5,011 research outputs found
A High Current Proton Linac with 352 MHz SC Cavities
A proposal for a 10-120 mA proton linac employing superconducting
beta-graded, CERN type, four cell cavities at 352 MHz is presented. The high
energy part (100 MeV-1 GeV) of the machine is split in three beta-graded
sections, and transverse focusing is provided via a periodic doublet array. All
the parameters, like power in the couplers and accelerating fields in the
cavities, are within the state of the art, achieved in operating machines. A
first stage of operation at 30 mA beam current is proposed, while the upgrade
of the machine to 120 mA operation can be obtained increasing the number of
klystrons and couplers per cavity. The additional coupler ports, up to four,
will be integrated in the cavity design. Preliminary calculations indicate that
beam transport is feasible, given the wide aperture of the 352 MHz structures.
A capital cost of less than 100 M for the 120
mA extension, has been estimated for the superconducting high energy section
(100 MeV-1 GeV). The high efficiency of the proposed machine, reaching 50% at
15 mA, makes it a good candidate for proposed nuclear waste incineration
facilities and Energy Amplifier studies.Comment: 9 Pages, 4 figures, LaTeX2e, html version found from
http://hptesla.mi.infn.it/~pierini/publication_list.html . To Appear in the
Proceedings of the 1996 LINAC Conference, Geneve, August 26-30 199
Entanglement, Superselection Rules and Supersymmetric Quantum Mechanics
In this paper we show that the energy eigenstates of supersymmetric quantum
mechanics (SUSYQM) with non definite "fermion" number are entangled states.
They are "physical states" of the model provided that observables with odd
number of spin variables are allowed in the theory like it happens in the
Jaynes-Cummings model. Those states generalize the so called "spin spring"
states of the Jaynes-Cummings model which have played an important role in the
study of entanglement.Comment: 2 words added in the title, a section (IV) added in the text, a new
author joined the projec
Some considerations to carry out a composite indicator for ordinal data
Composite indicators (CIs) are important and useful tools in many elds to assess, compare and rank performances, development stage, quality and many other different targets. CIs are an overall measure of a multidimensional, not directly observable, concept and are obtained by means of a set of manifest variables (elementary indicators) that contribute to dene the overall measure. In this paper, some matters regarding methods to build CIs are reviewed, assuming elementary indicators are ordinal and quantication is necessary to convert observed data into a numerical form. Scoring methods, aggregating functions and weighting systems are considered. In particular, a scoring method based on the observed distribution or the use of dissimilarity indices for quantication together with the Kendall-T association or a heterogeneity measure for weighting are suggested. Some of the reviewed procedures are compared using students' satisfaction data. \ua9 Universit\ue0 del Salento
Fractal Geometry of Higher Derivative Gravity
We determine the scaling properties of geometric operators such as lengths, areas, and volumes in models of higher derivative quantum gravity by renormalizing appropriate composite operators. We use these results to deduce the fractal dimensions of such hypersurfaces embedded in a quantum spacetime at very small distances
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