35 research outputs found

    In-flight calibration of the Cluster PEACE sensors

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    The Plasma Electron and Current Experiment (PEACE) instruments operate on all four of the Cluster spacecraft and measure the 3-D velocity distribution of electrons in the energy range from 0.59 eV to 26.4 keV during each spacecraft spin. Pitch angle distributions and moments of the velocity distribution are also produced. As the mission has progressed, the efficiency of the detectors has declined. Several factors may play a role in this decline such as exposure to radiation, high electron fluxes and spacecraft thruster firings. To account for these variations, continuous in-flight calibration work is essential. The purpose of this paper is to describe the PEACE calibration parameters, focussing in particular on those that vary over time, and to describe the methods which are used to determine their evolution

    QDB: A new database of plasma chemistries and reactions

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    One of the most challenging and recurring problems when modeling plasmas is the lack of data on the key atomic and molecular reactions that drive plasma processes. Even when there are data for some reactions, complete and validated datasets of chemistries are rarely available. This hinders research on plasma processes and curbs development of industrial applications. The QDB project aims to address this problem by providing a platform for provision, exchange, and validation of chemistry datasets. A new data model developed for QDB is presented. QDB collates published data on both electron scattering and heavy-particle reactions. These data are formed into reaction sets, which are then validated against experimental data where possible. This process produces both complete chemistry sets and identifies key reactions that are currently unreported in the literature. Gaps in the datasets can be filled using established theoretical methods. Initial validated chemistry sets for SF 6 /CF 4 /O 2 and SF 6 /CF 4 /N 2 /H 2 are presented as examples

    Перспективи використання випарних охолоджувачів в енергетичних системах

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    The conception of creating the multi-stage evaporated gas and liquid coolers on the basis of monoblock multichannel structures is developed. On the basis of the received experimental material the possibility analysis of such coolers is carried out.Разработана концепция создания многоступенчатых испарительных охладителей газов и жидкостей на основе моноблочных многоканальных насадочных структур. На основании полученного экспериментального материала выполнен анализ возможностей таких охладителей.Розроблена концепція створення багатоступінчастих випарних охолоджувачів газів і рідин на основі моноблокових багатоканальних насадкових структур. На підставі отриманого експериментального матеріалу виконано аналіз можливостей таких охолоджувачів

    Effect of working media on molded polymer materials

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    WATER-EMULSION SEPARATING COVERINGS FOR PRESS-MODES OF CASTING UNDER PRESSURE

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    The influence of surface-active materials and different additives on sedimentation resistance of emulsion on basis of heterochain polymers with high molecular mass used for coating of molds at casting under pressure is studied

    Progress towards the measurement of absolute elastic electron-molecular radical scattering cross sections

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    We report on our progress in developing a dedicated crossed beam apparatus, for the measurement of absolute cross sections for elastic scattering of electrons from molecular radicals. Features which are original to this apparatus will be highlighted, and a discussion of its current status and future developments provided
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