Vacuum requirements for the booster of NICA accelerator complex

This paper presents the results of a calculation of ¹⁹⁷Au³²⁺ ion beam losses as they interact with atoms and molecules of residual gas in the acceleration chamber of the booster vacuum system of the NICA accelerator complex [1].     

The influence of the annealing conditions on the photoluminescence of ion-implanted SiO2:Si nanosystem at additional phosphorus implantation

The influence of P ion doping on the photoluminescence (PL) of the system of nanocrystals in SiO₂ matrix (SiO₂:Si) both without annealing and after annealing at various temperatures (provided before and after additional P implantation) is investigated. The Si and P implantation was carried out with ion energies of 150 keV and doses Φ_Si=10¹⁷ cm⁻² and Φ_P=(0.1–300)×10¹⁴ cm⁻² (current density j3 μAcm⁻²). The system after Si implantation was formed at 1000°C and 1100°C (2 h). For the case of SiO₂:Si system as-implanted by P, the intensity of PL was drastically quenched, but partially retained. As for the step-by-step annealing (at progressively increased temperatures) carried out after P implantation, the sign and degree of doping effect change with annealing temperature. The possible mechanisms of these features are discussed.     

Thermal decomposition of bismuth stearates

Two bismuth salts, Bi₆O₄(OH)₄(C₁₇H₃₅COO)₆ and Bi₆O₄(OH)₄(C₁₇H₃₅COO)₆·nC₁₇H₃₅COOH, were synthesized. The thermogravimetry under quasi-isothermal conditions denotes the multi-step character of decomposition processes for both compounds. The thermogravimetry under linear heating was used for kinetic studies. Thermogravimetric data (obtained at different rates of linear heating) were processed with 'Netzsch Thermokinetics' computer program. Kinetic parameters were calculated only for the first decomposition step for both salts, the process is described by different nucleation equations (with and without autocatalysis). This revised version was published online in July 2006 with corrections to the Cover Date.     

Redox trends in terpyridine nickel complexes

A synthesis has been developed that allows the isolation of four-coordinate [(tpy)Ni-Br] (1, tpy = terpyridine) in high yield. Complex 1 has been structurally characterized, and the X-ray data reveal a square-planar geometry, unlike the known [(tpy')Ni-I] (tpy' = 4,4',4'-tri-tert-butyl-terpyridine) but similar to [(tpy)Ni-CH(3)]. In the solid-state, EPR spectroscopy indicates, however, that unlike [(tpy)Ni-CH(3)], the electronic structure of 1 is a metal-centered, not a ligand-centered radical. Density functional theory (DFT) analyses support this assignment. The preparation of 1 also facilitated the analysis of the redox potentials of a series of terpyridine nickel derivatives. It was found that the overall ligand sphere (one vs two coordinated terpyridine ligands) plays more of a role in determining the redox potentials of these derivatives than do the formal oxidation states of the nickel ions in the solution phase.     

Development of Software for Simulating and Analyzing the Dynamics of Charged-Particle Beams in Synchrotrons and Beam Lines

The paper considers software for the simulation and analysis of transverse dynamics of charged particle beams in synchrotrons and beam lines. It calculates the transverse beam dynamics in synchrotrons and beam lines based on the linear model, the structural functions of synchrotrons and beam lines, the beam acceptance and emittance, and the orbit correction. The software is capable of calculating the orbit-correction quality distributions and reconstructing the transport matrix parameters from the response matrices.     

Graphene oxide supported tin dioxide: synthetic approaches and electrochemical characterization as anodes for lithium- and sodium-ion batteries

The review addresses synthetic approaches to composite materials based on graphene oxide and nano tin dioxide and their electrochemical properties as anodes for lithium- and sodiumion batteries. The introduction of a carbon matrix into the composite material improves the electrochemical characteristics of the anodes. In most methods, the synthesis of graphene oxide–tin dioxide composites is based on the use of tin(II,IV) chlorides as the starting compounds, and the most efficient electrode materials were obtained by the hydrothermal or solvothermal routes. Thermal processing is much more economic than the gas phase deposition protocols but requires heating of a large volume of dilute tin oxide dispersions in an autoclave. Mechanochemistry (ball milling) is also economically unfavorable for the synthesis of composite materials. In addition, large volumes of acidic wastes that should be neutralized and safely discarded are formed when tin chlorides are used. An alternative environmentally friendly technique based on the use of aqueous peroxide solutions can be applied for the production of efficient anode materials based on graphene oxide and tin dioxide. This process does not involve acidic wastes, uses hydrogen peroxide and ethanol as reagents, and accomplishes film deposition (coating) at room temperature. Final thermal treatment is required only for the active material, which minimizes energy expenses and equipment costs.     

Correctors’ Magnets for the NICA Booster and Collider

Physics of Particles and Nuclei Letters - The NICA accelerator complex will consist of two injector chains, a new 600 MeV/u superconducting booster synchrotron, the existing superconducting...     

PREPARATION AND CRYSTAL STRUCTURE OF THE TANTALUM BROMIDE CLUSTER COMPLEX [Li(diglyme)2]2[Ta6Br18]

Journal of Structural Chemistry - Extracting the reaction product of Ta, Br2, and LiBr (720 °C, 48 h, mole ratio 1.5:1.75:1.0) with diglyme yields crystals of complex...