1,280 research outputs found
The PS in the LHC injector chain
This is an overview of the PS for LHC beam requirements in terms of beam characteristics and an inventory of various issues and problems to be solved to reach the desired performance
CERN PS high brightness operation for LHC
The paper is a short description, for non specialists, of some of the main machine physics issues concerning the production and the conservation of high brightness beams in the pre-injector chain of the LHC machine
The Fundamental Plane of Galaxy Clusters
Velocity dispersion , radius and luminosity of elliptical
galaxies are known to be related, leaving only two degrees of freedom and
defining the so-called ``fundamental plane". In this {\em Letter} we present
observational evidence that rich galaxy clusters exhibit a similar behaviour.
Assuming a relation , the best-fit values
of and are very close to those defined by galaxies. The
dispersion of this relation is lower than 10 percent, i.e. significantly
smaller than the dispersion observed in the and relations. We
briefly suggest some possible implications on the spread of formation times of
objects and on peculiar velocities of galaxy clusters.Comment: 11pp., 4 figures (available on request), LaTeX, BAP-04-1993-015-OA
Novel Method for Multi-turn Extraction: trapping charged Particles in Islands of Phase Space
A novel method for multi-turn extraction from a circular particle accelerator is presented. It is based on trapping particles into islands of phase space generated by nonlinear resonances. By appropriate use of nonlinear elements (sextupoles, octupoles), stable islands can be created at small amplitude in phase space. By varying the linear tune, it is shown how particles can be trapped inside these islands. The particles can then be coherently transported towards higher amplitudes for extraction. Results of numerical simulations are presented and discussed in detail
Computation of betatron mismatch and emmitance blow-up for multi-turn extraction
The present version of the five-turn Continuous Transfer extraction at PS machine is based on beam slicing by means of an electrostatic septum. Recently, a novel approach has been proposed, where the beam is split into five beamlets by means of stable islands, created by sextupoles and octupoles, together with a proper tune variation. In this paper, the two approaches are compared by considering their properties in terms of equivalent optical parameters, beam emittance, and emittance after filamentation in the receiving machine (SPS) for the various slices. Analytic expressions of the relevant optical and beam parameters are derived for the present version of the Continuous Transfer, while the same quantities are estimated in the case of the novel approach via numerical simulations. Finally, the robustness of the approach based on adiabatic capture in transverse phase space is discussed with particular emphasis on tune ripple effects and variation of nonlinear elements strength
Multiturn Extraction: Performance Analysis of Old and New Approaches
Super Proton Synchrotron. The present approach is based on beam slicing via an electrostatic septum. However, recently a novel technique was proposed. By using nonlinear magnetic elements, stable islands can be generated in the transverse phase space. Furthermore, if the linear tune is varied slowly, it is possible to trap the charged particles inside the stable islands so that the beam is split into different beamlets ready for extraction. In this paper, both techniques are discussed in details with special emphasis on their robustness and the phase space matching of the extracted beam
Collective Effects in the CERN-PS beam for LHC
This paper is an updated review of the collective effects observed and predicted in the CERN-PS machine for the LHC beam
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