Extraction of the carbon ion beam from the U-70 accelerator into beamline 4a using a bent single crystal

A beam of six-charged carbon ions with an energy of 24.8 GeV/nucleon is extracted from the U-70 synchrotron by means of a silicon crystal bent through 85 mrad. A total of 200000 particles are observed in beamline 4a upon forcing 10⁹ circulating ions to the crystal. The geometrical parameters, timing structure, and composition of the beam have been measured. It has been shown for the first time that, using a bent single crystal, an ion beam with required parameters can be extracted from the accelerator ring and formed for regular use in physics experiments.     

Li collection experiments on T-11M and T-10 in framework of Li closed loop concept

The concept of a steady state tokamak with plasma facing components (PFC) on the basis of liquid lithium circulation demands the decision of three tasks: lithium injection to the plasma, lithium ions collection before their deposition on the vacuum vessel and lithium returning to the injection zone. Main subject of paper is the investigations of Li collection by different types of limiters intersected the scrape-of-layer (SOL) in T-10 and T-11M tokamaks. For finding solution for this problem in T-11M and T-10, experiments have been applied with Li-, C-rail limiters and ring SS R-limiter-collector (T-11M). The efficiency of Li collection by limiters in T-11M and T-10 tokamaks was investigated by post mortem sample–witness analysis and (T-11M) by the use of the mobile graphite probe (limiter) as a recombination target in the stream of lithium ions. The characteristic depth of lithium penetration in the SOL area of T-11M is about 2 cm and 4 cm in SOL of T-10. The quantitative analysis of the sample–witnesses located on T-11M limiters showed that 60 ± 20% of the lithium injected during plasma operating of T-11M had been collected by limiters. It confirms an opportunity of the lithium ions collection by limiters in tokamak SOL.     

Effect of heat treatment on the structure of high-nitrogen austenitic corrosion-resistant 04Kh22AG17N8M2F and 07Kh20AG9N8MF steels

The structures of high-strength austenitic 04Kh22AG17N8M2F and 07Kh20AG9N8MF steels are studied after various heat-treatment conditions, and the relation between these structures and the mechanical and chemical properties of these steels is analyzed. The phase compositions of the steels, the morphology of phases, the fine structure of austenite, and the mechanism of its decomposition upon heating are investigated by X-ray diffraction and transmission electron microscopy. The homogeneous decomposition of the supersaturated γ solid solution in the 04Kh22AG17N8M2F steel at 500 °C is shown to be accompanied by the formation of the CrN nitride, which is isomorphic to the matrix, and to increase the strength and elastic stresses in the austenite, decreasing the stress corrosion cracking (SCC) resistance of the steel. Heating at 800 °C facilitates stress relaxation and increases the SCC resistance of the steel.     

Population approach to environmental problems

A multilayer population is defined as a collection of sets of homogeneous elements ordered by several parameters. A multilayer population is an applied generalization of a branching process. The main features of multilayer populations are discussed.Translated from Kibernetika i Sistemnyi Analiz, No. 5, pp. 71–80, September–October, 1992.     

Alkaline hydrolysis of nitrile groups in hydrazided nitron fibre

Conclusions The process of alkaline hydrolysis of nitrile groups in hydrazided Nitron fibre has been studied. It has been shown that introduction of hydrazidine groups into the polymer chain catalyzes the alkaline hydrolysis process because of a change in the basicity of the polymer chain.A cation-exchange VION KN-1 fibre has been prepared with higher physico-mechanical properties, which still retains satisfactory sorptive properties.Translated from Khimicheskie Volokna, No. 3, pp. 7–8, May–June, 1988.     

Optimization of the preparation of VION chemisorptive fibre containing carboxyl groups

Conclusions The sorptive properties of VION fibre with carboxyl groups have been studied. It has been shown that at an SEC over 3.5 meq/g no corresponding increase in degree of absorption of ammonia by the fibrous sorbent takes place.Optimization of the conditions for preparing the weak acid VION fibre at an assigned SEC selected from the results of sorption measurements has been carried out.Translated from Khimicheskie Volokna, No. 2, pp. 7–8, March–April, 1989.     

Investigation of the gas-dynamic characteristics of hollow semipermeable fibres

Conclusions A scheme of a laboratory set-up for measuring the gas-dynamic resistance of hollow fibre channels over a wide range of temperatures and pressures has been described.A procedure for performing experiments and the results of experimental measurements of the flow rate of nitrogen, ammonia, argon, hydrogen, helium, and methane through the channels of polypropylene fibres from 20 to 0.2 m in length at 293°K and a pressure drop from 0.098 to 2.124 MPa have been presented.It has been found that the flow rate of the investigated gases increases regularly on increasing the pressure drop and decreases with increase in the length of the hollow fibre specimen. For hydrogen, helium, nitrogen, and argon, under otherwise equal conditions, flow rate decreases with increase in molecular weight of the gas. For ammonia and methane, a deviation from this relationship is observed, since the flow rate of these gases exceeds that of helium.Translated from Khimicheskie Volokna, No. 6, pp. 13–14, November–December, 1985.     

Current-voltage characteristics of Si/Si1 − x Ge x heterodiodes fabricated by direct bonding

We have studied the current-voltage (I–U) characteristics of Si/Si_{1 ? x} Ge _x (0.02 < x < 0.15) heterodiodes fabricated by direct bonding of (111)-oriented n-type single crystal silicon wafers with p-type Si_{1 ? x} Ge _x wafers of the same orientation containing 2–15 at % Ge. An increase in the germanium concentration N _Ge in Si_{1 ? x} Ge _x crystals is accompanied by a growth in the density of crystal lattice defects, which leads to a decrease in the minority carrier lifetime in the base of the heterodiode and an increase in the recombination component of the forward current and in the differential resistance (slope) of the I–U curve. However, for all samples with N _Ge ≤ 15 at %, the I–U curves of Si/Si_{1 ? x} Ge _x heterodiodes are satisfactory in the entire range of current densities (1 mA/cm²–200 A/cm²). This result shows good prospects for using direct bonding technology in the fabrication of Si/Si_{1 ? x} Ge _x heterostructures.     

The development of new metallurgical materials and technologies. Part 1

Work by researchers at the Russian Academy of Sciences on new materials (metals and ceramics) and new technologies is reviewed. The topics include new high-strength corrosion-resistant nitrogen steels; high-temperature light alloys and composites based on intermetallics; modifiers for wheel steels; complex ferroalloys containing V, Cr, and Ni; anticorrosive protective coatings based on ultrafine Zn powders; catalytic converters for vehicle exhaust gases; magnetically hard materials with high temperature–time stability and excellent mechanical characteristics; nanostructured stents for endovascular operations; and corrosionand wear-resistant coatings and corresponding methods of plasma application. Methods have been developed for longitudinal rolling with shear deformation to improve the properties of the rolled product; recycling of oily scale; monitoring of the wear of the refractory lining at any point of the blast-furnace hearth; and monitoring of the content of inclusions in rail steel. Technologies have been developed for special electroproduction of steel for the power industry; synthesis of massive monocrystalline samples of transition-metal nitrides and nanopowders of W, Pt, and Ti and their carbides and nitrides; the processing of leucoxene concentrates from the Yareg Basin; the production of titanium implants with porous coatings; ferrous and nonferrous metal shot and powder; ultrafine Zn powder; recycling of metallurgical wastes with the extraction of Zn, Sb, Sn, and Fe; the production of sintered nanocrystalline Ta powder for capacitors; the processing of molybdenum-bearing sulfide material to obtain rare-earth metals, MoO₃, and CaMoO₄; and the utilization of sulfur dioxide. Injection units and technologies for their use have been developed, as well as high-speed systems for the plasma application of metals on surfaces including paint coatings, plastics, and cardboard. Data have been obtained regarding the thermodynamic functions of the solution of oxygen in Fe-based melts and the reactions of elements dissolved in such melts (Cr, Mn, Nb, V, Si, B, C, Ti, Zr, Al) with oxygen.