Structure of salts solution in polar dielectric liquids and electrically induced separation of solvated ions

The aim of study is to demonstrate that separation of solvated ions in solution of mix of salts under the action of external periodic electric field happens because of around ions there are formed clusters consisting of molecules of solvent and the sizes of such clusters have dimensions ~ 0.1 [mu]m. In investigations the sizes of clusters theoretically were defined and experimentally value of frequency of external electric field which action excites the effect of separation of the solvated ions was defined. Experiments were done in the Technical Physics Chair of the National Research Tomsk Polytechnic University. At theoretical determination of the dimensions of clusters Poisson's equation was solved and was considered that polar molecules of solvent are oriented under the action of electric field of an ion. The chemical composition of samples of solutions was determined by means of the spectrophotometry and he X-ray excited fluorescent radiation analysis method. Theoretical estimates and results of experiments confirmed the assumption that clusters which are formed around ions in solutions have the dimensions ~ 0.1 [mu]m. Results of investigation testify that placing of volume distributed electric charge of ion in dielectric liquid is accompanied by formation of the supramolecular particles, which we called "clusters", linear sizes of which is significantly more than first and second radiuses of solvation (~ 1 Angstrom) and reach size ~ 0.1 [mu]m. At such sizes inertial properties of clusters and their natural frequencies give the chance to operate their movement by means of action of external electric field on solution

Self-propagating high-temperature synthesis of the high- current emission lanthanum and niobium contained ceramics

The paper describes the production of metal-ceramic high-current emitters containing lanthanum hexaboride LaB[6] by self-propagating high-temperature synthesis. Tests of emitters as explosive-emission cathodes in an OMEGA-350 microsecond accelerator are presented. Experiments show that when a metal-ceramic cathode is used, the emitted energy was 12-17% higher than that produced by tungsten and graphite cathodes and the beam "signature" is a circle with a small (~ 15%) variation in radius

Application of the Gadolinium Isotopes Nuclei Neutron-Induced Excitation Process

The possibility of transformation of energy of fast and epithermal neutrons to energy of coherent photon radiation at the expense of a neutron pumping of the active medium formed by nucleus with long-living isomerous states is theoretically described. The channel of the nucleus formation in isomeric state as a daughter nucleus resulting from the nuclear reaction of neutron capture by a lighter nucleus is taken into consideration for the first time. The analysis of cross sections’ dependence of radiative neutron capture by the nuclei of gadolinium isotopes Gd155 and Gd156 is performed. As a result, it is stated that the speed of Gd156 nuclei formation exceeds the speed of their “burnup” in the neutron flux. It is provided by a unique combination of absorbing properties of two isotopes of gadolinium Gd155 and Gd156 in both thermal and resonance regions of neutron energy. Conditions required for making isotope nuclei excited by forward neutron scattering on nuclei and for storing nuclei in excited states are formulated. The possibility of excess energy accumulation in the participating medium created by the nuclei of the pair of gadolinium isotopes Gd155 and Gd156 due to formation and storage of nuclei in isomeric state at radiative neutron capture by the nuclei of the stable isotope with a smaller mass is shown. It is concluded that when the active medium created by gadolinium nuclei is pumped by neutrons with the flux density of the order of 1013 cm−2 s−1, the condition of levels population inversion can be achieved in a few tens of seconds. The wave length of the radiation generated by the medium is 0.0006 nm

Particularities of spatial kinetics of hybrid thorium reactor installation containing the long neutron source based on magnetic trap

In this work, we study the features of the spatial kinetics of installation as a hybrid thorium reactor with an elongated plasma neutron source based on a magnetic trap. The active zone of the installation under study consists of an assembly of hexagonal fuel blocks of a unified design and a long solenoid with a high-temperature plasma column passing through the axial region of the core. Combining engineering expertise in creating nuclear reactors with a physics-technical potential for obtaining high-temperature plasma in a long magnetic trap we ensure the solution of the multidisciplinary problem posed. These studies are of undoubted practical interest, since they are necessary to substantiate the safety of operation of such hybrid systems. The research results will allow optimizing the active zone of the hybrid system with leveling the resulting offset radial and axial energy release distributions. Results of our study will be the basis for the development of new and improvement of existing methods of criticality control in related systems such as "pulsed neutron source - subcritical fuel assembly"

Analysis constants for database of neutron nuclear data

At present there is a variety of experimental and calculation nuclear data which arerather entirely presented in the following evaluated nuclear data libraries: ENDF (USA), JEFF(Europe), JENDL (Japan), TENDL (Russian Federation), ROSFOND (Russian Federation).Libraries of nuclear data, used for neutron-physics calculations in programs: Scale (OrigenArp),MCNP, WIMS, MCU, and others. Nevertheless all existing nuclear data bases, includingevaluated ones, contain practically no information about threshold neutron reactions on {232}Thnuclei; available values of outputs and cross-sections significantly differ by orders. The workshows necessity of nuclear constants corrections which are used in the calculations of grids andthorium storage systems. The results of numerical experiments lattices and storage systemswith thorium

Study of Plasmachemical Synthesis of Fuel Compositions for Dispersion Nuclear Fuel

The paper presents the results of studies of the plasmachemical synthesis of fissile material (uranium dioxide) and the matrix (yttria) for dispersion nuclear fuel. For this purpose, simulated water-organic solutions of zirconyl nitrate, yttrium nitrate and organic component (acetone) have been used. For the first time, the compositions of such solutions and the modes of their processing, which ensure the synthesis of nanosized oxide powders in air plasma, were determined

Dynamics of population of gadolinium-156 nuclei energy levels during neutron pumping of isotope-modified gadolinium oxide

The possibility of transformation of energy of fast and epithermal neutrons to energy of coherent photon radiation at the expense of a neutron pumping of the active medium formed by nucleus with long-living isomerous states is theoretically described. The channel of the nucleus formation in isomeric state as a daughter nucleus resulting from the nuclear reaction of neutron capture by a lighter nucleus is taken into consideration for the first time. The analysis of cross sections dependence of radiative neutron capture by the nuclei of gadolinium isotopes Gd155 and Gd156 is performed. As a result, it is stated that the speed of Gd156 nuclei formation exceeds the speed of their “burnup” in the neutron flux. It is provided by a unique combination of absorbing properties of two isotopes of gadolinium Gd155 and Gd156 in both thermal and resonance regions of neutron energy. The possibility of excess energy accumulation in the participating medium created by the nuclei of the pair of gadolinium isotopes Gd155 and Gd156 due to formation and storage of nuclei in isomeric state at radiative neutron capture by the nuclei of the stable isotope with a smaller mass is shown. It is concluded that when the active medium created by gadolinium nuclei is pumped by neutrons with the flux density of the order of 1013 cm-2·s-1, the condition of levels population inversion can be achieved in a few tens of seconds. The wave length of the radiation generated by the medium is 0.0006 nm

Gas-Cooled Thorium Reactor with Fuel Block of the Unified Design

Scientific researches of new technological platform realization carried out in Russia are based on ideas of nuclear fuel breeding in closed fuel cycle and physical principles of fast neutron reactors. Innovative projects of low-power reactor systems correspond to the new technological platform. High-temperature gas-cooled thorium reactors with good transportability properties, small installation time, and operation without overloading for a long time are considered perspective. Such small modular reactor systems at good commercial, competitive level are capable of creating the basis of the regional power industry of the Russian Federation. The analysis of information about application of thorium as fuel in reactor systems and its perspective use is presented in the work. The results of the first stage of neutron-physical researches of a 3D model of the high-temperature gas-cooled thorium reactor based on the fuel block of the unified design are given. The calculation 3D model for the program code of MCU-5 series was developed. According to the comparison results of neutron-physical characteristics, several optimum reactor core compositions were chosen. The results of calculations of the reactivity margins, neutron flux distribution, and power density in the reactor core for the chosen core compositions are presented in the work