Explosion-resistance of the cylindrical part of a fast-reactor vessel

All-Russia Scientific-Research Institute of Electrophysical Apparatus. Special Office of Machine Design. Institute of High Temperatures, Russian Academy of Sciences. Translated from Atomnaya énergiya, Vol. 79, No. 3, pp. 178–188, September, 1995.     

Measurements of the viscosity of iron and uranium under shock compression

Interest in studying the viscosity of iron and uranium is primarily associated with studying the stability of motion of envelopes made of these materials towards the center in spherically symmetric systems during the acceleration of the envelopes by the products of explosion and by shock waves. The experimental measurements of viscosity in the pressure range from 30 to 250 GPa involve the use of the method of evolution of harmonic oscillation preassigned at the front of shock wave propagating in iron and uranium. The resultant data are considered along with the estimates of the thermodynamic state of matter under shock compression.     

Shock d eformation diagram of fireclay

A method is proposed for constructing the shock compression and load-relief diagrams of a foam material when a one-dimensional stress-strain is realized in it. The method is based on the mathematical analysis of experimental information. The shock-compression and load-relief diagrams of fireclay (strain rate ε=10² sec⁻¹) are constructed from the experimental data obtained in experiments on the compression of samples of this foam material. 5 figures. 10 references. NITs TIV OIVT RAN. Translated from Atomnaya énergiya, Vol. 88, No. 1, pp. 38–43, January, 2000     

Interaction of Oxide Melt with External-Trap Zirconium Dioxide Refractories

The results of an investigation of the interaction of zirconium dioxide refractories – ceramic and concrete with iron oxides – are presented. The investigations showed that starting at 1600 K in an argon atmosphere contact of a mixture of iron oxides with refractories gives rise to erosion of the latter. Under isothermal conditions (2270 K), ceramic with 16% porosity completely absorbs a melt with mass 1/7 of the ceramic mass. The concrete confines the same melt mass with a lower temperature 1870 K and, in the process, unlike the ceramic, it loses strength.The results obtained and the published data were used to analyze the operation of a refractory protective layer of an EPR trap.     

Measurement of Kinematic and Thermal Characteristics of High-Speed Gas-Dynamic Processes by Means of Microwave Sounding

The paper describes a method of simultaneous measurements of kinematic parameters of a high-speed process by a microwave radio interferometer with a 3-mm range of wavelengths and the brightness temperature of the same process by the microwave radio interferometer operating in the radiometer mode. The methods of radiometer calibration and analysis of radiometric data are described. Results of experimental investigations are reported by an example of measuring the detonation velocity and estimating the brightness temperature of the detonation front in TNT.     

A heat-insulating lightweight material

A technology for producing lightweight material suitable for service in unprotected linings up to temperatures 1300 – 1350°C is considered. The material has apparent density from 0.35 to 0.70 g/cm³ and exhibits good heat-insulating and strength parameters.     

Recent Developments in Unconventional Superconductivity Theory

A review of recent developments in unconventional superconductivity theory is given. In the first part I consider the physical origin of the Kerr rotation polarization of light reflected from the surface of superconducting Sr₂RuO₄. Then a comparison of magneto-optical responses in superconductors with orbital and spin spontaneous magnetization is presented. The latter result is applied to the estimation of the magneto-optical properties of neutral superfluids with spontaneous magnetization. The second part is devoted to the natural optical activity or gyrotropy properties of noncentrosymmetric metals in their normal and superconducting states. The temperature behavior of the gyrotropy coefficient is compared with the temperature behavior of paramagnetic susceptibility determining the noticeable increase of the paramagnetic limiting field in noncentrosymmetric superconductors. In the last chapter I describe the order parameter and the symmetry of the superconducting state in the itinerant ferromagnet with orthorhombic symmetry. Finally the Josephson coupling between two adjacent ferromagnetic superconducting domains is discussed.     

Decay of vortex state and mutual friction in superfluid3He-A

The time dependence of decaying superfluid circulation is studied in³He-A in a singly connected cylindrical geometry. Comparison with experimental data is discussed.     

Thermal Radiative Properties of Ceramic of Cubic ZrO2Stabilized with Y2O3at High Temperatures

The results are given of the investigation of the normally hemispherical reflectivity of ceramic of cubic zirconia stabilized with 8 mol % yttria for the wavelengths of 0.488, 0.6328, 1.15, and 1.39 m both in the process of its rapid heating in air by CO₂-laser radiation from room temperature to 3200 K and in the process of subsequent cooling after the heating radiation is discontinued. It is demonstrated that, in the entire investigated spectral range under conditions of a layer of melt 250–500 m thick on the surface, an optically infinite layer is realized in the melt, and the reflection is largely defined by the refractive index. This latter layer remains optically infinite even immediately after solidification; however, by the end of the solidification process, its reflectivity somewhat increases due to cracks and pores. Measurements of the reflection under conditions of continuous stepwise heating by fluxes of relatively low intensity and in the course of subsequent cooling have produced data on the reflectivity of the layer under close-to-isothermal conditions. Some estimates are made of the values of the absorption coefficient of the melt.