Plasma processing of closed nuclear fuel cycle waste

В работе предложен плазменный метод переработки отходов замкнутого ядерного топливного цикла в виде водно-солеорганической композиции. Этот метод имеет несколько преимуществ и позволяет безопасно перерабатывать такой материал. Определен оптимальный состав для утилизации данного отхода в плазме. Равновесные составы показали, что в процессе плазменной обработки образуются N[2], CO[2], H[2]O, а также FeCl[3] и Fe[2]O[3 в конденсированной фазе. Отсутствие сажи является показателем того, что процесс переработки является экологически безопасным.The work proposed the plasma method of processing closed nuclear fuel cycle wastes in the form of a water-salt-organic composition. This method has several advantages and allows recycling such material safely. The optimal composition for recycling in plasma was determined. Equilibrium compositions showed that in the process of plasma processing N[2], CO[2], H[2]O and also FeCl[3] и Fe[2]O[3] in the condensed phase were formed. Lack of soot is an indicator that the recycling process is environmentally safe

First In-Orbit Experience of TerraSAR-X Flight Dynamics Operations

TerraSAR-X is an advanced synthetic aperture radar satellite system for scientific and commercial applications that is realized in a public-private partnership between the German Aerospace Center (DLR) and the Astrium GmbH. TerraSAR-X was launched at June 15, 2007 on top of a Russian DNEPR-1 rocket into a 514 km sun-synchronous dusk-dawn orbit with an 11-day repeat cycle and will be operated for a period of at least 5 years during which it will provide high resolution SAR-data in the X-band. Due to the objectives of the interferometric campaigns the satellite has to comply to tight orbit control requirements, which are formulated in the form of a 250 m toroidal tube around a pre-flight determined reference trajectory (see [1] for details). The acquisition of the reference orbit was one of the main and key activities during the Launch and Early Orbit Phase (LEOP) and had to compensate for both injection errors and spacecraft safe mode attitude control thruster activities. The paper summarizes the activities of GSOC flight dynamics team during both LEOP and early Commissioning Phase, where the main tasks have been 1) the first-acquisition support via angle-tracking and GPS-based orbit determination, 2) maneuver planning for target orbit acquisition and maintenance, and 3) precise orbit and attitude determination for SAR processing support. Furthermore, a presentation on the achieved results and encountered problems will be addressed

Parton interactions in the Bjorken limit of QCD

We consider the Bjorken limit in the framework of the effective action approach and discuss its similarities to the Regge limit. The proposed effective action allows for a rather simple calculation of the known evolution kernels. We represent the result in terms of two-parton interaction operators involving gluon and quark operators depending on light-ray position and helicity and analyze their symmetry properties.Comment: 32 pages LaTex, 4 eps-figures, comments added, minor correction

Dissociative recombination and electron-impact de-excitation in CH photon emission under ITER divertor-relevant plasma conditions

For understanding carbon erosion and redeposition in nuclear fusion devices, it is important to understand the transport and chemical break-up of hydrocarbon molecules in edge plasmas, often diagnosed by emission of the CH A^2\Delta - X^2\Pi Ger\"o band around 430 nm. The CH A-level can be excited either by electron-impact or by dissociative recombination (D.R.) of hydrocarbon ions. These processes were included in the 3D Monte Carlo impurity transport code ERO. A series of methane injection experiments was performed in the high-density, low-temperature linear plasma generator Pilot-PSI, and simulated emission intensity profiles were benchmarked against these experiments. It was confirmed that excitation by D.R. dominates at T_e < 1.5 eV. The results indicate that the fraction of D.R. events that lead to a CH radical in the A-level and consequent photon emission is at least 10%. Additionally, quenching of the excited CH radicals by electron impact de-excitation was included in the modeling. This quenching is shown to be significant: depending on the electron density, it reduces the effective CH emission by a factor of 1.4 at n_e=1.3*10^20 m^-3, to 2.8 at n_e=9.3*10^20 m^-3. Its inclusion significantly improved agreement between experiment and modeling

The BFKL Pomeron in 2+1 Dimensional QCD

We investigate the high-energy scattering in the spontaneously broken Yang - Mills gauge theory in 2+1 space--time dimensions and present the exact solution of the leading $\ln s$ BFKL equation. The solution is constructed in terms of special functions using the earlier results of two of us (L.N.L. and L.S.). The analytic properties of the $t$-channel partial wave as functions of the angular momentum and momentum transfer have been studied. We find in the angular momentum plane: (i) a Regge pole whose trajectory has an intercept larger than 1 and (ii) a fixed cut with the rightmost singularity located at $j=1$. The massive Yang - Mills theory can be considered as a theoretical model for the (non-perturbative) Pomeron. We study the main structure and property of the solution including the Pomeron trajectory at momentum transfer different from zero. The relation to the results of M. Li and C-I. Tan for the massless case is discussed.Comment: 28 pages LATEX, 3 EPS figures include

Production of electroweak bosons in e+e- annihilation at high energies

Production of electroweak bosons in e+e- annihilation into quarks and into leptons at energies much greater than 100 Gev is considered. We account for double-logarithmic contributions to all orders in electroweak couplings. It is assumed that the bosons are emitted in the multi-Regge kinematics. The explicit expressions for the scattering amplitudes of the process are obtained. It is shown that the cross sections of the photon and Z production have the identical energy dependence and asymptotically their ratio depends only on the Weinberg angle whereas the energy dependence of the cross section of the W production is suppressed by factor s^{-0.4} compared to them.Comment: Revtex4, 16 pages, 7 figures, 2 table

On the forward-backward charge asymmetry in e+e- -annihilation into hadrons at high energies

The forward-backward asymmetry in e+ e- annihilation into a quark-antiquark pair is considered in the double-logarithmic approximation at energies much higher than the masses of the weak bosons. It is shown that after accounting to all orders for the exchange of virtual photons and W, Z -bosons one is lead to the following effect (asymmetry): quarks with positive electric charge (e.g. u, \bar{d}) tend to move in the e+ - direction whereas quarks with negative charges (e.g. d, \bar{u}) tend to move in the e- - direction. The value of the asymmetry grows with increasing energy when the produced quarks are within a cone with opening angle, in the cmf, \theta_0\sim 2M_Z/\sqrt{s} around the e+e- -beam. Outside this cone, at \theta_0 << \theta << 1, the asymmetry is inversely proportional to \theta .Comment: 17 Pages, 2 Tables, 4 Figures. Hadronization effects to the asymmetry are considered with more detail

Resummation of double logarithms in electroweak high energy processes

At future linear $e^+e^-$ collider experiments in the TeV range, Sudakov double logarithms originating from massive boson exchange can lead to significant corrections to the cross sections of the observable processes. These effects are important for the high precision objectives of the Next Linear Collider. We use the infrared evolution equation, based on a gauge invariant dispersive method, to obtain double logarithmic asymptotics of scattering amplitudes and discuss how it can be applied, in the case of broken gauge symmetry, to the Standard Model of electroweak processes. We discuss the double logarithmic effects to both non-radiative processes and to processes accompanied by soft gauge boson emission. In all cases the Sudakov double logarithms are found to exponentiate. We also discuss double logarithmic effects of a non-Sudakov type which appear in Regge-like processes.Comment: 26 pages, 3 figures, Latex2