6,889 research outputs found

    A Wire Position Monitor System for the 1.3 GHZ Tesla-Style Cryomodule at the Fermilab New-Muon-Lab Accelerator

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    The first cryomodule for the beam test facility at the Fermilab New-Muon-Lab building is currently under RF commissioning. Among other diagnostics systems, the transverse position of the helium gas return pipe with the connected 1.3 GHz SRF accelerating cavities is measured along the ~15 m long module using a stretched-wire position monitoring system. An overview of the wire position monitor system technology is given, along with preliminary results taken at the initial module cool down, and during further testing. As the measurement system offers a high resolution, we also discuss options for use as a vibration detector.Comment: 4 pp. 15th International Conference on RF Superconductivity (SRF2011). 25-29 Jul 2011. Chicago, Illinois, US

    Classical R-matrix theory of dispersionless systems: I. (1+1)-dimension theory

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    A systematic way of construction of (1+1)-dimensional dispersionless integrable Hamiltonian systems is presented. The method is based on the classical R-matrix on Poisson algebras of formal Laurent series. Results are illustrated with the known and new (1+1)-dimensional dispersionless systems.Comment: 23 page

    Reactions at Polymer Interfaces: Transitions from Chemical to Diffusion-Control and Mixed Order Kinetics

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    We study reactions between end-functionalized chains at a polymer-polymer interface. For small chemical reactivities (the typical case) the number of diblocks formed, RtR_t, obeys 2nd order chemically controlled kinetics, RttR_t \sim t, until interfacial saturation. For high reactivities (e.g. radicals) a transition occurs at short times to 2nd order diffusion-controlled kinetics, with Rtt/lntR_t \sim t/\ln t for unentangled chains while t/lntt/\ln t and t1/2t^{1/2} regimes occur for entangled chains. Long time kinetics are 1st order and controlled by diffusion of the more dilute species to the interface: Rtt1/4R_t \sim t^{1/4} for unentangled cases, while Rtt1/4R_t \sim t^{1/4} and t1/8t^{1/8} regimes arise for entangled systems. The final 1st order regime is governed by center of gravity diffusion, Rtt1/2R_t \sim t^{1/2}.Comment: 11 pages, 3 figures, uses poliface.sty, minor changes, to appear in Europhysics Letter

    Gauge transformation and reciprocal link for (2+1)-dimensional integrable field systems

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    Appropriate restrictions of Lax operators which allows to construction of (2+1)-dimensional integrable field systems, coming from centrally extended algebra of pseudo-differential operators, are reviewed. The gauge transformation and the reciprocal link between three classes of Lax hierarchies are established.Comment: to appear in J. Nonl. Math. Phys., 12 page

    Symmetric Exclusion Process with a Localized Source

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    We investigate the growth of the total number of particles in a symmetric exclusion process driven by a localized source. The average total number of particles entering an initially empty system grows with time as t^{1/2} in one dimension, t/log(t) in two dimensions, and linearly in higher dimensions. In one and two dimensions, the leading asymptotic behaviors for the average total number of particles are independent on the intensity of the source. We also discuss fluctuations of the total number of particles and determine the asymptotic growth of the variance in one dimension.Comment: 7 pages; small corrections, references added, final versio
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