Сборник рефератов статей сотрудников РФЯЦ-ВНИИЭФ, опубликованных в
иностранных журналах, на Web-сайтах и российских журналах, выпускаемых на
английском языке в 2013 г.
Belkov, S.A. a, Garanin, S.G. a, Epatko, I.V. b, Serov, R.V. b, Voronich, I.N. a, Formation of nonlinear
holographic images in a system of periodically located nonlinear mediums
EPJ Web of Conferences, 2013, 59, art. no. 08009
a
b
FSUE RFNC – VNIIEF, 37, Sarov, Mira Ave, Nizhny Novgorod region 607188, Russian Federation
A.M. Prokhorov Institute of General Physics, RAS, 38 Vavilov St., 119991 Moscow, Russia
The formation of nonlinear holographic images in a system of periodically located nonlinear mediums is
studied. Analytical expressions which describe the magnitudes and locations of intensity maximums
depending on the corresponding image number are derived. Comparison with numerical calculation results
is presented.
Statsenko, V.P., Yanilkin, Yu.V., Zhmaylo, V.A., Direct numerical simulation of turbulent mixing
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences,
2013, 371 (2003), art. no. 20120216
RFNC-VNIIEF, 607188 Sarov
The results of three-dimensional numerical simulations of turbulent flows obtained by various authors are
reviewed. The paper considers the turbulent mixing (TM) process caused by the development of the main
types of instabilities: those due to gravitation (with either a fixed or an alternating-sign acceleration), shift
and shock waves. The problem of a buoyant jet is described as an example of the mixed-type problem.
Comparison is made with experimental data on the TM zone width, profiles of density, velocity and
turbulent energy and degree of homogeneity. © 2013 The Author(s) Published by the Royal Society. All
rights reserved.
Drennov, O.B., Dynamic loading of solids with a negative slope of the melting curve
Technical Physics, 2013, 58 (9), pp. 1284-1287
Russian Federal Nuclear Center All-Russian Research Institute of Experimental Physics, Sarov
The results of experiments on shock-wave loading of materials distinguished by a negative slope of the
melting curve are reported. An anomalous situation is possible, when the material is melted by a shock
wave and then a fast transition to the solid phase takes place in the expansion wave. The newly formed
phase should be a nanostructural formation of the given element. Experiments confirmed the existence of
the transition from the liquid to the solid phase of the nanostructural modification.
A M Shikin1,6, A A Rybkina1, A S Korshunov 2,3, Yu B Kudasov 2,3, N V Frolova 2,3, A G Rybkin 1, D
Marchenko 1,4,5, J Sánchez-Barriga4, A Varykhalov4 and O Rader4, Induced Rashba splitting of
electronic states in monolayers of Au, Cu on a W(110) substrate
New Journal of Physics, 2013, 15, art. no. 095005
1
Saint Petersburg State University, Ulyanovskaya 1, Petrodvoretz, Saint Petersburg 198504, Russia
SarFTI, National Research Nuclear University MEPhI, Dukhova, 6, Sarov 607186, Russia
3
Russian Federal Nuclear Center—VNIIEF, Prospect Mira, 37, Sarov 607188, Russia
4
Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin,
Germany
2
5
Physikalische und Theoretische Chemie, Institut für Chemie und Biochemie, Freie Universität Berlin,
Takustraße 3, D-14195 Berlin, Germany
6
Author to whom any correspondence should be addressed
The paper sums up a theoretical and experimental investigation of the influence of the spin-orbit coupling
in W(110) on the spin structure of electronic states in deposited Au and Cu monolayers. Angle-resolved
photoemission spectroscopy reveals that in the case of monolayers of Au and Cu spin-orbit split bands are
formed in a surface-projected gap of W(110). Spin resolution shows that these states are spin polarized and
that, therefore, the spin-orbit splitting is of Rashba type. The states evolve from hybridization of W 5d, 6pderived states with the s, p states of the deposited metal. Interaction with Au and Cu shifts the original W
5d-derived states from the edges toward the center of the surface-projected gap. The size of the spin-orbit
splitting of the formed states does not correlate with the atomic number of the deposited metal and is even
higher for Cu than for Au. These states can be described as W-derived surface resonances modified by
hybridization with the p, d states of the adsorbed metal. Our electronic structure calculations performed in
the framework of the density functional theory correlate well with the experiment and demonstrate the
crucial role of the W top layer for the spin-orbit splitting. It is shown that the contributions of the spin-orbit
interaction from W and Au act in opposite directions which leads to a decrease of the resulting spin-orbit
splitting in the Au monolayer on W(110). For the Cu monolayer with lower spin-orbit interaction the
resulting spin splitting is higher and mainly determined by the W.
Pushkov, V.A., Yurlov, A.V., Podurets, A.M., Tsibikov, A.N., Tkachenko, M.I., Balandina, A.N., Effect
of preloading on the formation of adiabatic localized shear in copper
Combustion, Explosion and Shock Waves, 2013, 49 (5), pp. 620-624
Institute of Experimental Physics (VNIIEF)
This paper presents the results of a study of the formation of localized shear in M1 copper of two types: asreceived and after preloading by a quasi-entropic compression wave. The experiments were performed
with hat-shaped samples using the split Hopkinson bar method. For both types of copper, dynamic
compression diagrams were obtained at strain rates of 2100-2500 s-1. The copper structure was subjected
to metallographic analysis, and the effect of preliminary shock deformation on the dynamic mechanical
properties of the material was estimated. It is shown that preloaded higher-strength metals with a smaller
degree of strain hardening are more prone to the formation of adiabatic shear bands.
Babich, L.P.a, Kutsyk, I.M.a, Donsko, E.N.a, Dwyer, J.R.b, Analysis of the experiment on registration
of X-rays from the stepped leader of a cloud-to-ground lightning discharge
Journal of Geophysical Research A: Space Physics, 2013, 118 (5), pp. 2573-2582
a
Russian Federal Nuclear Center, VNIIEF, N. Novgorod Region, Sarov, Russian Federation
Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901,
United States
b
Using a Monte Carlo technique to simulate the transport of runaway electrons (REs) and X-rays in the
atmosphere and through attenuators covering detectors, we have modeled the results of experiments to
detect X-rays from triggered lightning and stepped leaders of a natural cloud-to-ground lightning. In the
model, bremsstrahlung of high-energy runaway electrons (REs) generated at the leader front is assumed to
be the origin of X-rays. Specific fluxes (per one RE) of photons and bremsstrahlung energy at the detectors
were calculated. The analysis was executed with monoenergetic and exponential initial energy distributions
of REs with different angular distributions. To reproduce the detected radiation energy of ~1-2 MeV, a
generation of ~1010-10 11 REs per flash is required in the case with the beam angular distribution of
monoenergetic REs with the energy in the range 1-10 MeV. The same result was obtained with the
exponential energy distribution of REs with the average energy 7 MeV, i.e., with the average energy in the
RE avalanche. The electric field amplifies the flux of the radiation energy, and the amplification becoming
stronger as the RE source approaches the ground. In the case with an isotropic angular distribution of REs
in the bottom hemisphere, with no electric field, (4-5) × 109 REs are required for reproducing ~1-2 MeV of
detected X-ray energy. In addition, fluxes of photons and fluxes of their energy at the detectors, energy
distributions of photons and their average energy were calculated. Key PointsThe x-ray emissions from
natural and triggered lightning are modeledModel results are compared with observations made at the
ICLRTNew estimations of the key properties of the runaway electrons are found.
Demidov, V.A., Sadunov, V.D., Kazakov, S.A., Boriskin, A.S.,Golosov, S.N., Vlasov, Y.V., Utenkov,
A.A., Antipov, M.V., Blinov, A.V., Autonomous magnetocumulative power supply
Technical Physics, 2013, 58 (8), pp. 1219-1223
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
Helical magnetocumulative generators (MCGs) fed from explosive piezo generators (EPGs) are the most
compact power supplies with an output energy of 1-10 kJ. EPGs are successfully coupled with MCGs in
the operation mode and in structural parameters; these generators are easy to operate and do not require
transformers or commutators. We report on the results of designing an autonomous small-size power
supply based on EPGs and MCGs. Owing to bidirectional impact loading of the piezoceramic block of an
EPG, the energy at the piezo generator output attains values of ∼25 J and is transferred to the helical MCG
with an initial inductance of ∼1000 μH. The power supply is constructed in the form of a monoblock with
a volume of ∼2 dm3 or in the form of two separate devices connected by a high-voltage cable
Bochkov, E.I., Babich, L.P., Kutsyk, I.M., Numerical simulation of narrow bipolar electromagnetic
pulses generated by thunderstorm discharges
Journal of Experimental and Theoretical Physics, 2013, 117 (1), pp. 177-184
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
Using the concept of avalanche relativistic runaway electrons (REs), we perform numerical simulations of
compact intracloud discharge (CID) as a generator of powerful natural electromagnetic pulses (EMPs) in
the HF-VHF range, called narrow bipolar pulses (NBPs). For several values of the field overvoltage and
altitude at which the discharge develops, the numbers of seed electrons initiating the avalanche are
evaluated, with which the calculated EMP characteristics are consistent with the measured NBP
parameters. We note shortcomings in the hypothesis assuming participation of cosmic ray air showers in
avalanche initiation. The discharge capable of generating NBPs produces REs in numbers close to those in
the source of terrestrial γ-ray flashes (TGFs), which can be an argument in favor of a unified NBP and
TGF source.
Babich, L.P., Bochkov, E.I., Kutsyk, I.M., Zalyalov, A.N., Erratum to "On Amplifications of
Photonuclear Neutron Flux in Thunderstorm Atmosphere and Possibility of Detecting Them"
(JETP Lett., (2013), 97, (291), 10.1134/S0021364013130018)
JETP Letters, 2013, 97 (8), pp. 505
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The reliability of communications reporting observations of neutron flux enhancements in thunderstorm
atmosphere is analyzed. The analysis is motivated by the fact that the employed gas-discharge counters on
the basis of reactions 3He(n, p)3H and 10B(n; 4He, γ)7Li detect not only neutrons but any penetrating
radiations. Photonuclear reactions are capable of accounting for the possible amplifications of neutron flux
in thunder-storm atmosphere since in correlation with thunderstorms γ-ray flashes were repeatedly
observed with spectra extending high above the threshold of photonuclear reactions in air. By numerical
simulations, it was demonstrated that γ-ray pulses detected in thunderstorm atmosphere are capable of
generating photonuclear neutrons in numbers sufficient to be detected even at sea level.
Denisov, E.A.a, Kompaniets, T.N.a , Yukhimchuk, A.A.b, Boitsov, I.E.b, Malkov, I.L.b Hydrogen and
helium in nickel and 12Kh18N10T steel
Technical Physics, 2013, 58 (6), pp. 779-786
а
Department of Physics, St. Petersburg State University, Ul'yanovskaya ul. 1, Petrodvorets, St.
Petersburg, 198504, Russian Federation
b
Russian Federal Nuclear Center, All-Russia Research Institute of Experimental Physics, pr. Mira 37,
Sarov, Nizhni Novgorod oblast, 607188, Russian Federation
A brief review of data for the influence of helium on the hydrogen sorption and mechanical properties of
nickel and 12Kh18N10T steel is presented. When in the metallic matrix, helium considerably deteriorates
the ductility of these metals. It is shown that 3He present in 12Kh18N10T steel generates high-energy
hydrogen traps
Babich, L.P., Bochkov, E.I., Kutsyk, I.M., Zalyalov, A.N., On amplifications of photonuclear neutron
flux in thunderstorm atmosphere and possibility of detecting them, JETP Letters, 2013, 97 (6), pp.
291-296
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The reliability of communications reporting observations of neutron flux enhancements in thunderstorm
atmosphere is analyzed. The analysis is motivated by the fact that the employed gas-discharge counters on
the basis of reactions 3He(n, p)3H and 10B(n; 4He, γ)7Li detect not only neutrons but any penetrating
radiations. Photonuclear reactions are capable of accounting for the possible amplifications of neutron flux
in thunder-storm atmosphere since in correlation with thunderstorms γ-ray flashes were repeatedly
observed with spectra extending high above the threshold of photonuclear reactions in air. By numerical
simulations, it was demonstrated that γ-ray pulses detected in thunderstorm atmosphere are capable of
generating photonuclear neutrons in numbers sufficient to be detected even at sea level.
Podurets, A.M., Tkachenko, M.I., Ignatova, O.N., Lebedev, A.I., Igonin, V.V., Raevskii, V.A. Dislocation
density in copper and tantalum subjected to shock compression depending on loading parameters
and original microstructure
Physics of Metals and Metallography, 2013, 114 (5), pp. 440-447
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The dislocation density ρ in copper and tantalum specimens with various grain size that remained after
high-strain-rate loading by shock and quasi-isentropic waves with amplitudes of 20-100 GPa has been
studied using X-ray diffraction analysis. The deformation rate was 106-10 9 s-1. It has been confirmed that
high-strain-rate loading generates a higher dislocation density in copper than does quasi-static deformation,
as well as that the shock-wave loading generates a higher dislocation density than quasi-isentropic loading.
In copper, a maximum of ρ has been found in the pressure range of P = 30-40 GPa, which corresponds to a
degree of deformation of 0.25-0.3, followed by a drop. This drop in ρ is explained by the partial annealing
of defects during adiabatic heating resulting from compression. An increase in ρ in copper with decreasing
specimen temperature has been noted. In tantalum, an increase in the shock wave pressure leads to a
monotonic increase in the dislocation density. No effect of heating on the annealing of defects in tantalum
has been found, even under the maximum pressure. As the average grain size increases, ρ increases in both
copper and tantalum.
Limonov, A.V., Perminov, A.V., Voevodin, S.V., Gorokhov, V.V., Kirzhaev, A.S., Buyanov, A.B.,
Karelin, V.I., Lashmanov, Y.N., Mustaikin, M.M., A low-frequency high-power arbitrary-shape
voltage pulse generator
Instruments and Experimental Techniques, 2013, 56 (3), pp. 283-286
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
A circuit diagram and design of the arbitrary-shape bipolar voltage pulse generator with amplitudes up to
800 V and a peak output on a matched load of 400 kW are described. The generator is based on car
rechargeable batteries and power insulated-gate bipolar transistors (IGBTs). Results of the experiments
aimed at producing high-power harmonic signals with frequencies of 50 Hz and 1 kHz are presented.
Dubinov, A.E., Sazonkin, M.A., Supernonlinear ion-acoustic waves in a dusty plasma
Physics of Wave Phenomena, 2013, 21 (2), pp. 118-128
Russian Federal Nuclear Center-All-Russian Research Institute of Experimental Physics, pr. Mira 37,
Sarov, Nizhny Novgorod oblast, 607188, Russian Federation
An exact solution is obtained for the equations that describe nonlinear ion-acoustic waves in a dusty
plasma. It is shown that the solution can be in the form of nonlinear periodic waves, solitons, and
supernonlinear waves whose trajectories envelope one or several separatrices in the phase portrait of the
wave. Profiles of physical quantities in the wave are constructed. The supernonlinear waves are shown to
be of two types, subsonic (type 1) and supersonic (type 2). Existence regions of supernonlinear waves of
both types and solitons are constructed in the plane of the problem parameters.
Shekunova, V.M.a , Sinyapkin, Yu.T.b, Didenkulova, I.I.a, Tsyganova, E.I.a, Aleksandrov, Yu.A.a,
Sinyapkin, D.Yu.c, Catalytic pyrolysis of light hydrocarbons in the presence of ultrafine particles
formed by electrically induced explosive dispersion of metal wires
Petroleum Chemistry, 2013, 53 (2), pp. 92-96
a
Research Institute of Chemistry, Nizhni Novgorod State University, Nizhni Novgorod, Russian Federation
b
All-Russia Research Institute of Experimental Physics (VNIIEF), Russian Federal Nuclear Center, Sarov,
Nizhni Novgorod oblast, Russian Federation
c
Research Laboratory of Plasma Processing NPK PLAZMATEK, Sarov, Nizhni Novgorod oblast, Russian
Federation
The catalytic pyrolysis of C1-C4 light hydrocarbons in a continuous tubular reactor in the presence of
ultrafine metal particles formed by electrical exploding of monometallic (Ag, Al, Cu, Fe, Ni, Ti, Pt, W,
Mo) and bimetallic (Mo, Cu; Fe, Al; W, Ni; W, Pt) wires has been studied. The study has been performed
in the temperature range of 500-850°C, a gas mixture flow rate of 50-100 mL/min, and a contact time of 510 s. The catalytic activities of ultrafine particles have been matched under comparable conditions, the
influence of the metal nature on the yield of ethylene and propylene has been examined, and sooting has
been evaluated. The best results for the basic parameters of the catalytic pyrolysis of C1-C4 hydrocarbons
(yield of ethylene and propylene, ethylene selectivity, and coking) have been shown by W, Fe, and Mo
ultrafine particles obtained by electrical explosion of respective wires.
Piskunov, V.N., Analytical solutions for coagulation and condensation kinetics of composite particles
Physica D: Nonlinear Phenomena, 2013, 249, pp. 38-45
Russian Federal Nuclear Center-VNIIEF, Mira 37, 607190, Sarov, Russian Federation
The processes of composite particles formation consisting of a mixture of different materials are essential
for many practical problems: for analysis of the consequences of accidental releases in atmosphere; for
simulation of precipitation formation in clouds; for description of multi-phase processes in chemical
reactors and industrial facilities. Computer codes developed for numerical simulation of these processes
require optimization of computational methods and verification of numerical programs. Kinetic equations
of composite particle formation are given in this work in a concise form (impurity integrated).
Coagulation, condensation and external sources associated with nucleation are taken into account.
Analytical solutions were obtained in a number of model cases. The general laws for fraction redistribution
of impurities were defined. The results can be applied to develop numerical algorithms considerably
reducing the simulation effort, as well as to verify the numerical programs for calculation of the formation
kinetics of composite particles in the problems of practical importance.
Trutnev, Y.A., Shagaliev, R.M., Evdokimov, V.V., Bochkov, A.I., Participation of V. S. Vladimirov in
work on the USSR atomic project: A significant milestone in the development of the foundations of
mathematical modeling of the processes of neutron physics
Theoretical and Mathematical Physics, 2013, 174 (2), pp. 173-177
Russian Federal Nuclear Center, All-Russian Scientific Research Institute for Experimental Physics,
Sarov, Nizhegorodskaya Oblast, Russian Federation
This paper is dedicated to the 90th anniversary of the birth of a leading Soviet and Russian scientist and a
member of the USSR Academy of Sciences: Academician Vasilii Sergeevich Vladimirov. Vladimirov, one
of the strongest contemporary mathematicians, worked from 1951 through 1955 at KB-11 (today, the
Russian Federal Nuclear Center - All-Russian Scientific Research Institute for Experimental Physics), the
"secret facility" where development of atomic weaponry was conducted. We present the main results of
Vladimirov's scientific activity connected with his work on the USSR atomic project.
Vyalykh, D.V., Dubinov, A.E., Zhdanov, V.S., L'vov, I.L., Sadovoi, S.A., Selemir, V.D., Observation of
nonlinear generation of higher RF harmonics in hollow-cathode discharge
Technical Physics Letters, 2013, 39 (2), pp. 217-219
All-Russia Research Institute of Experimental Physics, Russian Federal Nuclear Center, Sarov, Nizhni
Novgorod oblast, 607188, Russian Federation
Two variants of high-power RF oscillators based on hollow-cathode discharge have been studied. The
spectra of RF oscillations have been measured for two diameters and various lengths of the cathode cavity.
In both variants, the generation of high (second and third) harmonics has been observed, which is
apparently due to a nonlinear wave process in the discharge plasma. This phenomenon can be used for
carrier frequency doubling in RF generators of this type.
Kachalin, G.N., Pivkin, D.N., Polozov, A.A., Safronov, A.S., Khudikov, N.M., Focal spot analysis of
optical inhomogeneities appearing in the working medium of an iodine photodissociation laser with
flashlamp pumping
Technical Physics, 2013, 58 (1), pp. 114-121
All-Russian Research Institute of Experimental Physics, Russian Federal Nuclear Center, Sarov, Nizhni
Novgorod oblast, 607190, Russian Federation
We report on the results of experimental studies of optical inhomogeneities appearing in the working
medium of an iodine photodissociation laser operating in the inversion accumulation mode and in the freerunning mode. The dynamics of evolution of optical inhomogeneities in the free-running mode is studied
experimentally.
Chizhikov, S.I.a , Garanin, S.G.b, Goryachev, L.V.b, Molchanov, V.Ya.a, Romanov, V.V.b, Rukavishnikov,
N.N.b , Sokolovskii, S.V.b, Voronich, I.N.b, Yushkov, K.B.a, Acousto-optical adaptive correction of a
chirped laser pulse spectral profile in a Nd-phosphate glass regenerative amplifier
Laser Physics Letters, 2013, 10 (1), art. no. 015301
a
National University of Science and Technology MISIS, Acousto-Optical Research Center, Leninsky
prospect, 4, 119049 Moscow, Russian Federation
b
Russian Federal Nuclear Center - All Russian Research Institute of Experimental Physics, 37, Mir
Avenue, 607188 Sarov, Nizhniy Novgorod Region, Russian Federation
We present results of experimental research carried out with the help of an acousto-optical light dispersive
delay line (LDDL) on spectral correction of chirped laser pulses in a Nd-doped phosphate glass
regenerative amplifier (RA) characterized by high gain (G ≈ 4 × 107). The spectral resolution of the LDDL
was equal to 1.1 cm-1 at a diffraction efficiency greater than 80%. The use of the LDDL made it possible to
implement operating conditions of the RA under which the duration of the output chirped pulse did not
shorten in comparison with the duration of the input one, which meant that the width of the spectral
emission could be preserved.
Gordeev, D.G., Gudarenko, L.F., Kayakin, A.A., Kudel'kin, V.G., Equation of state model for metals
with ionization effectively taken into account. equation of state of tantalum, tungsten, aluminum,
and beryllium
Combustion, Explosion and Shock Waves, 2013, 49 (1), pp. 92-104
Institute of Experimental Physics, Russian Federal Nuclear Center (VNIIEF), Sarov, 607188, Russian
Federation
A model of a wide-range semi-empirical equation of state for metals is presented. The specific heat and
Gr̈uneisen coefficients of ions and electrons are functions of temperature and density. At low temperatures,
the heat capacity varies according to Debye theory. The removal of the degeneration of the electron gas
with increasing temperature is taken into account. The effect of ionization on the thermodynamic functions
is effectively taken into account. The equation of state allows the calculation of states in a two-phase
liquid-vapor region. This model was used to develop the equations of state for Ta, W, Al, and Be. For its
range of applicability, the equation of state contains a relatively small number of free parameters, most of
which have a physical meaning. Comparison of calculations of various isolines using equations of state
with experimental data and calculations based on other models show that the equations of state for Ta, W,
Al, and Be, describe most experimental data for these substances. At ultrahigh pressures and temperatures,
calculations using the equations of state are in good agreement with calculations using the Thomas-Fermi
model with corrections
Bazarov, M.Yu.a, Bazarov, Yu.B.bc, Golubev, M.B.b, Meshkov, E.E.c, The Whirlpool Splitting
Procedia IUTAM, 2013, 8, pp. 39-42
a
Gymnasium 2, Dukhova Str. 16, Sarov 607186, Russian Federation
Russian Federal Nuclear Center, Institute of Experimental Physics, Mira Str. 37, Sarov 607190, Russian
Federation
c
Sarov Physical and Technical Institute of NRNU MEPhI, Dukhova Str 6, Sarov 607186, Russian
Federation
b
An unusual phenomenon called "whirlpool splitting" by analogy with an axe splitting wood logs was
experimentally observed. In this experiment, a metal ruler, set vertically on the bottom of the aquarium on
the hole axis during flowing out of water has led to the separation of a whirlpool into two formed on both
sides of the rule and existed until the end of draining. The paper describes some results of experiments
based on the research of this phenomenon.
Yanilkin, Y.V.a , Goncharov, E.A.a , Kolobyanin, V.Y.a , Sadchikov, V.V.a, Kamm, J.R.b , Shashkov, M.J.c
, Rider, W.J.b, Multi-material pressure relaxation methods for Lagrangian hydrodynamics
Computers & Fluids, 16 August 2013, 83, pp. 137-143
a
All-Russian Research Institute of Experimental Physics, Sarov, Russian Federation
b
Sandia National Laboratories, Albuquerque, NM 87185, United States
c
Los Alamos National Laboratory, Los Alamos, NM 87545, United States
In Arbitrary Lagrangian-Eulerian (ALE) methods for hydrodynamics with several materials, multiplematerial Lagrangian cells invariably arise when the flow field is remapped onto a new mesh. One must
close the system of equations for multi-material cells; this, in effect, constitutes a model-either explicit or
implicit-for the sub-scale dynamics. We discuss several different multi-material closure model algorithms
for Lagrangian hydrodynamics under the assumption of a single velocity for 1D, multiple-material cells.
Russian researchers at the All-Russian Research Institute of Experimental Physics (VNIIEF) have
developed several models, which we describe in some detail; recent work by US researchers was
developed independent of the details of these models. This work contains a comparison of these different
approaches, which we believe is unique in the literature. We compare these methods on two standard test
problems and discuss the results.
Kudasov, Y.B.ab , Surdin, O.M.a, Korshunov, A.S.ab, Pavlov, V.N.ab, Frolova, N.V.b, Kuzin, R.S.b Lattice
dynamics and phase diagram of aluminum at high temperatures. Journal of Experimental and
Theoretical Physics, Volume 117, Issue 4, October 2013, Pages 664-671
a
Sarov State Institute of Physics and Technology, National Research Nuclear University MEPhI, Sarov
607188, Russian Federation
b
Russian Federal Nuclear Center-All-Russian Research Institute of Experimental Physics, pr. Mira 37,
Sarov 607188, Russian Federation
The dispersion of phonons in the fcc, hcp, and bcc phases of aluminum is calculated at ultrahigh pressures
by the method of small displacements in a supercell. The stability of the phonon subsystem is studied. The
thermodynamic characteristics are calculated in the quasi-harmonic approximation, and a phase diagram of
aluminum is plotted. As compared to the Debye model, the use of a phonon spectrum calculated in the
quasi-harmonic approximation significantly broadens the hcp phase field and strongly shifts the phase
boundary between the fcc and bcc phases. The normal isentrope is calculated at megabar pressures. It is
shown to intersect the fcc-hcp and hcp-bcc phase boundaries. The sound velocity along the normal
isentrope is calculated. It is shown to have a nonmonotonic character.
Dubinov A.E.ab , Maksimov, A.N.a , Pylayev, N.A.a , Selemir, V.D.ab Observation of ionization wave
refraction at a plane-parallel interface. IEEE Transactions on Plasma Science, Volume 41, Issue 3,
2013, Article number 6469245, Pages 447-449
a
Russian Federal Nuclear Center, All-Russian Scientific and Research Institute of Experimental Physics
(RFNC-VNIIEF), 607188 Sarov, Russian Federation
b
Sarov State Institute of Physics and Technology (SarFTI), National Research Nuclear University MEPhI,
607186 Sarov, Russian Federation
Photo images of ionization waves in a disk chamber are presented in this paper. The disk chamber has a
narrowing in the form of a ledge. Igniting a dc glow discharge, we observed for the first time refraction of
ionization wave beams at their passage of the ledge. The refraction is similar to one of light at a planeparallel plate. Analysis of the images confirmed the fulfillment of Snell's law for ionization waves.
Volkov V.A. , Volkov M.V., Garanin S.G. , Dolgopolov Y.V., Kopalkin A.V., Kulikov S.M., Starikov
F.A., Sukharev S.A., Tyutin S.V., Khokhlov S.V., Chaparin D.A. Dynamic phasing of multichannel cw
laser radiation by means of a stochastic gradient algorithm.
Quantum Electronics, Volume 43, Issue 9, 2013, Pages 852-856
Russian Federal Nuclear Center - All-Russian Research Institute of Experimental Physics, prosp. Mira 37,
607190 Sarov, Nizhni Novgorod region, Russian Federation
The phasing of a multichannel laser beam by means of an iterative stochastic parallel gradient (SPG)
algorithm has been numerically and experimentally investigated. The operation of the SPG algorithm is
simulated, the acceptable range of amplitudes of probe phase shifts is found, and the algorithm parameters
at which the desired Strehl number can be obtained with a minimum number of iterations are determined.
An experimental bench with phase modulators based on lithium niobate, which are controlled by a
multichannel electronic unit with a real-time microcontroller, has been designed. Phasing of 16 cw laser
beams at a system response bandwidth of 3.7 kHz and phase thermal distortions in a frequency band of
about 10 Hz is experimentally demonstrated. The experimental data are in complete agreement with the
calculation results.
Urlin V.D. Equations of state and phase diagrams of hydrogen isotopes.
Journal of Experimental and Theoretical Physics, Volume 117, Issue 5, November 2013, Pages 833-845
Russian Federal Nuclear Center All, Russia Research Institute of Experimental Physics, Sarov,
Nizhegorodskaya oblast 607188, Russian Federation
A new form of the semiempirical equation of state proposed for the liquid phase of hydrogen isotopes is
based on the assumption that its structure is formed by cells some of which contain hydrogen molecules
and others contain hydrogen atoms. The values of parameters in the equations of state of the solid
(molecular and atomic) phases as well as of the liquid phase of hydrogen isotopes (protium and deuterium)
are determined. Phase diagrams, shock adiabats, isentropes, isotherms, and the electrical conductivity of
compressed hydrogen are calculated. Comparison of the results of calculations with available experimental
data in a wide pressure range demonstrates satisfactory coincidence.
Nevmerzhitskiy N.V. Some peculiarities of turbulent mixing growth and perturbations at
hydrodynamic instabilities.
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences,
Volume 371, Issue 2003, 28 November 2013, Article number 20120291
Russian Federal Nuclear Center
The author presents a review of some experimental works devoted to the research of evolution of largescale perturbations and turbulent mixing (TM) in liquid and gaseous media during the growth of
hydrodynamic instabilities. In particular, it is shown that growth of perturbations and TM in gases is
sensitive to the Mach number of shock wave; character of gas front penetration into liquid is not changed
as the Reynolds number of flow increases from 5 × 105 to 107; and change of the Atwood number sign
from positive to negative causes stopping of gas front penetration into liquid, but mixing zone width is
expanded under inertia.
Kantsyrev A.V.a, Golubev A.A.a, Turtikov V.I.a, Bogdanov A.V.a, Sharkov B.Y.a, Demidov V.S.a,
Skachkov Vl.S.a, Markov N.V.a, Mintsev V.B.b, Fortov V.E.b, Kolesnikov S.A.b, Nikolaev D.N.b, Shilkin
N.S.b, Ternovoy V.Y.b, Utkin A.V.b, Yuriev D.S.b, Burtsev V.V.c, Zavialov N.V.c, Mikhailov A.L.c,
Rudnev A.V.c, Tatsenko M.V.c, Zhernokletov M.V.c, Kartanov S.A.c ITEP proton microscopy facility.
Digest of Technical Papers-IEEE International Pulsed Power Conference 2013, Article number 6627498
2013 19th IEEE Pulsed Power Conference, PPC 2013; San Francisco, CA; United States; 16 June 2013
through 21 June 2013; Code 101034
a
Institute for Theoretical and Experimental Physics, Moscow 117218, Russian Federation
b
Institute of Problems of Chemical Physics RAS, Chernogolovka 142432, Russian Federation
c
Russian Federal Nuclear Center, All-Russian Research Institute of Experimental Physics, Sarov 607188,
Russian Federation
The proton radiography facility which uses magnetic optics (proton microscope PUMA [7]) was developed
at TWAC-ITEP accelerator [1,2,6]. PUMA proton microscopy facility was specially designed for studies
in the field of high energy density physics, including the research of equations of state and phase
transitions of matter at extreme conditions, shockwave and detonation physics, hydrodynamics of high
energy density flows, and dynamic material strength and damage studies [10,11]. Proton microscope
PUMA allows the measurement of density distribution within static and dynamic objects by using a proton
beam with energy of 800MeV. Proton-radiographic image of the object is formed in the plane of the
detector with magnification k=4. An image of the object is formed using a magneto-optical system
consisting of four quadrupole lenses on permanent magnets (PMQ). PUMA facility is designed for the
measurement of objects with areal density of 20 g/cm2 and field of view of 20 mm. For the facility, the
spatial resolution is from 60 microns to 115 microns for objects with areal density from 0.46 g/cm2 to 17
g/cm2, respectively. Research was also performed on nondestructive testing of static objects (including
tomographic methods) and radiobiological studies.
Bondarenko S.V.a , Dolgoleva G.V.b , Novikova E.A.a Numerical analysis of experiments on the
generation of shock waves in aluminium under indirect (X-ray) action on the Iskra-5 facility.
Quantum Electronics, Volume 43, Issue 7, 2013, Pages 630-637
a
Russian Federal Nuclear Centre, All-Russian Research Institute of Experimental Physics, prosp. Mira 37,
607190 Sarov, Nizhnii Novgorod region, Russian Federation
b
M.V. Keldysh Institute for Applied Mathematics, Russian Academy of Sciences, Miusskaya pl. 4, 125047
Moscow, Russian Federation
The dynamics of laser and X-ray radiation fields in experiments with cylindrical converter boxes
(illuminators), which had earlier been carried out on the Iskra-5 laser facility (the second harmonic of
iodine laser radiation, λ = 0.66 μm) was investigated in a sector approximation using the SND-LIRA
numerical technique. In these experiments, the X-ray radiation temperature in the box was determined by
measuring the velocity of the shock wave generated in the sample under investigation, which was located
at the end of the cylindrical illuminator. Through simulations were made using the SND-LIRA code, which
took into account the absorption of laser driver radiation at the box walls, the production of quasithermal
radiation, as well as the formation and propagation of the shock wave in the sample under investigation.
An analysis of the experiments permits determining the electron thermal flux limiter f: for f = 0.03 it is
possible to match the experimental scaling data for X-ray in-box radiation temperature to the data of our
simulations. The shock velocities obtained from the simulations are also consistent with experimental data.
In particular, in the experiment with six laser beams (and a laser energy E L = 1380 J introduced into the
box) the velocity of the shock front (determined from the position of a laser mark) after passage through a
50-μm thick base aluminium layer was equal to 35±1.6 km s-1, and in simulations to 36 km s-1. In the
experiment with four laser beams (for EL = 850 J) the shock velocity (measured from the difference of
transit times through the base aluminium layer and an additional thin aluminium platelet) was equal to
30±3.6 km s-1, and in simulations to 30 km s-1.
Ilkaev R.I., Major stages of the atomic project.
Physics-Uspekhi, Volume 56, Issue 5, 2013, Pages 502-509
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The implementation of the Soviet Atomic Project was an issue of the greatest State priority. Its solution
was based on mobilizing the best personnel and cadres in the country, including specialists of the highest
qualification, scientists in academic research institutes and industrial institutions, and organizers of the
defense industry in the USSR who identified candidatures and trained research and managerial leaders at
every level of the Atomic Project. The Atomic Project laid the foundation of the security of the country in
the second half of the 20th century by eliminating the atomic and thermonuclear monopoly of the USA.
The main stages of the Soviet Atomic Project the period from 1943-1949 when the Laboratory No. 2, of
the research, technological, and industrial infrastructure of the nuclear industry was created under I V
Kurchatov's guidance.
Spirov G.M.a ,Bochkaryev A.V.b ,Dubinov A.E.b ,Loboda, A.V.b , Zuimatch E.A.b , Bespalova A.N.c Effect of
plasma and UV radiation of multigap sliding discharge in air on bacteria.
IEEE Transactions on Plasma Science, Volume 41, Issue 8, 2013, Article number 6558866, Pages 23812386
a
Scientific and Technical Center of High-Energy Density Physics and Directed Radiation Fluxes, Russian
Federal Nuclear Center, All-Russia Scientific and Research Institute of Experimental Physics, Sarov
607188, Russian Federation
b
Russian Federal Nuclear Center, All-Russia Scientific and Research Institute of Experimental Physics,
Sarov 607188, Russian Federation
c
Center of Hygiene and Epidemiology, Sarov 607188, Russian Federation
The device generating pulsed-periodic multigap sliding discharges in air was used to study the impact of
plasma and UV radiation on bacterial test objects, which were prepopulated with bacteria Escherichia coli
(Ec) and Staphylococcus aureus (Sa). Bactericidal effect was revealed, which varied depending on period
of impact, distance, and exposure time. It is found that Sa bacteria were less resistant to plasma and UV
treatments than Ec bacteria.
Dubinov A.E., Mytareva L.A., Saikov S.K., Selemir V.D., Optimal ion beam current in electromagnetic
isotope separation facilities.
Atomic Energy, Volume 114, Issue 3, July 2013, Pages 207-208
Russian Federal Nuclear Center, All-Russia Scientific and Research Institute of Experimental Physics,
Sarov 607188, Russian Federation
To generate uranium ion beam with high current and high brightness to fill up the heavy ion synchrotron
SIS to its space charge limit, the behavior of the uranium ion beam in the extraction system and the
postacceleration system for a high current metal vapor vacuum arc ion source has been investigated using
the KOBRA3-INP code. The beam trajectory and space charge map in the extraction system as well as
space profiles and the emittance diagrams of the ion beam along the beam line are presented. The
influences of degree of the space charge compensation on the characteristics of the extracted ion beam are
discussed. The results show that the ion beam has to be space charge compensated from the screening
electrode to the entrance of the acceleration gap; otherwise the transport would not be possible. Simulation
also quantitatively supports the experimental results under the assumption of the full space charge
compensation in the drift sections.
Garanin S.G., Starikov F.A., Shnyagin R.A. Applying the stochastic parallel gradient algorithm in the
auto alignment problem for the amplifier channel of the UFL-2M facility.
Optics and Spectroscopy, Volume 114, Issue 6, June 2013, Pages 851-858
All-Russian Research Institute of Experimental Physics, Institute of Laser Physics Research, Russian
Federal Nuclear Center, Sarov, Nizhni Novgorod oblast 607200, Russian Federation
The procedure of automatic alignment of the four-pass amplifier channel of a UFL-2M facility has been
simulated numerically in the presence of aberrations in the optical path. The alignment procedure is based
on the "marker" or "reference" method. The control elements are directed by the stochastic parallel
gradient algorithm. The order of executing the automatic alignment is determined. The numerical
simulation shows the possibility of positioning the beam at the exit from the channel with an accuracy of
1% of the pinhole size in the far field and of 0.1% of the beam aperture size in the near field. It was
established that the centering accuracy of the alignment beam in inner pinholes in the presence of optical
inhomogeneities in the amplifier channel can be worse than at the exit of the channel. The possibility of
symmetrizing the picture of far-field markers has been considered in the case where the position of the
optical axis of the channel is unknown.
Zavyalov N.V., Maslov V.V., Rumyantsev V.G. , Drozdov I.Y., Ershov D.A., Korkin D.S., Molodtsev
D.A., Smerdov V.I., Falin A.P., Yukhimchuk A.A., A source with a 1013 DT neutron yield on the basis
of a spherical plasma focus chamber.
Plasma Physics Reports, Volume 39, Issue 3, 2013, Pages 243-247
Russian Federal Nuclear Center, All-Russian Scientific Research Institute of Experimental Physics, ul.
Mira 37, Sarov, 607188, Russian Federation
Results from preliminary experimental research of neutron emission generated by a spherical plasma focus
chamber filled with an equal-component deuterium-tritium mixture are presented. At a maximum current
amplitude in the discharge chamber of ~1.5 MA, neutron pulses with a full width at half-maximum of 7580 ns and an integral yield of ~1.3 × 1013 DT neutrons have been recorded.
Popov N.N., Lar'kin V.F., Presnyakov D.V., Aushev A.A., Sysoeva T.I., Kostyleva A.A., Suvorova E.B.
Investigation of thermomechanical characteristics of shape-memory alloys of the Ti-Ni-Nb system
and of the effect of heat treatment on them.
Physics of Metals and Metallography, Volume 114, Issue 4, April 2013, Pages 348-357
Russian Federal Nuclear Center, All-Russian Research Institute of Experimental Physics, pr. Mira 37,
Sarov, Nizhny Novgorod oblast 607188, Russian Federation
The properties of shape-memory titanium nickelide-based alloys alloyed with niobium have been
investigated for use in developing progressive technology for thermomechanical joints of pipelines and
cylindrical elements of constructions of couplings fabricated from these alloys. In the process of the
investigations, the elemental and phase compositions of alloys of the Ti-Ni-Nb system in the cast and
pressed states have been determined; their microstructure, kinetics, and temperatures of phase
transformations have been studied; the main mechanical characteristics have been determined; the
thermomechanical characteristics and the effect of different types and regimes of heat treatment on them
have been investigated. The results of these investigations confirmed the suitability of the alloys for use in
thermomechanical joints of pipelines; couplings can be stored at temperatures of up to 40 C without a loss
of deformation induced in them. By changing certain mechanical and thermomechanical characteristics of
alloys of the Ti-Ni-Nb system in the cast and pressed states using different types and regimes of heat
treatment, the field of employment of these materials can be expanded.
Chuvil'deev, V.N.a, Nokhrin, A.V.a , Baranov, G.V.b, Moskvicheva, A.V.a, Boldin, M.S.a, Kotkov, D.N.a,
Sakharov, N.V.a, Blagoveshchenskii, Y.V.c, Shotin, S.V.a, Melekhin, N.V.a, Belov, V.Y.b Study of the
structure and mechanical properties of nano- and ultradispersed mechanically activated heavy
tungsten alloys.
Nanotechnologies in Russia, Volume 8, Issue 1-2, 2013, Pages 108-121
a
Scientific-Research Physical-Technical Institute, Lobachevsky State University, Nizhni Novgorod, pr.
Gagarina 23/3, Nizhni Novgorod, 603950, Russian Federation
b
Russian Federal Nuclear Center, Institute of Experimental Physics, pr. Mira 37, Sarov, Nizhni Novgorod
oblast, 607188, Russian Federation
c
Baikov Institute of Metallurgy and Material Sciences, Russian Academy of Sciences, Leninskii pr. 49,
Moscow, 119991, Russian Federation
Mechanisms of sintering and the structure and mechanical properties of nano- and ultradispersed W-Ni-Fe
(WNF) and W-Ni-Fe-Co (WNFC) heavy tungsten alloys are investigated. The effect of tungsten particle
sizes on the optimal sintering temperature is studied. The size of particles has been changed by the
mechanical activation (MA) of the source W-Ni-Fe coarse-grained (CG) charge and by adding
ultradispersed particles obtained using plasmochemical synthesis. Nanodispersed powders and
ultradispersed powders (UDPs) have been sintered using the techniques of free sintering and pulse plasma
sintering (PPS). It has been revealed that the dependence of the alloy density on heating temperature is
nonmonotonic, with the maximum corresponding to the optimum sintering temperature. It has been shown
that an increase in the time of MA and acceleration of grinding bodies in the process of MA accompanied
by a decrease in the size of alloy particles and formation of nonequilibrium solid solutions lead to a
reduction in the optimal sintering temperature. It has been shown that, using planetary high-energy milling
methods and high-rate spark plasma sintering, it is possible to obtain ultrastrong tungsten alloys whose
mechanical properties (macroelasticity stress and yield stress) substantially exceed analogous properties of
commercial alloys
Dubinov, A.E., L'Vov, I.L., Sadovoy, S.A., Senilov, L.A., Vyalykh, D.V. Generalized Leonardo da Vinci
rule for the discharges, sliding on electrolyte surfaces.
IEEE Transactions on Plasma Science, Volume 41, Issue 2, 2013, Article number 6408395, Pages 380-383
Russian Federal Nuclear Center, All-Russian Research Institute of Experimental Physics, Sarov 607188,
Russian Federation
Photo images of branching discharges and sliding on electrolyte surfaces are presented. Based on the
analysis of these images, the diametrical index for the generalized Leonardo da Vinci rule is calculated. It
turns out that the value of the diametric index is close to 0.7. We attempt to explain such a low index value.
Belonogov, A.N., Dubinov, A.E., Maksimov, A.N., Selemir, V.D. The effects of wave optics as they are
observed in ionization waves in plasma.
IEEE Transactions on Plasma Science, Volume 41, Issue 1, 2013, Article number 6387315, Pages 36-42
Russian Federal Nuclear Center - All-Russian Scientific and Research, Institute of Experimental Physics,
Sarov 607188, Russian Federation
A wire-discharge chamber containing a hollow cathode was designed and tested at reduced pressure.
Immobile ionization waves in the form of circular strata and 2-D wave beams were obtained from the
mixture of air and ethanol vapor. Wave images in polygonal and spiral forms were recorded. Patterns of
ionization waves having topologically nontrivial forms featuring separatrix were found. Diffraction effects
of wave optics associated with the scattering of ionization waves on obstacles and slots (the Fraunhofer
diffraction) were observed for the first time
Sosnin, E.A.ab , Panarin, V.A.a, Pikulev, A.A.c, Tarasenko, V.F.a Theoretical and experimental study of
the acoustic spectrum of a DBD-driven planar KrCl excilamp.
European Physical Journal D, Volume 67, Issue 1, January 2013, Article number 9
a
Institute of High Current Electronics SB RAS, 634055 Tomsk, Russian Federation
b
Tomsk State University, 634055 Tomsk, Russian Federation
c
All-Russia Scientific Research Institute Experimental Physics - Russian Federal Nuclear Centre, 607188
Sarov, Russian Federation
Experiments and theoretical simulation were performed to study the acoustic characteristics of a planar
KrCl excilamp driven by a dielectric barrier discharge (DBD) with a mixture ratio of Kr:Cl2 = 400:1 at a
pressure of 20 kPa. The acoustic spectrum of the excilamp bulb was measured and resonances at 4.96,
5.36, 9.92, 10.8, and 21.6 kHz were detected. The natural frequency of the bulb walls and the acoustic
frequency of the gas were calculated. The acoustic energy of the gas was determined depending on the
vibration frequency of the bulb walls. Comparison of the experimental and simulation data shows that in
the frequency range >10 kHz, acoustic peaks occur at natural frequencies of the gas in the excilamp bulb.
Vasyukov, V.A.a, Glybin, A.M.a, Duday, P.V.a, Dudin, V.I.a, Zimenkov, A.A.a, Ivanov, V.A.a,
Ivanovskiy, A.V.a, Kraev, A.I.a, Kuzyaev, A.I.a, Nadezhin, S.S.a, Petrukhin, A.A.a, Skobelev, A.N.a,
Tyupanova, O.A.a, Atchison, W.L.b, Griego, J.R.b, Holtkamp, D.B.b, Kaul, A.M.b, Reinovsky, R.E.b,
Rodriguez, G.b, (...), Payton, J.R.b, Westley, D.T.b, Rheology studies of aluminum with the use of
explosive magnetic generators
Doklady Physics, Volume 58, Issue 1, January 2013, Pages 20-23
a
Russian Federal Nuclear Center - All-Russia Research Institute of Experimental Physics, Sarov 607190,
Russian Federation
b
Los Alamos National Laboratory, New Mexico 87545, United States
A study was conducted to perform rheology investigations of aluminum with the use of explosive magnetic
generators. The hollow cylindrical aluminum samples were loaded by the impact of the cylindrical liners
imploded by the magnetic field generated by an explosive magnetic pulsed current source. The targets
were placed in the casing of two cylindrical momentum traps to eliminate the effect of the side unloading
along the symmetry axis of the targets. The explosive magnetic source included a HEMG, an explosive
current opening switch (OS), an explosive current interrupter (CI), and a coaxial transmission line (TL)
supplying the current to the liner. The use of magnetic field pressure to drive the liners-impactors in the
experiments ensured symmetry and uniformity of the impactor motion, precise control of impact velocity,
and high precision of the target loading. The use of short, precisely shaped current pulses also ensured that
a single impact of the liner against the target resulted in loading the target with one shock wave.
Budnikov, D., etc., Multiplicity dependence of the average transverse momentum in pp, p-Pb, and
Pb-Pb collisions at the LHC
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2013, 727 (4-5), pp.
371-380
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The average transverse momentum <p_T> versus the charged-particle multiplicity, N_ch was measured in
p-Pb collisions at a collision energy per nucleon-nucleon pair sqrt(s_NN) = 5.02 TeV and in pp collisions
at collision energies of sqrt(s) = 0.9, 2.76, and 7 Tev in the kinematic range 0.15 < p_T < 10.0 Gev/c and
|eta| < 0.3 with the ALICE apparatus at the LHC. These data are compared to results in Pb-Pb collisions at
sqrt(s_NN) = 2.76 Tev at similar charged-particle multiplicities. In pp and p-Pb collisions, a strong
increase of <p_T> with N_ch is observed, which is much stronger than that measured in Pb-Pb collisions.
For pp collisions, this could be attributed, within a model of hadronizing strings, to multiple-parton
interactions and to a final-state color reconnection mechanism. The data in p-Pb and Pb-Pb collisions
cannot be described by an incoherent superposition of nucleon-nucleon collisions and pose a challenge to
most of the event generators.
Budnikov, D., etc., Directed flow of charged particles at midrapidity relative to the spectator plane in
Pb-Pb collisions at √sNN=2.76 TeV
Physical Review Letters, 2013, 111 (23), art. no. 232302
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The directed flow of charged particles at midrapidity is measured in Pb-Pb collisions at s NN − − − √
=2.76 TeV relative to the collision symmetry plane defined by the spectator nucleons. A negative slope of
the rapidity-odd directed flow component with approximately 3 times smaller magnitude than found at the
highest RHIC energy is observed. This suggests a smaller longitudinal tilt of the initial system and
disfavors the strong fireball rotation predicted for the LHC energies. The rapidity-even directed flow
component is measured for the first time with spectators and found to be independent of pseudorapidity
with a sign change at transverse momenta p T between 1.2 and 1.7 GeV/c . Combined with the observation
of a vanishing rapidity-even p T shift along the spectator deflection this is strong evidence for dipolelike
initial density fluctuations in the overlap zone of the nuclei. Similar trends in the rapidity-even directed
flow and the estimate from two-particle correlations at midrapidity, which is larger by about a factor of 40,
indicate a weak correlation between fluctuating participant and spectator symmetry planes. These
observations open new possibilities for investigation of the initial conditions in heavy-ion collisions with
spectator nucleons.
Budnikov, D., etc., Charmonium and e+e- pair photoproduction at mid-rapidity in ultra-peripheral
Pb-Pb collisions at √sNN = 2.76 Tev
European Physical Journal C, 2013, 73 (11), pp. 1-18
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The ALICE Collaboration at the LHC has measured the j/psi and psi'photoproduction at mid-rapidity in
ultra-peripheral Pb-Pb collisions atsqrt(sNN) = 2.76 TeV. The charmonium is identified via its leptonic
decay forevents where the hadronic activity is required to be minimal. The analysis isbased on an event
sample corresponding to an integrated luminosity of about 23{mu}b^{-1}. The cross section for coherent
and incoherent j/psi production inthe rapidity interval -0.9 < y < 0.9, are d{sigma}_{J/{psi}}^{coh}/dy
=2.38^{+0.34}_{-0.24}(sta+sys) mb and d{sigma}_{J/{psi}}^{inc}/dy =0.98^{+0.19}_{-0.17}(sta+sys)
mb, respectively. The results are compared totheoretical models for j/{psi} production and the coherent
cross section isfound to be in good agreement with those models which include nuclear gluonshadowing
consistent with EPS09 parametrization. In addition the cross sectionfor the process {gamma}{gamma} ->
e+e- has been measured and found to be inagreement with the STARLIGHT Monte Carlo predictions.
Budnikov, D., etc., KS0 and Λ production in Pb-Pb collisions at √s NN=2.76 TeV
Physical Review Letters, 2013, 111 (22), art. no. 222301
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The ALICE measurement of KS0 and Λ production at midrapidity in Pb-Pb collisions at √sNN=2.76 TeV
is presented. The transverse momentum (pT) spectra are shown for several collision centrality intervals and
in the pT range from 0.4 GeV/c (0.6 GeV/c for Λ) to 12 GeV/c. The pT dependence of the Λ/KS0 ratios
exhibits maxima in the vicinity of 3 GeV/c, and the positions of the maxima shift towards higher pT with
increasing collision centrality. The magnitude of these maxima increases by almost a factor of three
between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate pT is not
observed in pp interactions at √s=0.9 TeV and at √s=7 TeV. Qualitatively, the baryon enhancement in
heavy-ion collisions is expected from radial flow. However, the measured pT spectra above 2 GeV/c
progressively decouple from hydrodynamical-model calculations. For higher values of pT, models that
incorporate the influence of the medium on the fragmentation and hadronization processes describe
qualitatively the p T dependence of the Λ/KS0 ratio.
Budnikov, D., etc., J/ψ elliptic flow in Pb-Pb Collisions at √sNN=2.76 TeV
Physical Review Letters, 2013, 111 (16), art. no. 162301
Russian Federal Nuclear Center (VNIIEF), Sarov, Russian Federation
We report on the first measurement of inclusive J/ψ elliptic flow v2 in heavy-ion collisions at the LHC.
The measurement is performed with the ALICE detector in Pb-Pb collisions at √sNN=2.76 TeV in the
rapidity range 2.5<y<4.0. The dependence of the J/ψ v2 on the collision centrality and on the J/ψ
transverse momentum is studied in the range 0≤pT<10 GeV/c. For semicentral Pb-Pb collisions at
√sNN=2.76 TeV, an indication of nonzero v2 is observed with a largest measured value of
v2=0.116±0.046(stat) ±0.029(syst) for J/ψ in the transverse momentum range 2≤p T<4 GeV/c. The elliptic
flow measurement complements the previously reported ALICE results on the inclusive J/ψ nuclear
modification factor and favors the scenario of a significant fraction of J/ψ production from charm quarks in
a deconfined partonic phase.
Budnikov, D., etc., Centrality determination of Pb-Pb collisions at √sNN=2.76 TeV with ALICE
Physical Review C - Nuclear Physics, 2013, 88 (4), art. no. 044909
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
This publication describes the methods used to measure the centrality of inelastic Pb-Pb collisions at a
center-of-mass energy of 2.76 TeV per colliding nucleon pair with ALICE. The centrality is a key
parameter in the study of the properties of QCD matter at extreme temperature and energy density, because
it is directly related to the initial overlap region of the colliding nuclei. Geometrical properties of the
collision, such as the number of participating nucleons and the number of binary nucleon-nucleon
collisions, are deduced from a Glauber model with a sharp impact parameter selection and shown to be
consistent with those extracted from the data. The centrality determination provides a tool to compare
ALICE measurements with those of other experiments and with theoretical calculations.
Budnikov, D., etc., Centrality dependence of π, K, and p production in Pb-Pb collisions at √sNN=2.76
TeV
Physical Review C - Nuclear Physics, 2013, 88 (4), art. no. 044910
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
In this paper measurements are presented of π±, K ±, p, and p̄ production at midrapidity (|y|<0.5), in Pb-Pb
collisions at √sNN=2.76 TeV as a function of centrality. The measurement covers the transversemomentum (pT) range from 100, 200, and 300 MeV/c up to 3, 3, and 4.6 GeV/c for π, K, and p,
respectively. The measured pT distributions and yields are compared to expectations based on
hydrodynamic, thermal and recombination models. The spectral shapes of central collisions show a
stronger radial flow than measured at lower energies, which can be described in hydrodynamic models. In
peripheral collisions, the pT distributions are not well reproduced by hydrodynamic models. Ratios of
integrated particle yields are found to be nearly independent of centrality. The yield of protons normalized
to pions is a factor ∼1.5 lower than the expectation from thermal models.
Budnikov, D., etc., Multiplicity dependence of two-particle azimuthal correlations in pp collisions at
the LHC
Journal of High Energy Physics, 2013, 2013 (9), art. no. 049
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
We present the measurements of particle pair yields per trigger particle obtained from di-hadron azimuthal
correlations in pp collisions at = 0.9, 2.76, and 7 TeV recorded with the ALICE detector. The yields are
studied as a function of the charged particle multiplicity. Taken together with the single particle yields the
pair yields provide information about parton fragmentation at low transverse momenta, as well as on the
contribution of multiple parton interactions to particle production. Data are compared to calculations using
the PYTHIA6, PYTHIA8, and PHOJET event generators.
Budnikov, D., etc., Performance of the ALICE VZERO system
Journal of Instrumentation, 2013, 8 (10), art. no. P10016
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
ALICE is an LHC experiment devoted to the study of strongly interacting matter in proton-proton, protonnucleus and nucleus-nucleus collisions at ultra-relativistic energies. The ALICE VZERO system, made of
two scintillator arrays at asymmetric positions, one on each side of the interaction point, plays a central
role in ALICE. In addition to its core function as a trigger source, the VZERO system is used to monitor
LHC beam conditions, to reject beam-induced backgrounds and to measure basic physics quantities such
as luminosity, particle multiplicity, centrality and event plane direction in nucleus-nucleus collisions. After
describing the VZERO system, this publication presents its performance over more than four years of
operation at the LHC.
Budnikov, D., etc., Centrality dependence of the pseudorapidity density distribution for charged
particles in Pb-Pb collisions at √sNN=2.76TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2013, 726 (4-5), pp.
610-622
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
We present the first wide-range measurement of the charged-particle pseudorapidity density distribution,
for different centralities (the 0-5%, 5-10%, 10-20%, and 20-30% most central events) in Pb-Pb collisions at
sNN=2.76TeV at the LHC. The measurement is performed using the full coverage of the ALICE detectors,
-5.0<η<5.5, and employing a special analysis technique based on collisions arising from LHC 'satellite'
bunches. We present the pseudorapidity density as a function of the number of participating nucleons as
well as an extrapolation to the total number of produced charged particles (Nch=17165±772 for the 0-5%
most central collisions). From the measured dNch/dη distribution we derive the rapidity density
distribution, dNch/dy, under simple assumptions. The rapidity density distribution is found to be
significantly wider than the predictions of the Landau model. We assess the validity of longitudinal scaling
by comparing to lower energy results from RHIC. Finally the mechanisms of the underlying particle
production are discussed based on a comparison with various theoretical models
Budnikov, D., etc., D meson elliptic flow in noncentral Pb-Pb collisions at √s NN=2.76 TeV
Physical Review Letters, 2013, 111 (10), art. no. 102301
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
Azimuthally anisotropic distributions of D0, D+, and D *+ mesons were studied in the central rapidity
region (|y|<0.8) in Pb-Pb collisions at a center-of-mass energy √s NN=2.76 TeV per nucleon-nucleon
collision, with the ALICE detector at the LHC. The second Fourier coefficient v2 (commonly denoted
elliptic flow) was measured in the centrality class 30%-50% as a function of the D meson transverse
momentum pT, in the range 2-16 GeV/c. The measured v2 of D mesons is comparable in magnitude to that
of light-flavor hadrons. It is positive in the range 2<pT<6 GeV/c with 5.7σ significance, based on the
combination of statistical and systematic uncertainties. © 2013 CERN, for the LHCb Collaboration
Published by the American Physical Society under the terms of the http://creativecommons.
org/licenses/by/3.0/ Creative Commons Attribution 3.0 License. Further distribution of this work must
maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
Budnikov, D., etc., Long-range angular correlations of π, K and p in p-Pb collisions at sNN=5.02 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2013, 726 (1-3), pp.
164-177
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
Angular correlations between unidentified charged trigger particles and various species of charged
associated particles (unidentified particles, pions, kaons, protons and antiprotons) are measured by the
ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV in the
transverse-momentum range 0.3<pT<4 GeV/c. The correlations expressed as associated yield per trigger
particle are obtained in the pseudorapidity range |ηlab|<0.8. Fourier coefficients are extracted from the
long-range correlations projected onto the azimuthal angle difference and studied as a function of pT and
in intervals of event multiplicity. In high-multiplicity events, the second-order coefficient for protons, v2p,
is observed to be smaller than that for pions, v2π, up to about pT=2 GeV/c. To reduce correlations due to
jets, the per-trigger yield measured in low-multiplicity events is subtracted from that in high-multiplicity
events. A two-ridge structure is obtained for all particle species. The Fourier decomposition of this
structure shows that the second-order coefficients for pions and kaons are similar. The v2p is found to be
smaller at low pT and larger at higher pT than v2π, with a crossing occurring at about 2 GeV/c. This is
qualitatively similar to the elliptic-flow pattern observed in heavy-ion collisions. A mass ordering effect at
low transverse momenta is consistent with expectations from hydrodynamic model calculations assuming a
collectively expanding system.
Budnikov, D., etc., Mid-rapidity anti-baryon to baryon ratios in pp collisions at √s = 0.9, 2.76 and 7
TeV measured by ALICE
European Physical Journal C, 2013, 73 (7), pp. 1-22
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The ratios of yields of anti-baryons to baryons probes the mechanisms of baryon-number transport. Results
for p̄/p, Λ/Λ, Ξ+/Ξ- and Ω+/Ω- in pp collisions at √s = 0.9, 2.76 and 7 TeV, measured with the ALICE
detector at the LHC, are reported. Within the experimental uncertainties and ranges covered by our
measurement, these ratios are independent of rapidity, transverse momentum and multiplicity for all
measured energies. The results are compared to expectations from event generators, such as PYTHIA and
HIJING/B, that are used to model the particle production in pp collisions. The energy dependence of p̄/p,
Λ/Λ, Ξ+/Ξ- and Ω+/Ω-, reaching values compatible with unity for √s = 7 TeV measurement of ALICE.
These dependencies can be described by exchanges with the Regge-trajectory intercept of αj ≈ 0.5, which
are suppressed with increasing rapidity interval Δy. Any significant contribution of an exchange not
suppressed at large Δy (reached at LHC energies) is disfavoured.
Budnikov, D., etc., Net-charge fluctuations in Pb-Pb collisions at √sNN=2.76 TeV
Physical Review Letters, 2013, 110 (15), art. no. 152301
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
We report the first measurement of the net-charge fluctuations in Pb-Pb collisions at √sNN=2.76 TeV,
measured with the ALICE detector at the CERN Large Hadron Collider. The dynamical fluctuations per
unit entropy are observed to decrease when going from peripheral to central collisions. An additional
reduction in the amount of fluctuations is seen in comparison to the results from lower energies. We
examine the dependence of fluctuations on the pseudorapidity interval, which may account for the dilution
of fluctuations during the evolution of the system. We find that the fluctuations at the LHC are smaller
compared to the measurements at the BNL Relativistic Heavy Ion Collider, and as such, closer to what has
been theoretically predicted for the formation of a quark-gluon plasma.
Budnikov, D., etc., Measurement of inelastic, single- and double-diffraction cross sections in protonproton collisions at the LHC with ALICE
European Physical Journal C, 2013, 73 (6), pp. 1-20
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
Measurements of cross sections of inelastic and diffractive processes in proton-proton collisions at LHC
energies were carried out with the ALICE detector. The fractions of diffractive processes in inelastic
collisions were determined from a study of gaps in charged particle pseudorapidity distributions: for single
diffraction (diffractive mass M X<200 GeV/c 2) σSD/σINEL = 0.21 ± 0.03, 0.20+0.07 -0.08, and
0.20+0.04 -0.07, respectively at centre-of-mass energies √s = 0.9, 2.76, and 7TeV; for double diffraction
(for a pseudorapidity gap Δη>3) σ DD/σ INEL=0.11±0.03,0.12±0.05, and 0.20+0.05 -0.04, respectively at
√s = 0.9, 2.76, and 7~\TeV. To measure the inelastic cross section, beam properties were determined with
van der Meer scans, and, using a simulation of diffraction adjusted to data, the following values were
obtained: σINEL = 62.8+2.4 -4.0 (model) ±1.2 (lumi) mb at √s = 2.76 TeV and 73.2+2.0 -4.6 (model) ±2.6
(lumi) mb at √s = 7 TeV. The single- and double-diffractive cross sections were calculated combining
relative rates of diffraction with inelastic cross sections. The results are compared to previous
measurements at proton-antiproton and proton-proton colliders at lower energies, to measurements by
other experiments at the LHC, and to theoretical models.
Budnikov, D., etc., Charged kaon femtoscopic correlations in pp collisions at √s=7 TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology, 2013, 87 (5), art. no. 052016
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
Correlations of two charged identical kaons (KchKch) are measured in pp collisions at √s=7 TeV by the
ALICE experiment at the Large Hadron Collider (LHC). One-dimensional KchKch correlation functions
are constructed in three multiplicity and four transverse momentum ranges. The KchKch femtoscopic
source parameters R and λ are extracted. The KchKch correlations show a slight increase of femtoscopic
radii with increasing multiplicity and a slight decrease of radii with increasing transverse momentum.
These trends are similar to the ones observed for ππ and Ks0Ks0 correlations in pp and heavy-ion
collisions. However at high multiplicities, there is an indication that the one-dimensional correlation radii
for charged kaons are larger than those for pions in contrast to what was observed in heavy-ion collisions
at the Relativistic Heavy-Ion Collid
Budnikov, D., etc., Transverse momentum distribution and nuclear modification factor of charged
particles in p+Pb collisions at √sNN=5.02 TeV
Physical Review Letters, 2013, 110 (8), art. no. 082302
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The transverse momentum (pT) distribution of primary charged particles is measured in minimum bias
(non-single-diffractive) p+Pb collisions at √sNN=5.02 TeV with the ALICE detector at the LHC. The p T
spectra measured near central rapidity in the range 0.5<p T<20 GeV/c exhibit a weak pseudorapidity
dependence. The nuclear modification factor RpPb is consistent with unity for pT above 2 GeV/c. This
measurement indicates that the strong suppression of hadron production at high pT observed in Pb+Pb
collisions at the LHC is not due to an initial-state effect. The measurement is compared to theoretical
calculations
Budnikov, D., etc., Long-range angular correlations on the near and away side in p-Pb collisions at
√sNN=5.02 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2013,719 (1-3), pp. 2941
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
Angular correlations between charged trigger and associated particles are measured by the ALICE detector
in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum
ranges within 0.5<pT,assoc<pT,trig<4 GeV/c. The correlations are measured over two units of
pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as
associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on
the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted
from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently
reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The
two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier
coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the
away side are equal within the uncertainties for all studied event multiplicity and pT bins, and the widths
show no significant evolution with event multiplicity or pT. These findings suggest that the near-side ridge
is accompanied by an essentially identical away-side ridge
Budnikov, D., etc., Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high
transverse momentum in Pb-Pb collisions at √sNN=2.76 TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2013,719 (1-3), pp. 1828
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The elliptic, v2, triangular, v3, and quadrangular, v4, azimuthal anisotropic flow coefficients are measured
for unidentified charged particles, pions, and (anti-)protons in Pb-Pb collisions at sNN=2.76TeV with the
ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle
cumulant methods are reported for the pseudo-rapidity range |η|<0.8 at different collision centralities and
as a function of transverse momentum, pT, out to pT=20GeV/c. The observed non-zero elliptic and
triangular flow depends only weakly on transverse momentum for pT>8GeV/c. The small pT dependence
of the difference between elliptic flow results obtained from the event plane and four-particle cumulant
methods suggests a common origin of flow fluctuations up to pT=8GeV/c. The magnitude of the (anti)proton elliptic and triangular flow is larger than that of pions out to at least pT=8GeV/c indicating that the
particle type dependence persists out to high pT.
Budnikov, D., etc., Coherent J/ψ photoproduction in ultra-peripheral Pb-Pb collisions at
sNN=2.76TeV
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 2013,718 (4-5), pp.
1273-1283
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The ALICE Collaboration has made the first measurement at the LHC of J/ψ photoproduction in ultraperipheral Pb-Pb collisions at sNN=2.76TeV. The J/ψ is identified via its dimuon decay in the forward
rapidity region with the muon spectrometer for events where the hadronic activity is required to be
minimal. The analysis is based on an event sample corresponding to an integrated luminosity of about 55
μb-1. The cross section for coherent J/ψ production in the rapidity interval -3.6<y<-2.6 is measured to be
dσJ/ψcoh/dy=1.00±0.18(stat)-0.26+0.24(syst)mb. The result is compared to theoretical models for coherent
J/ψ production and found to be in good agreement with those models which include nuclear gluon
shadowing.
Budnikov, D., etc., Pseudorapidity density of charged particles in p+Pb collisions at √sNN=5.02 TeV
Physical Review Letters, 2013, 110 (3), art. no. 032301
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The charged-particle pseudorapidity density measured over four units of pseudorapidity in nonsinglediffractive p+Pb collisions at a center-of-mass energy per nucleon pair √sNN=5.02 TeV is presented. The
average value at midrapidity is measured to be 16.81±0.71 (syst), which corresponds to 2.14±0.17 (syst)
per participating nucleon, calculated with the Glauber model. This is 16% lower than in nonsinglediffractive pp collisions interpolated to the same collision energy and 84% higher than in d+Au collisions
at √sNN=0.2 TeV. The measured pseudorapidity density in p+Pb collisions is compared to model
predictions and provides new constraints on the description of particle production in high-energy nuclear
collisions.
Budnikov, D., etc., Charge separation relative to the reaction plane in Pb-Pb collisions at √sNN=2.76
TeV
Physical Review Letters, 2013, 110 (1), art. no. 012301
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
Measurements of charge-dependent azimuthal correlations with the ALICE detector at the LHC are
reported for Pb-Pb collisions at √s NN=2.76 TeV. Two- and three-particle charge-dependent azimuthal
correlations in the pseudorapidity range |η|<0.8 are presented as a function of the collision centrality,
particle separation in pseudorapidity, and transverse momentum. A clear signal compatible with a chargedependent separation relative to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new insight for
understanding the nature of the charge-dependent azimuthal correlations observed at RHIC and LHC
energies.
Budnikov, D., etc., Centrality dependence of charged particle production at large transverse
momentum in Pb–Pb collisions at
Physics Letters B, 13 March 2013, 720 (1-3), pp. 52-62
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The inclusive transverse momentum (pT) distributions of primary charged particles are measured in the
pseudo-rapidity range |η|<0.8 as a function of event centrality in Pb-Pb collisions at √sNN=2.76TeV with
ALICE at the LHC. The data are presented in the pT range 0.15<pT<50GeV/c for nine centrality intervals
from 70-80% to 0-5%. The results in Pb-Pb are presented in terms of the nuclear modification factor RAA
using a pp reference spectrum measured at the same collision energy. We observe that the suppression of
high-pT particles strongly depends on event centrality. The yield is most suppressed in central collisions
(0-5%) with RAA≈0.13 at pT=6-7GeV/c. Above pT=7GeV/c, there is a significant rise in the nuclear
modification factor, which reaches RAA≈0.4 for pT>30GeV/c. In peripheral collisions (70-80%), only
moderate suppression (RAA=0.6-0.7) and a weak pT dependence is observed. The measured nuclear
modification factors are compared to other measurements and model calculations.
Budnikov, D., etc., Measurement of electrons from beauty hadron decays in pp collisions at
Physics Letters B, 10 April 2013, 721 (1-3), pp. 13-23
Russian Federal Nuclear Center (VNIIEF), Sarov, Russia
The production cross section of electrons from semileptonic decays of beauty hadrons was measured at
mid-rapidity (|y|<0.8) in the transverse momentum range 1<pT<8GeV/c with the ALICE experiment at the
CERN LHC in pp collisions at a center of mass energy s=7TeV using an integrated luminosity of 2.2nb-1.
Electrons from beauty hadron decays were selected based on the displacement of the decay vertex from the
collision vertex. A perturbative QCD calculation agrees with the measurement within uncertainties. The
data were extrapolated to the full phase space to determine the total cross section for the production of
beauty quark-antiquark pairs.