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
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
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
We study reactions between end-functionalized chains at a polymer-polymer
interface. For small chemical reactivities (the typical case) the number of
diblocks formed, , obeys 2nd order chemically controlled kinetics, , until interfacial saturation. For high reactivities (e.g. radicals) a
transition occurs at short times to 2nd order diffusion-controlled kinetics,
with for unentangled chains while and
regimes occur for entangled chains. Long time kinetics are 1st order and
controlled by diffusion of the more dilute species to the interface: for unentangled cases, while and regimes
arise for entangled systems. The final 1st order regime is governed by center
of gravity diffusion, .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
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
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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