Method for recording of solar neutrinos with a lithium detector

A method for solar neutrino recording on a laboratory bench with a lithium detector is developed. The efficiency of extraction of beryllium from lithium as high as 96.4% is achieved, and it is shown that lithium extraction losses are less than 1%. The results of a full-scale experiment with a 10-t lithium detector consisting of 20 500-kg modules are presented. Technical solutions based on the experimental results open the way to designing a pilot facility intended for 500 kg of lithium.     

Beam-foil spectra of the highly ionized sulfur

Spectra of carbon, boron, beryllium, lithium, belium and hydrongen-line for sulfur obtained at an energy of 80 MeV, wherein thirty-four lines have been identified. Analysis of the spectra was based on theoretical results and other experimental data.     

Pseudofermion ferromagnetism in the Kondo lattices: a mean-field approach

Research into new materials to be used as hydrogen reservoirs is necessary, the increasing demand of energy in the world should be covered progressively by clean energies, trying not to pollute the environment. With this work we wish to contribute to the knowledge of the different saline hydrides and the possibility of using these as hydrogen reservoirs. We performed a systematic study on these materials. In this work we used different ab-initio codes to study several compounds of lithium and beryllium with hydrogen.     

Laser spectroscopy with a cooler ring at the esr (GSI) and the TSR (MPI Heidelberg)

At the TSR cooler ring at Heidelberg, laser studies were carried out using singly charged lithium and beryllium ions. Laser spectroscopy of relativistic lithium ions (v=0.04c) yielded signals with a narrow linewidth, suitable for an experimental test of special relativity. A dramatic reduction of the beam temperature, as defined by the longitudinal velocity spread, was achieved via laser cooling in both cases. At the ion energies available at ESR it will become possible to prepare and store bare ions up to U⁹²⁺. Electron cooling was succesfully demonstrated for hydrogen-like Bi⁸²⁺ ions, where a laser experiment is scheduled to study the ground-state hyperfine splitting.     

Quadrupole Interaction Contribution to the Hyperfine Structure of P-States in Muonic Lithium,Beryllium, and Boron Ions

The contribution of the quadrupole interaction to the hyperfine structure of the spectrum of the energy of muonic lithium, beryllium, and boron ions is calculated within the quasipotential method in quantum electrodynamics. The numerical results obtained improve previous calculations due to the consideration of new corrections. They can be used for comparison with future experimental data.     

Plasmon coupling to core holes in simple metals

Soft X-ray appearance potential data for the metals lithium and beryllium are presented. The plasmon satellite structure is compared in both cases with recently available XP-spectra. For s-metals in general, the plasmon coupling constant in APS seems to be smaller than in the corresponding XPS experiment. Assuming the interaction to be primarily intrinsic, one would expect the coupling constants to be identical.     

Damage of beryllium surface under irradiation with a high-current electron beam

Radiation damage of a beryllium surface by a high-current electron beam at the GSEP-3 accelerator is considered. The degree of damage of beryllium samples has been determined. The temperature fields inside the sample and the distributions of thermal stresses have been calculated. The reasons for beryllium surface cracking formation have been found. The concentrations of point defects have been calculated. The possible reasons for an increase in microhardness of the irradiated beryllium surface layer are discussed.     

Lithium experiment on solar neutrinos to weight the CNO cycle

The measurement of the flux of beryllium neutrinos with an accuracy of about 10% and CNO neutrinos with an accuracy of 20–30% will enable one to find the flux of pp neutrinos in the source with an accuracy better than 1% using the luminosity constraint. The future experiments on νe^? scattering will enable one to measure with very good accuracy the flux of beryllium and pp neutrinos on the Earth. The ratio of the flux of pp neutrinos on the Earth and in the source will enable one to find with very good accuracy a mixing angle θ_⊙. A lithium detector has high sensitivity to CNO neutrinos and can find the contribution of the CNO cycle to the energy generated in the Sun. This will be a stringent test of the theory of stellar evolution and combined with other experiments will provide a precise determination of the flux of pp neutrinos in the source and a mixing angle θ_⊙. The work on the development of the technology of a lithium experiment is now in progress.     

氢、氮、铍、锂原子在缺陷富勒烯C_x(X=58～62)中的吸附与渗透

碳富勒烯包合物由于潜在的应用前景受到广泛关注.我们采用第一性原理方法计算了氢、氮、锂、铍原子在不同碳富勒烯中的吸附和穿越.根据原子在不同碳富勒烯笼中的势能曲线,我们给出了原子穿越碳富勒烯笼的势垒和势阱,归纳出原子穿越碳笼机理分为插入机理、渗透机理以及插入机理和渗透机理的混合机理.     

Equilibrium geometries and electronic properties of BenLi （n=2-15） clusters from first principles

This paper studies the equilibrium geometries and electronic properties of Ben and BenLi clusters, up to n=15, by using density-functional theory（DFT） at B3LYP/6-31G（d） level. The lowest-energy structures of Ben and BenLi clusters were determined. The results indicate that a single lithium impurity enhances the stability and chemical reactivity of the beryllium clusters. It finds that the geometries of the host clusters change significantly after the addition of the lithium atom for n ≥8. The lithium impurity prefers to be on the periphery of beryllium clusters, and occupies vertex sites. Both Be4Li, Be9Li, and Be13Li were found to be particularly stable with higher average binding energy, local peaks of second-order energy difference and fragmentation energies. For all the BenLi clusters studied, we found charge transfers from the Li to Be site and co-existence of covalent and metallic bonding characteristics.     

氢、氮、铍、锂原子在缺陷富勒烯CX（x=58-62）中的吸附与渗透

碳富勒烯包合物由于潜在的应用前景受到广泛关注。我们采用第一性原理方法计算了氢、氮、锂、铍原子在不同碳富勒烯中的吸附和穿越。根据原子在不同碳富勒烯笼中的势能曲线,我们给出了原子穿越碳富勒烯笼的势垒和势阱,归纳出原子穿越碳笼机理分为插入机理、渗透机理以及插入机理和渗透机理的混合机理。     

Evaluation of new single crystal piezoelectric materials for surface acoustic-wave applications

Surface acoustic waves (SAW), or Rayleigh waves, bound to the surfaces of piezoelectric materials are becoming rapidly significant in electronic device applications, particularly as VHF-UHF frequency filters and versatile time-domain processors. The majority of available devices utilize either signle crystalline quartz or lithium niobate as the piezoelectric medium. This paper describes briefly the growth and critical evaluation of SAW impedance and propagation properties for certain new single crystal piezoelectric materials. Crystals discussed are Czochralski-grown bismuth germanium oxide, films of zinc oxide and aluminum nitride both epitaxially grown on single crystal sapphire, and flux-grown beryllium oxide. It is concluded that bismuth germanium oxide may prove an important cost-effective alternative to both quartz and lithium niobate, and that either zinc oxide or aluminum nitride is destined to prove invaluable in the realization of monolithic circuits such as programmable tapped delay lines, in which SAW will be interfaced with metal-oxide semiconductor (large scale integrated) technology, and active SAW elements employing functional integration.     

Formation of a metallic layer from individual atoms

Adsorption of copper, gold and beryllium on (110), (100), and (211) single-crystal planes of tungsten leads to essentially different work-function changes. It is known from numerous investigations of alkali-metal adsorption on metal substrates that the work-function variation reflects the electronic processes occurring during the formation of the adlayer. It is obvious that copper, gold and beryllium adsorption is accompanied by a wide variety of physical processes different from those appearing in alkali-metal adsorption. The existing experimental data concerning work-function changes induced by copper, gold and beryllium adsorption are compiled. A model is developed, which may explain these changes.     

Limiting role of desorption in hydrogen transport across a deposited beryllium film

Hydrogen transport across a deposited beryllium layer has been investigated using the hydrogen permeability and concentration pulse methods. A layer of beryllium was deposited on a prepurified nickel membrane by cathode sputtering in a glow discharge plasma in “especially pure” grade hydrogen. An analysis of the experimental results showed that the main limiting process for hydrogen transport is desorption from the layer rather than diffusion in the bulk of the layer. A mathematical transport model is proposed and used to determine the rate constant of hydrogen desorption from beryllium. Zh. Tekh. Fiz. 68, 128–130 (January 1998)     

铍组件堆内长期服役后的尺寸测量

铍是核反应堆内的重要反射层材料,其辐照后的尺寸变化对反应堆的安全性具有重要的影响。为获得铍组件堆内长期服役后的尺寸变化,以对其堆内的服役性能评价提供基础数据,设计并加工了一套高放样品远程转运平台,使用三坐标测量机完成了绵阳SPRR-300堆内铍组件的尺寸变化测量实验。实验测量结果表明,SPRR-300堆的铍组件在服役29 a后,在最高中子通量高达6.78×1021 cm?2的辐照环境下,铍组件外形尺寸总体上保持良好,截面有微量的收缩变形,最大形变约0.13 mm,这表明在长期中子辐照环境下,辐照蠕变是导致铍组件尺寸变化的主要原因。     

Study of the Interaction of Plasma with Beryllium That Is a Candidate Material for the First Wall of a Fusion Reactor

The experimental conditions for treatment of a candidate material of the first wall, beryllium, by the plasma have been determined. The plasma parameters obtained using the simulator with a plasma-beam setup during the irradiation of samples as well as the results of material studies obtained by scanning electron microscopy and energy-dispersion analysis of the beryllium surface layer have been considered.     

Features of the magnetoplastic effect in a beryllium condensate

The effect of a weak dc magnetic field on inelastic characteristics of a magnesium-thermal beryllium condensate (99.95 wt % Be) has been studied. It has been shown that the magnetic field differently affects the defect subsystem of beryllium and, depending on sample treatment, leads to its hardening or softening. Based on an analysis of amplitude dependences of the internal friction and elastic moduli, the dislocation velocity after magnetic field exposure has been estimated. It has been shown that the magnetic aftereffect in Be is significantly stronger than the effect in situ.     

On the nature of the magnetoplastic effect in a beryllium condensate

The effect of a weak constant magnetic field on the temperature and amplitude dependences of the effective shear modulus, low-frequency internal friction, and the ratio of velocities of the dislocation motion in a magnetic field and without it in a beryllium condensate has been investigated. It has been shown that the simultaneous action of a constant magnetic field, mechanical stresses, and a variable temperature results in sign reversal of the magnetoplastic effect in beryllium. It has been found that the sign reversal of the magnetoplastic effect is accompanied by the sign reversal of the ratio of velocities of the dislocation motion, as well as by oscillations in the temperature dependence of this ratio. Possible mechanisms of manifestation of the magnetoplastic effect in beryllium have been discussed in terms of the results of the comprehensive analysis of the amplitude dependences of the studied characteristics.     

Diffusion of a low-soluble impurity in a solid matrix

An analytical expression for the concentration profile of a low-soluble diffusant in a sample is derived for a high-capacity diffusion source. The model is checked by determining the diffusion coefficient of yttrium in beryllium.     

Wavefunction and energy of the 1s22sns configuration in a beryllium atom

A new set of trial functions for 1s^22sns configurations in a beryllium atom is suggested. A Mathematica program based on the variational method is developed to calculate the wavefunctions and energies of 1s^22sns （n = 3 - 6） configurations in a beryllium atom. Non-relativistic energy, polarization correction and relativistic correction which include mass correction, one- and two-body Darwin corrections, spin-spin contact interaction and orbit-orbit interaction, are calculated respectively. The results are in good agreement with experimental data.