Time-projection chamber for the PEN experiment

The PEN collaboration carries out a precision measurement of the ??⁺ ?? e ⁺?? decay branching ratio at the Paul Scherrer Institute (PSI, Switzerland). A special mini time-projection chamber (mTPC) has been developed for registration of particles in the pion beam. The chamber contains 14 × 10^?3 g/cm² of matter on the particle path. The chamber was successfully used during one-year-long run. Design and characteristics of the mTPC are described.     

Electrochemical Arylation of N-Containing Chelate and Macrocyclic Complexes of Transition Metals with the Aid of Diphenyliodonium Salts

A new method of electrochemical arylation of complexes of transition metals (Fe, Co, Ni) with N-containing chelate and macrocyclic (dimethylglyoximate, porphyrin, etc.) ligands employs diphenyliodonium salts as arylating agents and permits the synthesis of compounds containing functional groups that are easily reduceable or sensitive to the action of organometallic compounds. A homogeneous redox catalysis (mediator 1,5-dinitroanthraquinone-9,10) reduces the reaction potential to –0.45 V (Ag/AgCl/KCl), thus substantially decreasing the contribution of side processes.     

Site specific effects in alloy surface reactivity probed by Li ions

We investigated site specific reactivity of the α-Cu-Al(17 at.%)(1 0 0) alloy surface versus that of Al and Cu by measuring neutralisation of Li⁺ ions. Experiments show that Li⁺ neutralisation on the α-CuAl(1 0 0) alloy surface does not occur efficiently on Al and is somewhat more efficient on Cu as compared to a pure Cu sample, indicating depletion of electron density on Al and transfer to neighboring Cu. It can thus be concluded that Cu sites in presence of Al are more reactive in the sense that processes involving electron capture from the surface would proceed more efficiently on these.     

Surface action of a heat pulse in a tangential flow

The three-dimensional unsteady problem of the action of a localized radiation pulse on an aluminum plate of finite thickness in a tangential airflow is solved on the basis of the Euler equations in the gas phase and the heat conduction equation in the solid. The process is accompanied by the intense evaporation of plate material and the subsequent (after the action of the radiation pulse ceases) intense condensation of aluminum vapor and condensate particles on the surface. The problem is solved on the assumption that the surface is not screened by its disintegration products and the processes associated with the self-radiation of the gas are disregarded. Heat pulses of intensityq=10⁶−10⁷ W/cm² and durationt _i ≈10⁻⁴ sec are investigated. Various regimes are calculated and the effect of the governing parameters on the impulse transmitted to the surface and ablation of the target material is established. A nontraditional approach, based on the idea of statistical modeling of the motion of an inviscid non-heat-conducting gas at the kinetic level, is used for solving the gas dynamic problem. The application of the approach in question to the solution of problems of this class is justified. Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.1, pp. 139–146, January–February, 1994.     

Solid-Liquid-Phase Equilibria in the System KCl?MgCl2?H2O at Elevated Temperatures. I. The Binary System MgCl2?H2O at 130–250°C

Experimental studies of the solid-liquid-phase equilibria of the system MgCl₂? H₂O within a temperature range of 130°C to 250°C are presented.     

Arguments in favour of a program of seismic detection of gravity wave bursts

Summary The possibility is shown of selecting gravity wave perturbations in earth crust block in the seismic-noise background due to far local sources. It is shown that the utilization of different space-time ?colourations? of gravity wave and noise perturbations makes it possible, in principle, to extract the signal in the background of noise of exceeding intensity.     

Current Status and Objectives of Modernizing the Engineering,Physical, and Energy Infrastructure of the SFT Facility for the Implementation of the Ignitor Project

Physics of Atomic Nuclei - The Ignitor tokamak nuclear fusion research project is one of the most ambitious initiatives undertaken under the long-term scientific cooperation program between the...