zavod, Krasnogorsk, Moscow Oblast, Russian Federation e Russian Federal Nuclear Center All-Russian Research Institute of Experimental Physics, Sarov, Nizhny Novgorod Oblast, Russian Federation A study aimed at optimizing noisy image processing under conditions of strong additive noise has been performed. An algorithm of optimal signal processing was developed and a possibility of improving image quality due to the subtraction of excess additive noise (which limits the photodetector dynamic range) was substantiated. The possibility of technical implementation of noise subtraction due to forced recombination of charge carriers in the photodetector is experimentally confirmed. The proposed approach to design processing systems makes it possible to improve the quality of recorded images under noisy conditions without any changes in the photodetector design. |
82. | Brendel V. M.a, Bukin V. V.a, Garnov S. V.ab, Bagdasarov V. Kh. a, Sadovskii S. P.a, Chizhov P. A.a, Dolmatov T. V.a, Loza O. T.a, Litvin V. O.c, Tarakanov V. P.d, Terekhin V. A.e, Trutnev Yu. A.e, Superluminal source of directional pulsed wideband electromagnetic radiation// Physics of Wave Phenomena, 2014, Т. 22, № 4, Pp. 219-222. a Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow, Russian Federation b National Research Nuclear University (Moscow Engineering Physics Institute), Moscow, Russian Federation c PeoplesT Friendship University of Russia, Moscow, Russian Federation d Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow, Russian Federation e Russian Federal Nuclear Center-The All-Russian Research Institute of Experimental Physics, Sarov, Nizhny Novgorod oblast, Russian Federation A photoemission source of directional pulsed wideband electromagnetic radiation in the microwave region is developed, and the time profile of the generated pulse is investigated. The source is a vacuum photodiode of a parabolic shape in which a Cherenkov radiation pulse is formed by an electron current wave excited by an incident laser pulse and propagating along the surface of the anode mesh with a phase velocity higher than the speed of light. |
83. | Semena N. a, Pavlinsky M. a, Buntov M. a, Serbinov D. a, Gurova E. a, Tambov V. a, Roiz I. b, Garin M. b, Lazarchuk V. b, Zaytcev A. c, Martunov V. c, Shabarchin A. c, Sokolov A. d,ART-XC/SRG: Results of thermo-vacuum tests // Proceedings of SPIE - The International Society for Optical Engineering,2014,Volume 9144, Article number 91444Ta Space Research Institute, IKI, Moscow, Russian Federation b Russian Federal Nuclear Center, VNIIEF, Sarov, Russian Federation c Lavochkin Association, LA, Khimki, Russian Federation d NPO Molniya, Moscow, Russian Federation ART-XC - a medium-x-ray-energy survey instrument for SRG project is being developed in Russia. Space Research institute (IKI) and Federal Nuclear Center (VNIIEF) has developed and tested the STM (Structural and Thermal Model) of ART-XC/SRG Instrument. The STM was tested in a 40 m3vacuum chamber, equipped with black cryogenic screens, cooled by liquid nitrogen. During the tests various thermal telescope modes were simulated. In particular we have simulated emergency mode, when mirrors heaters were switched-off. During the tests temperature of instrument's structure was controlled by 64 independent sensors. Stability of optical axis of mirror systems was also measured. STM test has shown that temperature of mirror system was lower than required, temperature of detectors met the requirements. The test also confirmed geometrical stability of the carbon fiber housing despite of significant temperature gradients. Additional experiments with two mirror systems, each containing a full set of simple nickel shells, were performed. In these experiments we have measured longitudinal and transverse temperature gradients of mirror systems. Next thermovacuum tests of the qualification model of the ART-XC instrument are being prepared. Results of STM tests are presented in this paper. |
84. | PavlinskyM. a, AkimovV. a, LevinV. a, LapshovI. a, TkachenkoA. a, SemenaN. a, BuntovM. a, GlushenkoA. a, ArefievV. a, YaskovichA. a, SunyaevR. a, ChurazovE. a, GilfanovM. a, GrebenevS. a, SazonovS. a, RevnivtsevM. a, LutovinovA. a, MolkovS. a, KudelinM. a, DrozdovaT. a, GaraninS. b, GrigorovichS. b, LitvinD. b, LazarchukV. b, RoizI. b, GarinM. b, BabyshkinV. c, LomakinI. c, MenderovA. c, MoskvinovD. c, GubarevM. d, RamseyB. d, KilaruK. d, O'DellS. L.d, KolodziejczakJ. d, ElsnerR.de,StatusofART-XC/SRGinstrument // ProceedingsofSPIE - TheInternationalSocietyforOpticalEngineering,2014, Volume 9144, Articlenumber 91441Ua Space Research Institute, Russian Federation b All-Russian Scientific Research Institute for Experimental Physics, VNIIEF, Russian Federation c Lavochkin Association, Russian Federation d MPI Für Astrophysik, Germany e NASA Marshall Space Flight Ctr, United States Spectrum Roentgen Gamma (SRG) is an X-ray astrophysical observatory, developed by Russia in collaboration with Germany. The mission will be launched in March 2016 from Baikonur, by a Zenit rocket with a Fregat booster and placed in a 6-month-period halo orbit around L2. The scientific payload consists of two independent telescopes - a softx - ray survey instrument, eROSITA, being provided by Germany and a medium-x-ray-energy survey instrument ART-XC being developed by Russia. ART-XC will consist of seven independent, but co-aligned, telescope modules. The NASA Marshall Space Flight Center (MSFC) is fabricating the flight mirror modules for the ART-XC/SRG. Each mirror module will be aligned with a focal plane CdTe double-sided strip detector which will operate over the energy range of 6â'30 keV, with an angular resolution of <1 2, a field of view of ~34 2 and an expected energy resolution of about 10% at 14 keV. |
85. | SosninE. A.ab, TarasenkoV. F.a, PikulevA. A.c, Thermodynamicapproachtodeterminationofthedegreeofinhomogeneityofa capacitive discharge// Russian Physics Journal, 2014, Т. 56, № 11, Pp. 1258-1261. a National Research Tomsk State University, Tomsk, Russian Federation b High-Current Electronics Institute of the Siberian Branch of the Russian Academy of Sciences, Tomsk, Russian Federation c Russian Federal Nuclear Center - All-Russian Scientific-Research Institute for Experimental Physics, Sarov, Russian Federation It is shown in the case of capacitive discharge excilamps that the thermal power of the discharge is proportional to the volume filling coefficient of the discharge. It is proposed to treat the found phenomenon as an analog of the effect of the normal current density of a barrier discharge. |
86. | Chuvil'deev V. N.a, Nokhrin A. V.a, Baranov G. V.b, Boldin M. S.a, Moskvicheva A. V.a, Sakharov N. V.a, Kotkov D. N.a, Lopatin Y. G.a, Belov V. Y.b, Blagoveshchenskii Y. V.c, Kozlova N. A.a, Konychev D. A.a, Isaeva N. V.c, Sintering of nano - and ultradispersed mechanically activated W-Ni-Fe powders and the manufacture of ultrahigh-strength heavy tungsten alloys // Russian Metallurgy (Metally), 2014, Volume 2014, Issue 3,Pages 215-228 a Research Physicotechnical Institute, Nizhni Novgorod State University, Nizhni Novgorod, Russian Federation b Russian Federal Nuclear Center-All-Russia Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, Russian Federation c Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Moscow, Russian Federation The structure and mechanical properties of nano - and ultradispersed mechanically activated heavy W-Ni-Fe and W-Ni-Fe-Co tungsten alloys (VNZh and VNZhK alloys, respectively) are studied. Mechanically activated nano - and ultradispersed charge powders are sintered by free sintering (thermally activated) and spark plasma sintering. The dependence of the density of the alloys made of the mechanically activated powders on the sintering temperature is found to have a nonmonotonic character with a maximum corresponding to the optimum sintering temperature. It is shown that an increase in the mechanical activation time and the acceleration of the milling bodies during mechanical activation lead to a decrease in the alloy particle size and the formation of nonequilibrium solid solutions and are accompanied by a decrease in the optimum sintering temperature of heavy tungsten alloys. Ultrahigh-strength tungsten alloys the mechanical properties of which are substantially higher than those of standard coarse-grained analogs are fabricated due to the optimization of the conditions of ball milling and high-rate spark plasma sintering of W-Ni-Fe powders. |
87. | Gerasimov S. I.abc, Kanygin I. I.ab, Kikeev V. A.c, Gerasimova R. V.a, Totyshev K. V.b, Golubev V. K.b, Numerical and experimental visualization of supersonic flow around control shields on segment-conical bodies of revolution// Scientific Visualization,2014, Volume 6, Issue 3, 2014, Pp. 55-67a Sarov Physics and Technical Institute, National Research Nuclear University MEPHI, Russian Federation b Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics, Sarov, Russian Federation c Nizhny Novgorod State Technical University N. a. R. E. Alekseev, Russian Federation For control, braking and stabilization of supersonic and hypersonic aircraft with more and more applications are shield controls. The use of such controls, allow for a fairly wide range to change the aerodynamic coefficients of the aircraft. At supersonic flight velocities there is a complex pattern of the flow around aircraft, especially in the areas of location of the shields, where separated flow occurs. Obtaining realistic data for separated flows in various conditions, especially at high angles of attack is possible now only with the use of experimental methods. At the same time, existing numerical methods enable one to correctly analyze the pattern about the aircraft as a whole and be able to get acceptable results on determination of aerodynamic coefficients in a wide range of flow conditions. Good agreement of these results with experimental data of a single measurement allows the prediction to determine the values of these coefficients at any arbitrary conditions of flow. Below are the results of the study of supersonic flow past the series models of hypersonic aircraft. The tested models were of different shape and size of control shields. |
88. | Sosnin E. A.ab, Pikulev A. A.c, New marker for determining the degree of inhomogeneity of capacitive and barrier discharges // Technical Physics, Volume 59, Issue 12, 17 December 2014, Pages 1801-1804a Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences, Tomsk, Russian Federation b State Higher Education Enterprise National Research Tomsk State University, Tomsk, Russian Federation c Russian Federal Nuclear Center All-Russian Research Institute of Experimental Physics, Sarov, Nizhni Novgorod oblast, Russian Federation A new thermodynamic approach to estimating the degree of nonuniformity of filling of the excimer lamp bulb with the discharge plasma is proposed for refining the results of numerical simulation of generation of radiation in the excilamp plasmas. It is shown that the thermal power of the discharge in a capacitive-discharge XeCl excilamp is proportional to the discharge filling factor. For a barrier-discharge XeCl excilamp, it is shown that the discrepancy between the efficiencies obtained by numerical simulation of an “ideal” discharge system and in the experiment can be explained taking into account the discharge filling factor of the cuvette. |
89. | Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov, Nizhni Novgorod oblast The results of modeling several laboratory experiments, including a large class of advanced experimental studies of turbulent flows, are presented. The results of the Meshkov’s “cylindrical” and “planar” experiments on the confluence of two zones of turbulent mixing, the experiments of Poggi, Barre, and Uberoi have been carried out using the Nikiforov’s model. The presented results attest that the Nikiforov’s model qualitatively describes the considered class of flows if the mean gas-dynamic quantities are computed with a high accuracy in the technique, and the width of the front of the finite-difference shock wave does not depend on the size of the computational grid cell. |
90. | Boiko A. V.a, Nechepurenko Y. M.b, Zhuchkov R. N.c, Kozelkov A. S.c,Laminar-turbulent transition prediction module for LOGOS package // Thermophysics and Aeromechanics, 2014, Volume 21, Issue 2, Pp 191-210 aKhristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russian Federation b Institute of Numerical Mathematics of RAS, Moscow, Russian Federation c Russian Federal Nuclear Center-All-Russian Research Institute of Experimental Physics, Sarov, Nizhny Novgorod Region, Russian Federation The present work is devoted to a description and substantiation of an original module for computing the location of laminar-turbulent transition in subsonic boundary layer flows, which is based on the eN-method and enables more accurate computations of the flow around bodies in the presence of the so-called natural transition to turbulence in the boundary layer. A combined work of the module and the RANS solver from the aerodynamic part of the LOGOS package is demonstrated by the example of the flow past a flat plate. The obtained computed locations of the beginning and the end of the laminar-turbulent transition coincide with known reference values. |
91. | Lin E. E., Asymptotic Models for Studying Kinetics of Formation of Compact Objects with Strong Internal Bonds // World Journal of Mechanics, 2014, No.4, Pp.170-196 Russian Federal Nuclear Center VNIIEF, Sarov, Russia An asymptotic method has been developed for investigation of kinetics of formation of compact objects with strong internal bonds. The method is based on the uncertainty relation for a coordinate and a momentum in space of sizes of objects (clusters) with strongly pronounced collective quantum properties resulted from exchange interactions of various physical nature determined by spatial scales of the processes under consideration. The proposed phenomenological approach has been developed by analogy with the all-known ideas about coherent states of quantum mechanical oscillator systems for which a product of coordinate and momentum uncertainties (dispersions) accepts the value, which is minimally possible within uncertainty relations. With such an approach the leading processes are oscillations of components that make up objects, mainly: collective nucleon oscillations in a nucleus and phonon excitations in a mesostructure crystal lattice. This allows us to consider formation and growth of subatomic and mesoscopic objects in the context of a single formalism. The proposed models adequately describe characteristics of formation processes of nuclear matter clusters as well as mesoscopic crystals having covalent and quasi-covalent bonds between atoms. |
92. | BogdanovE. N., Belskiy V. M., Mikhaylov A. L., Rodionov A. V., Sedov A. A., Khvorostin V. N., Microwave diagnostics of shock-wave and detonation processes // Zel'dovich Memorial: Accomplishments in the combustion science in the last decade Edited by A. A. Borisov and S. M. Frolov, 2014, С. 175-177. Russian Federal Nuclear Center VNIIEF, Sarov, Russia A method for measuring the parameters of shock-wave and detonation processes using a microwave interferometer is proposed. The experimental technique used in the study and the employed method of processing experimental data are described. Examples of experimental studies carried out using a radio interferometer of the three-millimeter range are considered. |
Сборник рефератов статей сотрудников РФЯЦ-ВНИИЭФ, опубликованных в иностранных журналах и российских журналах, выпускаемых на английском языке в 2014 г
, GolubevA. A.a, BogdanovA. V.a, DemidovV. S.a, DemidovaE. V.a, LadyginaE. M.a, MarkovN. V.a, SkachkovV. S.a, SmirnovG. N.a, RudskoyI. V.a, KuznetsovA. P.a, KhudomyasovA. V.a, SharkovB. Yu. ab, DudinS. V.c, KolesnikovS. A.c, MintsevV. B.c, NikolaevD. N.c, TernovoiV. Ya. c, UtkinA. V.c, YurievD. S.c, ShilkinN. S.c, FortovV. E.c, TurtikovV. I.d, BurtsevV. V.e, ZhernokletovM. V.e, ZavialovN. V.e, KartanovS. A.e, MikhailovA. L.e, RudnevA. V.e, Tatsenko, M. V.e, VarentsovD. V.f, ShestovL. M.f,TWAC-ITEPprotonmicroscopyfacility // InstrumentsandExperimentalTechniques. 2014. Т. 57. № 1. Рр. 1-10.
// Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2014, Volume 728, Issue 1, Pages 25-38
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