Статьи в зарубежных периодических изданиях

Bogachev A.V.¹, Garanin S.G.¹, Dudov A.M.¹, Eroshenko V.A.¹, Kulikov S.M.¹, Pautov V.O.¹, Rus A.V.¹, Sukharev S.A.¹, Mikaelian G.T.2, Panarin V.A.²  Diode - pumped caesium vapour laser with closed - cycle laser - active medium circulation // QUANTUM ELECTRON, 2012, 42 (2), 95 – 98.

 

¹ RFNC - VNIIEF, Sarov, Russia

² OJSC Research and Manufacturing Enterprise ‘Inject’, prosp. Saratov, Nizhnii Novgorod region, Russia

The creation of a caesium vapour laser with closed-cycle circulation of the laser-active medium is first reported. The power of the laser radiation amounted to ~ 1 kW with the "light - to -l ight" conversion efficiency of ~ 48 %. Quasi - two - dimensional computational model of the laser operation that provides adequate description of experimental results is considered. Calculated and experimental dependences of the laser radiation power on the temperature of the cuvette walls, laser medium pressure and pump power are presented.

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Bondarenko S.V., Garanin S.G., Zhidkov N.V., Pinegin A.V., Suslov N.A. Experimental investigation of X - ray spectral absorption coefficients in heated Al and Ge on the Iskra - 5 laser facility // QUANTUM ELECTRON, 2012, 42 (1), 51 – 57.

RFNC - VNIIEF, Sarov, Russia

We set forth the data of experimental investigation of X - ray spectral absorption coefficients in the 1,1 - 1,6 keV photon energy range for Al and Ge specimens bulk heated by soft X - ray radiation. Two experimental techniques are described: with the use of one facility channel and the heating of specimens by the X - ray radiation from a plane burnthrough target, as well as with the use of four channels and the heating by the radiation from two cylindrical targets with internal input of laser radiation. The X - ray radiation absorption coefficients were studied by way of transmission absorption spectroscopy using backlighting X - ray radiation from a point source. The results of investigation of X - ray spectral absorption coefficients on the 1s  - 2p transitions in Al atoms and the 2p  - 3d transitions in Ge atoms are presented.

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Brendel V.M.¹, Bukin V.V.¹, Garnov S.V.¹, Bagdasarov V.Kh.¹, Denisov N.N.¹, Garanin S.G.², Terekhin V.A.², Trutnev Yu.A.²   Fabrication of alkali halide UV photocathodes by pulsed laser deposition // QUANTUM ELECTRON, 2012, 42 (12), 1128 – 1132.

¹ A. M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow, Russian Federation

² RFNC - VNIIEF, Sarov, Russia

A technique has been proposed for the fabrication of atmospheric corrosion resistant alkali halide UV photocathodes by pulsed laser deposition. We produced photocathodes with a highly homogeneous photoemissive layer well - adherent to the substrate. The photocathodes were mounted in a vacuum photodiode, and a tungsten grid was used as an anode. Using pulsed UV lasers, we carried out experiments aimed at evaluating the quantum efficiency of the photocathodes. With a dc voltage applied between the photocathode and anode grid, we measured a shunt signal proportional to the total charge emitted by the cathode exposed to UV laser light. The proposed deposition technique enables one to produce photocathodes with photoemissive layers highly uniform in quantum efficiency, which is its main advantage over thin film growth by resistive evaporation.

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Bogachev V.A., Garanin S.G., Dolgopolov Yu.V., Kopalkin A.V., Kulikov S.M., Starikov F.A., Sukharev S.A., Feoktistov V.V.  Phasing of multichannel laser radiation upon stimulated Brillouin scattering // QUANTUM ELECTRON, 2012, 42 (6), 531 – 534

RFNC - VNIIEF, Sarov, Russia

We investigated the phasing of pulsed two- and fourchannel laser beams due to phase conjugation upon transient stimulated Brillouin scattering (SBS) in a double-pass amplification scheme. A high quality of beam phasing was experimentally demonstrated with the use of a microlens raster and an angular selector in the SBS - mirror scheme. The data obtained in the numerical simulation of transient SBS are in good agreement with experimental ones.

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Andreev S.N.¹, Yeremicheva Yu.I.¹, Rukhadze A.A.¹, Tarakanov V.P.1, Garanin S.G.², Yakutov B.P.²  Optimisation of neutron yield under ultra-intense laser impact on deuterated polyethylene targets // QUANTUM ELECTRON, 2012, 42 (7), 600 – 604

¹ A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow, Russian Federation

² RFNC - VNIIEF, Sarov, Russia

The modelling of interaction of ultra - intense femtosecond laser pulses with deuterated polyethylene targets is carried out with the processes of multiple field ionisation of the target atoms and the emission of neutrons produced in the course of the fusion reaction at high - energy deuteron collisions taken into account. The possibility of essential increase in the neutron yield (by tens of times) when using layered deuterated polyethylene targets with optimal dimensions of the layers and interlayer separations ~ 1 μm is demonstrated.

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Andreev N.F.¹, Vlasova K.V.¹, Davydov V.S.¹, Makarov A.I.¹,  Freidman G.I.¹, Shubin S.V.¹, Kulikov S.M.², Sukharev S.A.²  Cascaded frequency doublers for broadband laser radiation // QUANTUM ELECTRON, 2012, 42 (10), 887 – 898.

¹ Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod, Russian Federation

² RFNC - VNIIEF, Sarov, Russia

A new scheme of a cascaded converter of the first harmonic of broadband cw laser radiation into the second harmonic (SH) with compensation for the group walk - off in cascades is proposed and investigated. The conditions under which high conversion coefficients of broadband (~ 33 cm^-1) single - mode fibre laser radiation with low peak power (~ 300 W) into the SH are determined for frequency doublers based on the most promising LBO crystal. Conversion of cw radiation with an average power of 300 W and efficiency η = 4,5 % into the SH is obtained in a single LBO crystal. Effect of coherent addition of SH radiation excited in different cascades is demonstrated for two- and three-stage schemes. The expected conversion efficiencies, calculated disregarding loss but taking into account real aberrations of elements, are 18 % and 38 %, respectively. The effect of pumping depletion begins to manifest itself in the third cascade of a three-stage converter; it may reduce the latter value to ~ 30 %.

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Georgievskaya A.B., Raevsky V.A. Estimation of spectral characteristics of particles ejected from the free surfaces of metals and liquids under a shock wave effect. // AIP Conference Proceedings 17th Biennial Conference of the American Physical Society Topical Group on Shock Compression of  Condensed Matter, 2011 APS SCCM. Series "Shock Compression of Condensed Matter - 2011 - Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter" Chicago, IL, 2012. С. 1007 - 1010

 

RFNC - VNIIEF, Sarov, Russia

Approximate equations were obtained for estimating of the quantity of the surface-ejected mass vs. time for small initial perturbations. Numerical calculations confirmed the correctness of the estimates. The authors of this effort present approximate equations for estimating the spectral characteristics of particles ejected from the substance surface under shock wave loading in the liquid and solid states. The calculated spectra of particles are compared to results of tests performed in RFNC - All - Russia Research Institute of Experimental Physics (RFNC - VNIIEF) for determination of spectral structure of formed particles. Pressure and surface roughness were varied in these tests.

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Arinin V.A., Kryuchkov D.V., Ogorodnikov V.A., Raevsky V.A., Panov K.N., Peshkov V.V., Skokov V.I., Tyupanova O.A. Spall fracture of beryllium under shockwave loading // AIP Conference Proceedings 17th Biennial Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter, 2011 APS SCCM. Series "Shock Compression of Condensed Matter - 2011 - Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter" Chicago, IL, 2012. С. 1073 - 1076.

RFNC-VNIIEF, Sarov, Russia

We present investigations of beryllium spall fracture with samples of dimensions Ø 65×7 mm, which were made via vacuum hot pressing. Samples were loaded at normal incidence by a detonation wave of the explosive charge of TG 5/5 composition, 7, 14 and 30 mm in thickness, which gave shockwave stresses of 21 - 25 GPa within the sample. Spall fractures formed as the sample unloading at an air gap. A velocity profile was measured at the free boundary using VISAR laser interferometer, a spall layer thickness was measured with two - frame impulse X - ray radiography, and the shockwave profile was measured via a manganin - based gauge in a fluoroplastic base in the course of deceleration of a spall layer and of a basic part of beryllium. Hugoniot dynamic yield strength (YHE) and spall strength (σP) were measure as 0,69 - 0,73 GPa and 0,85+/-0,03 GPa, respectively, at a strain rate of ε ~10⁴ s^-1 in the unloading part of the incident pulse. A weak dependence between the spall layer thickness and HE layer thickness was recorded in tests. The weak dependence is not described through existing damage models and points to the need to develop more sophisticated models.

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Ignatova O.N., Raevsky V.A., Nadezin S.S. Growth of defining relations of beryllium // AIP Conference Proceedings 17th Biennial Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter, 2011 APS SCCM. Series "Shock Compression of Condensed Matter - 2011 - Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter" Chicago, IL, 2012. С. 1145 - 1148.

RFNC - VNIIEF, Sarov, Russia

The paper presents the results for construction of defining relations of beryllium. The phenomenological elastic-plastic relaxation model is utilized to calculate the deviatoric component of a shear stress. A spherical component of stress tensor is expressed through the equation of state in the form of Mie - Gruneisen. Melting temperature dependence on density is determined on the basis of the equation of Lindeman. The model takes account of strain and compression hardening, thermal softening, stress history, as well as relaxation of elastic stress.

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Zhernokletov M.V., Arinin V.A., Buzin V.N., Grigorieva Yu.A., Davydov N.B., Khrustalev V.V. Quasi - isentropic compression of gaseous helium in pressure range from 130 to 460 GPa  // AIP Conference Proceedings 17th Biennial Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter, 2011 APS SCCM. Series "Shock Compression of Condensed Matter - 2011 - Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter" Chicago, IL, 2012. С. 1411 - 1414.

RFNC - VNIIEF, Sarov, Russia

Here we present the results for experiments of gaseous helium with an initial density of 0,019 g/cm³ cylindrically compressed. The cylindrical compression technique transforms shock compression to quasi-isentropic compressions. The resulting pressures attained were from 130 to 460 GPa with compressed densities of 1,3 to 2,3 g/cm³ for a compression ratio (ε = ρ/ρ₀ ) from 70 to 115. The density of the gas was determined from X - ray radiography based on the boundary location of the steel liners, which compressed the gas. The pressures Gas density was determined by the X - ray radiography method basing on location of boundaries of the steel shells, which compressed gas. Pressures were based upon gas-dynamic calculations.