7,219 research outputs found
Leading Twist Amplitudes for Exclusive Neutrino Interactions in the Deeply Virtual Limit
Neutrino scattering on nucleons in the regime of deeply virtual kinematics is
studied both in the charged and the neutral electroweak sectors using a
formalism developed by Blumlein, Robaschik, Geyer and Collaborators for the
analysis of the Virtual Compton amplitude in the generalized Bjorken region. We
discuss the structure of the leading twist amplitudes of the process.Comment: 14 pages, 1 fig revised final version to appear in Phys. Rev.
The NSNS High Energy Beam Transport Line
In the National Spallation Neutron Source (NSNS) design, a 180 meter long
transport line connects the 1 GeV linac to an accumulator ring. The linac beam
has a current of 28 mA, pulse length of 1 ms, and 60 Hz rep rate. The high
energy transport line consists of sixteen 60 degrees FODO cells, and
accommodates a 90 degrees achromatic bend, an energy compressor, collimators,
part of injection system, and enough diagnostic devices to measure the beam
quality before injection. To reduce the uncontrolled beam losses, this line has
nine beam halo scrapers and very tight tolerances on both transverse and
longitudinal beam dynamics under space charge conditions. The design of this
line is presented.Comment: 3 pages, transfer line desig
An identification procedure of multi-input Wiener models for the distortion analysis of nonlinear circuits
In this contribution, a system identification procedure of a two-input Wiener
model suitable for the analysis of the disturbance behavior of integrated
nonlinear circuits is presented. The identified block model is comprised of
two linear dynamic and one static nonlinear block, which are determined using
an parameterized approach. In order to characterize the linear blocks, an
correlation analysis using a white noise input in combination with a model
reduction scheme is adopted. After having characterized the linear blocks,
from the output spectrum under single tone excitation at each input a linear
set of equations will be set up, whose solution gives the coefficients of the
nonlinear block. By this data based black box approach, the distortion
behavior of a nonlinear circuit under the influence of an interfering signal
at an arbitrary input port can be determined. Such an interfering signal can
be, for example, an electromagnetic interference signal which conductively
couples into the port of consideration
Mott physics, sign structure, ground state wavefunction, and high-Tc superconductivity
In this article I give a pedagogical illustration of why the essential
problem of high-Tc superconductivity in the cuprates is about how an
antiferromagnetically ordered state can be turned into a short-range state by
doping. I will start with half-filling where the antiferromagnetic ground state
is accurately described by the Liang-Doucot-Anderson (LDA) wavefunction. Here
the effect of the Fermi statistics becomes completely irrelevant due to the no
double occupancy constraint. Upon doping, the statistical signs reemerge,
albeit much reduced as compared to the original Fermi statistical signs. By
precisely incorporating this altered statistical sign structure at finite
doping, the LDA ground state can be recast into a short-range antiferromagnetic
state. Superconducting phase coherence arises after the spin correlations
become short-ranged, and the superconducting phase transition is controlled by
spin excitations. I will stress that the pseudogap phenomenon naturally emerges
as a crossover between the antiferromagnetic and superconducting phases. As a
characteristic of non Fermi liquid, the mutual statistical interaction between
the spin and charge degrees of freedom will reach a maximum in a
high-temperature "strange metal phase" of the doped Mott insulator.Comment: 12 pages, 12 figure
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Performance and measurements of the AGS and Booster beams
Analyses of Hot Gas Stream Cleanup (HGSC) ashes and descriptions of filter performance were made to address the problems with filter operation that are apparently linked to the collected ash. This task is designed to generate data base of the key properties of ashes collected from operating advanced particle filters and to relate these ash properties to the operation and performance of these filters. Activities including initial formatting of the data base and entry, modification of the permeability model, and initial design of a high-temperature test device for measuring uncompacted bulk porosity of ash aggregates (indicator of relative cohesivity of the ash, filter cake porosity/permeability). Chemical analyses of hopper and filter cake ashes from Tidd showed that the consolidation degree could not be accounted for by condensation/adsorption from the flue gas; the mechanism is likely physical rearrangement of the ash particles
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Fundamentals: Longitudinal motion
This paper discusses the following topics on synchrotrons: Dynamics of Synchrotron; Acceleration Cavity; Beam Manipulation and Beam Control; and High Intensity Effects. 21 refs., 26 figs. (LSP
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Ultra-High Intensity Proton Accelerators and their Applications
The science and technology of proton accelerators have progressed considerably in the past three decades. Three to four orders of magnitude increase in both peak intensity and average flux have made it possible to construct high intensity proton accelerators for modern applications, such as: spallation neutron sources, kaon factory, accelerator production of tritium, energy amplifier and muon collider drivers. The accelerator design focus switched over from intensity for synchrotrons, to brightness for colliders to halos for spallation sources. An overview of this tremendous progress in both accelerator science and technology is presented, with special emphasis on the new challenges of accelerator physics issues such as: H(-) injection, halo formation and reduction of losses
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