26,706 research outputs found

    Antenna Technology for QUASAT application

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    A hybrid growth version of the advanced Sunflower, or precision deployable, antenna was adopted as the configuration proposed for the QUASAT very long baseline interferometry mission. The antenna consists of rigid panels of graphite-epoxy facesheets covering aluminum honeycomb sandwich. The six main folding panels are hinged to a cantilevered support ring attached to the periphery of the center section. Six pairs of intermediate panels are located between these panels and are hinged to each other and to the main panels. The flight configuration, antenna weight, a mass properties, frequency, and contour tolerance are discussed. The advantages of the solid antenna surface cover an all-mesh contour are examined

    6D Muon Ionization Cooling with an Inverse Cyclotron

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    A large admittance sector cyclotron filled with LiH wedges surrounded by helium or hydrogen gas is explored. Muons are cooled as they spiral adiabatically into a central swarm. As momentum approaches zero, the momentum spread also approaches zero. Long bunch trains coalesce. Energy loss is used to inject the muons into the outer rim of the cyclotron. The density of material in the cyclotron decreases adiabatically with radius. The sector cyclotron magnetic fields are transformed into an azimuthally symmetric magnetic bottle in the center. Helium gas is used to inhibit muonium formation by positive muons. Deuterium gas is used to allow captured negative muons to escape via the muon catalyzed fusion process. The presence of ionized gas in the center may automatically neutralize space charge. When a bunch train has coalesced into a central swarm, it is ejected axially with an electric kicker pulse.Comment: Five pages. LaTeX, three postscript figure files. To appear in the AIP Conference Proceedings for COOL05: International Workshop on Beam Cooling, Galena, IL, 18-23 Sept. 200

    A Pulsed Synchrotron for Muon Acceleration at a Neutrino Factory

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    A 4600 Hz pulsed synchrotron is considered as a means of accelerating cool muons with superconducting RF cavities from 4 to 20 GeV/c for a neutrino factory. Eddy current losses are held to less than a megawatt by the low machine duty cycle plus 100 micron thick grain oriented silicon steel laminations and 250 micron diameter copper wires. Combined function magnets with 20 T/m gradients alternating within single magnets form the lattice. Muon survival is 83%.Comment: 4 pages, 1 figures, LaTeX, 5th International Workshop on Neutrino Factories and Superbeams (NuFact 03), 5-11 Jun 2003, New Yor

    Interdisciplinary (retail) research: The business of geography and the geography of business

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    NoAt the 2005 British Academy of Management conference several well-known economic geographers, including Neil Wrigley, Gordon Clark, and Susan Christopherson, called for management researchers to engage with economic geographers on interrelated geographical and managerial issues in the study of (retail) firms. In this commentary we reflect upon the present geography -management interface.We begin by considering the term `interdisciplinary research' and its relationship to any management - geography interface. This is followed by a context-specific discussion of international retailing and the role of research on the retail transnational corporation (TNC) in developing an interdisciplinary agenda. This commentary represents an initial more business and management focused response to the call from geography academics for more/better interdisciplinary research at the geography - management interface
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