Synthesis and structure of phenylbismuth bis(chloroacetate)

Crystals of phenylbismuth bis(chloroacetate) were synthesized by the reaction of triphenylbismuth with chloroacetic acid. Tridentate chelate-bridging chloroacetate ligands are bonded to neighboring molecules through the O atoms to form polymer chains. The Bi-O distances are equal to 2.36(1), 2.55(1), 2.78(1) and 2.30(1), 2.67(1), 2.85(2) Å. the length of the Bi-C bond is 2.26(2) Å.     

Malliavin Calculus Approach to Statistical Inference for Lévy Driven SDE’s

By means of the Malliavin calculus, integral representations for the likelihood function and for the derivative of the log-likelihood function are given for a model based on discrete time observations of the solution to equation dX _t = a _θ (X _t )dt + dZ _t with a Lévy process Z. Using these representations, regularity of the statistical experiment and the Cramer-Rao inequality are proved.     

Conductivity of nonstoichiometric fluorides LnF2+x (Ln = Sm,Eu, Yb)

Nonstoichiometric fluorides LnF_2+x (Ln = Sm, Eu, Yb) were synthesized by reduction of trifluorides with the above rare-earth elements. The resulting phases were identified by chemical and X-ray phase analyses, their composition and structure were determined, and their lattice constants were found. The ac bridge method at a frequency of 70 kHz was used to study the conductivity of the synthesized compounds and starting trifluorides in the temperature range 773–298 K. The temperature dependence of the conductivity of these compounds is satisfactorily approximated by the Arrhenius-Frenkel equation. A kink is observed on the plots of the electrical conductivity against temperature for all compounds. With decreasing content of fluorine, this kink shifts to higher temperatures. The highest conductivity is observed for the phases with low crystal packing density. With increasing content of fluorine, the conductivity of all nonstoichiometric phases not belonging to substitution solid solutions approaches the conductivity of the corresponding trifluorides.     

Macroscopic Isotope Separation of 13C by a CO2 Laser

By photochemical dissociation of the rare carbon isotope component of CHClF₂ by means of a CO₂ laser with an average power of 150 W, Q-switched at 10 kHz, we have demonstrated the separation of more than 1 mol of ¹³C, enriched to 50% (2 mol of total carbon). It is contained in about 1 mol (101 g) of the product C₂F₄. The total throughput of the starting material was 29 kg. The experiment was run day and night for 2 weeks, almost only controlled by a computer. We obtained production rates of 5 mmol/h, corresponding to about 0.5 kg ¹³C per year.     

Electron-beam charging of dielectrics preirradiated with moderate-energy ions and electrons

The effects of charging of dielectric targets irradiated with moderate-energy electrons in a scanning electron microscope are examined. Considerable differences in the kinetics of charging of the reference samples and the samples preirradiated with ions and electrons are reported. These differences are attributed to the processes of radiation-induced defect formation in Al₂O₃ (sapphire) and SiO₂ that are, however, dissimilar in nature. The contributions of surface structure modification and changes in the electrophysical parameters of the surface (specifically, the charge spreading effect) are revealed. Critical doses of irradiation with Ar⁺ ions and electrons inducing active defect formation in dielectric targets and critical values of internal charge fields producing a significant contribution to the temporal parameters of Al₂O₃ and SiO₂ charging are determined.     

Development of Hybrid Transport Systems for Delivering Cryogenic Fusion Targets Into Focus of High-Power Laser System or ICF Reactor

We present our results on utilization of the quantum levitation effect for HTSC samples (superconducting ceramics based on YBa₂Cu₃O_7?x and SuperOx J-PI-12-20Ag-20Cu superconducting tapes) in magnetic fields of different configurations with respect to developing special carriers for hybrid systems of noncontact transport of cryogenic targets in ICF experiments. We implement the obtained results for developing and engineering of “HTSC-MAGLEV” delivery system to minimize the risk for damage of the fuel layer at the target acceleration and during target injection into the center of the ICF reaction chamber.     

DC-60 heavy ion cyclotron complex: The first beams and project parameters

The construction of the DC-60 Heavy Ion Cyclotron for the Interdisciplinary Scientific Research Complex (ISRC) in Astana started in early 2004. The cyclotron was manufactured and tested at the Flerov Laboratory of Nuclear Reactions (FLNR) in Dubna. The main units were delivered to Astana and assembled in the ISRC building in the summer of 2006. The cyclotron was turned on in September, 2006. The first heavy ion beams in the whole A/Z and energy ranges were accelerated and extracted in December, 2006. The complex, based on the DC-60 cyclotron, is intended for applied and fundamental research using accelerated heavy ion beams ranging from Carbon to Xenon with energies in the range of 0.34–1.77 MeV/nucleon, as well as for experiments on the channel of low energy ion beams, where the ion extraction voltage supplied by the ECR source reaches 25 kV. The energy variation of the accelerated ions is accomplished by changing the ion charge. The possibility of smoothly tuning the ion energy by ±30% of its nominal value can be seen by changing the cyclotron magnetic field. Within the framework of commissioning the DC-60 cyclotron, a number of experiments were carried out with accelerating charged particle beams in the main points of the working diagram