2010

Medvedev A. B. Crater formation possibly associated with an ascending thermal plume  //  New Concepts in Global Tectonics Newsletter, no. 56, September, 2010, С. 86 - 98

Russian Federal Nuclear Center ( VNIIEF ), Sarov, Russia

The hypothetical possibility of a qualitative explanation of large crater formation on the surfaces of the Moon and Mercury is discussed in terms of the concept of thermal mantle plumes. Prerequisites for this hypothesis are revealed on the assumption that the mantle medium possesses a negative coefficient of thermal expansion. This anomaly reduces the buoyancy of hot plume material ( a substance should be sufficiently overheated for the ascent in order to overcome a density barrier, caused by the anomaly ), allows cold peripheral material ( surrounding the ascended plume ) to be pushed away; causes compaction ( under horizontal heat exchange ) of the vertical zone where the column plume contacts the surrounding medium in the early stages after the plume ascent; and leads to compaction of the deep mantle due to the long-term heat supply. Such phenomena can lead to vertical craterlike deformations of the crust in areas of ascending large column - plumes. Significant implications of such an anomaly for geophysical processes can also be proposed. The present paper describes the hypothesis, originally proposed by the author in 2008, expounded more systematically and with a series of additions.

Zheivot V. I.^a, Molchanov V. V.^a, Zaikovskii V. I.^a, Krivoruchko V. N.^a, Zaitseva N. A.^a, Shchuchkin M. N.^b  Carbon xerogels: nano - and adsorption textures, chemical nature of the surface and gas chromatography properties  //  Microporous and Mesoporous Materials. 2010. Т. 130. № 1 - 3. С. 7 - 13.

^a Boreskov Institute of Catalysis SB RAS, pr. Akademika Lavrent’eva 5, Novosibirsk 630090, Russia

^b Russian Federal Nuclear Center ( VNIIEF ), Sarov, Nizhnii Novgorod Region, Russia

Nano - and adsorption textures, gas chromatography features of carbon xerogels obtained by carbonization of phenol - formaldehyde resins have been studied. The properties of carbon xerogels were compared with those of carbon - containing and silica - alumina adsorbents. Depending on carbonization, they have properties typical of carbons or carbons combined with silica - alumina materials. The application of carbon xerogels in practical gas chromatography has been exemplified.

Boriskov G. V., Belov S. I., Bykov A. I., Dolotenko M. I., Egorov N. I., Korshunov A. S., Kudasov Yu. B., Makarov I. V., Selemir V. D., Filippov A. V.  Conductivity and permittivity of hydrogen under isentropic magnetic compression up to 3 mbar  //  Journal of Low Temperature Physics. 2010. Т. 159. № 1 - 2. С. 307 - 310.

Russian Federal Nuclear Center ( VNIIEF ), Sarov, Russia

An experimental technique for isentropic compression of solid and liquid substances up to ultrahigh pressures is discussed. A pulsed ultrahigh magnetic field up to 1000 T is produced by an explosive flux - compression generator MC - 1. A smooth shock - free pulse of pressure in a coaxial metal chamber of few cubic centimeters is obtained. A radio - frequency technique of conductivity and permittivity measurement is applied. The conductivity of solid hydrogen isentropic ally compressed with the initial temperature less that 14 K was estimated at about 1 ( Ohm·m )^-1  under the pressure of 3 Mbar. A sharp rise of the relative permittivity as a precursor of a metal - insulator transition was observed.

Kudasov Y. B., Korshunov A. S., Pavlov V. N., Maslov D. A.  Relaxation and magnetization dynamics of frustrated spin - chain systems   //   Journal of Low Temperature Physics. 2010. Т. 159. № 1 - 2. С. 76 - 79.

Russian Federal Nuclear Center ( VNIIEF ), Sarov, Russia

A 3D model of the magnetization dynamics in frustrated triangular spin-chain systems Ca₃Co₂O₆   is proposed. This model is a generalization of the 2D model developed earlier. The spins are assumed to interact with the nearest neighbors and external agency ( heat reservoir and external magnetic field )  that causes them to change their states randomly with time. A probability of a single spin - flip process is assumed in a Glauber - like form. The 3D model allows describing the step - like behavior of a magnetization curves experimentally observed in a strong magnetic field.

Kaminskii M. V., Kopytov G. F., Mogilev V. A., Travov Y. F., Faikov Y. I.   Penetration of a copper rod into a sandy target   //   Journal of Applied Mechanics and Technical Physics. 2010. Т. 51. № 3. С. 324 - 331.

Russian Federal Nuclear Center ( VNIIEF ), Sarov, Russia

This paper presents the results of experimental and theoretical studies of high-velocity penetration of cylindrical copper rods into sand. The hydrodynamic Alekseevskii - Tate theory is modified to determine the penetration depth and wear velocity of the material of the rod penetrating into soil target in the plastic and hydrodynamic stages of penetration. The case where the target material is significantly less strong than the rod ( impactor ) material is considered.

Bragunets V. A., Simakov V. G., Borisenok V. A., Borisenok S. V., Kruchinin V. A.   Shock - induced electrical conductivity in some ferroelectrics   //   Combustion, Explosion, and Shock Waves. 2010. Т. 46. № 2. С. 231 - 236.

Russian Federal Nuclear Center (VNIIEF), Sarov, Russia

This paper gives the results of measurement of shock - induced electrical conductivity in ferroelectrics: PKR - 1  lead zirconate - titanate piezoceramic, deuterated triglycerine sulphate single crystal, and polymer polyvinylidene fluoride.

Drennov O. B.   Effect of material strength on the rotation dynamics of a plate driven by sliding detonation of an explosive charge   //   Combustion, Explosion, and Shock Waves. 2010. Т. 46. № 3. С. 365 - 369.

Russian Federal Nuclear Center ( VNIIEF ), Sarov, Russia

Experiments revealed different rotation dynamics of plates driven by a sliding detonation wave if the plates were made of materials with close physical properties but different strength. By modifying the existing formula for the bending angle, it was possible to describe the experimental data in a unified manner. Accounting for the dynamic strength of metal allowed prediction of the formula for the bending angle for one material based on the known formula for another material with close physical properties.

Generalova V. V., Zhanzhora A. P., Koshelev A. S., Narozhnyi A. T.   A specialized source of gamma radiation that is spatially coincident with the mop - k2 modeling neutron reference field   //   Measurement Techniques. 2010. Т. 53. № 1. С. 379 - 385.

Russian Federal Nuclear Center ( VNIIEF ), Sarov, Russia

A specialized source of gamma radiation based on a horizontal loading container in the active zone of the  BR - K1  reactor is metrologically investigated and certified. The source is intended for calibration of dosimeters and detectors of the gamma component of mixed radiation.

Abramov I. A., D'Yanov N. Y., Kazakovskii N. T.  Technical approaches in the mass spectrometric analysis of hydrogen and helium isotopes   //   Instruments and Experimental Techniques. 2010. Т. 53. № 1. С. 115 - 117.

Russian Federal Nuclear Center ( VNIIEF ), Sarov, Russia

A method of mass spectrometric analysis of gas mixtures of hydrogen and helium isotopes on  low - resolution units is proposed. The method is based on the dependence of the ion current intensity on the partial pressure of the gas in the puffing system of the mass spectrometer. The appropriate laboratory procedure for performing the mass spectrometric analysis with simultaneous recording of the mass spectrum and absolute gas pressure in the puffing system of the mass spectrometer is designed. It was shown that it is possible to identify completely overlapping peaks of ion currents of components of the gas mixture, and this is confirmed by the measurement results.

Zakharov A. E., Ignat'Ev N. G., Krapiva P. S., Zhidkov N. V., Bessarab A. V., Suslov N. A.   First results of use of a scintillating - fiber position - sensitive detector for recording the target image in a 14 - mev neuron beam at the Iskra - 5 facility   //   Instruments and Experimental Techniques. 2010. Т. 53. № 2. С. 161 - 164.

Russian Federal Nuclear Center ( VNIIEF ), Sarov, Russia

The design of the scintillating-fiber detector is described, and the first results obtained in recording the target image in a 14 - MeV neutron beam at the  «Iskra – 5»  facility are presented. The scintillating - fiber position - sensitive detector has been designed for diagnosing laser fusion processes by recording the spatial distribution of thermonuclear neutrons escaping from the target.  Position - sensitive detection is effected by conversion of neutron radiation into light in a scintillating fiber array. Discrimination of neutrons from γ rays by their time of flight and image intensification is performed with the aid of a frame camera. Images are recorded by a CCD camera. A technique for recording penumbra images is used for imaging at low neutron yields ( 3 × 10⁸ - 10¹¹ ).