| Paper |
Title |
Page |
| MOPAN023 |
Superconductive Damping Wigglers for the CLIC Project
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200 |
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- R. Rossmanith, S. Casalbuoni, A. W. Grau, M. Hagelstein, B. K. Kostka
FZK, Karlsruhe
- T. Baumbach, A. Bernhard, A.-S. Muller, D. Wollmann
University of Karlsruhe, Karlsruhe
- H.-H. Braun, M. Korostelev, Y. Papaphilippou, F. Zimmermann
CERN, Geneva
- E. M. Mashkina, E. Steffens
University of Erlangen-Nurnberg, Physikalisches Institut II, Erlangen
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The CLIC damping ring requires wigglers with both high on-axis fields and short periods. The present design foresees a superconductive wiggler with a period length of 5 cm, a peak on-axis field of 2.5 T and a full width aperture of 12 mm. In this paper we explore the performance improvements of the damping ring when these parameters are pushed to 2.7 T at a period length of 2 cm with the expense of a reduced aperture of 5 mm. A design for a prototype for testing the field quality of such a wiggler is presented in this paper and the possibility to test this wiggler with beam in the storage ring ANKA is described.
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| MOPAN077 |
Geometry of the LHC Short Straight Sections Before Installation in the Tunnel: Resulting Aperture, Axis and BPM Positioning
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335 |
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- D. P. Missiaen, P. Bestmann, M. C.L. Buzio, S. D. Fartoukh, M. Giovannozzi, J. B. Jeanneret, A. M. Lombardi, Y. Papaphilippou, S. Pauletta, J. C. Perez, H. Prin, E. Y. Wildner
CERN, Geneva
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The Large Hadron Collider Short Straight Sections (SSS) are currently being installed in their final position in the accelerator tunnel. For all the SSSs, both those in the regular arcs as well as those in the insertion regions, magnetic and geometric measurements are made at different steps of their assembly. These stages range from production in the industry to the cryostating at CERN, as well as during and after cold tests or during installation of the BPM and the cold warm transition for the stand alone magnets. The results of the geometry at the various production stages by means of different procedures and analysis tools are reported and discussed in details in this paper.
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| MOPAN085 |
Completion of the Series Fabrication of the Main Superconducting Quadrupole Magnets of LHC
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356 |
| |
- T. Tortschanoff, M. Modena, Y. Papaphilippou, L. Rossi, K. M. Schirm
CERN, Geneva
- R. Burgmer, H.-U. Klein, D. Krischel, B. Schellong, P. Schmidt
ACCEL, Bergisch Gladbach
- M. Durante, A. Payn, J.-M. Rifflet, F. Simon
CEA, Gif-sur-Yvette
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By end of November 2006, the last cold mass of the main superconducting quadrupole cold masses were delivered by ACCEL Instruments to CERN. This comprised 360 cold masses for the arc regions of the machine and 32 special units dedicated to the dispersion suppressor regions. The latter ones contain the same main magnet but different types of correctors and are of increased length with respect to the regular arc ones. The end of the fabrication of these magnets coincided with the end of the main dipole deliveries allowing a parallel assembly into their cryostats and installation into the LHC tunnel. The positioning into the tunnel was optimized using the warm field measurements performed in the factory. On the other hand the correct slotting of the quadrupoles was complicated due to the multitude of variants and by the fact that a number of units needed to be replaced by spares which in some cases required a reshuffling of the positioning. The paper gives some final data about the successful fabrication at ACCEL Instruments and explains the issue of their best positions in the machine.
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| TUODKI02 |
Optics Considerations for the PS2
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739 |
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- M. Benedikt, W. Bartmann, C. Carli, B. Goddard, S. Hancock, J. M. Jowett, Y. Papaphilippou
CERN, Geneva
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CERN envisages replacing the existing Proton Synchrotron (PS) with a larger synchrotron (PS2) capable of injecting at higher energy into the SPS. Since it should increase the performance not only of the LHC but also CNGS and other users of beams from CERN's hadron injector complex, the new accelerator must retain much of the flexibility of the present complex. A number of candidate optics, with and without transition crossing, have been evaluated systematically and compared.
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Slides
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| THPAN065 |
Beam Loss Map Simulations and Measurements in the CERN PS
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3372 |
| |
- J. Barranco, O. E. Berrig, S. S. Gilardoni, J. B. Jeanneret, Y. Papaphilippou
CERN, Geneva
- G. Robert-Demolaize
BNL, Upton, Long Island, New York
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Numerical tools providing detailed beam loss maps, recently developed for the design of the LHC collimation system, were adapted to the CERN Proton Synchrotron in order to reproduce the observed beam loss patterns. Using a MADX optics sequence model, these tools are able to track a large number of particles with Sixtrack and interact with a realistic aperture model to simulate particle losses all around the ring. The modeled loss maps were finally compared with beam loss measurements at several energies and for a variety of beams accelerated in the synchrotron.
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| THPAN074 |
Space-Charge Compensation Options for the LHC Injector Complex
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3390 |
| |
- F. Zimmermann, M. Aiba, M. Chanel, U. Dorda, R. Garoby, J.-P. Koutchouk, M. Martini, E. Metral, Y. Papaphilippou, W. Scandale
CERN, Geneva
- G. Franchetti
GSI, Darmstadt
- V. D. Shiltsev
Fermilab, Batavia, Illinois
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Space-charge effects have been identified as the most serious intensity limitation in the CERN PS and PS booster, on the way towards ultimate LHC performance and beyond. We here explore the application of several previously proposed space-compensation methods to the two LHC pre-injector rings, for each scheme discussing its potential benefit, ease of implementation, beam-dynamics risk, and the R&D programme required. The methods considered include tune shift and resonance compensation via octupoles, nonlinear chromaticity, or electron lenses, and beam neutralization by an electron cloud, plasma or negative ions.
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| FRPMN013 |
Precise Tune Measurements from Multiple Beam Position Monitors
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3913 |
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- Ch. Skokos, J. Laskar
IMCCE, Paris
- Y. Papaphilippou
CERN, Geneva
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Funding: Work supported by the Marie Curie Intra-European Fellowship No MEIF-CT-2006-025678
One of the main limitations for precise tune measurements using kicked turn-by-turn data is the beam decoherence, which can limit the available signal to a reduced number of turns. Applying Laskar's frequency analysis, on measurements from several beam position monitors, a fast and accurate determination of the real tune is possible. The efficiency of the method is demonstrated when applied in turn-by-turn data from the ESRF storage ring and CERN's Super Proton Synchrotron. Estimates from tracking simulations and analytical considerations are further compared with the experimental results.
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| FROAKI01 |
Magnet Acceptance and Allocation at the LHC Magnet Evaluation Board
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3739 |
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- L. Bottura, P. Bestmann, N. Catalan-Lasheras, S. D. Fartoukh, S. S. Gilardoni, M. Giovannozzi, J. B. Jeanneret, M. Karppinen, A. M. Lombardi, K. H. Mess, D. P. Missiaen, M. Modena, R. Ostojic, Y. Papaphilippou, P. Pugnat, S. Ramberger, S. Sanfilippo, W. Scandale, F. Schmidt, N. Siegel, A. P. Siemko, D. Tommasini, T. Tortschanoff, E. Y. Wildner
CERN, Geneva
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The normal- and superconducting magnets for the LHC ring have been carefully examined to insure that each of the more than 1800 assemblies is suitable for the operation in the accelerator. Magnet coordinators, hardware experts and accelerator physicists, joined in the LHC Magnet Evaluation Board, have contributed to this work that consists in the magnet acceptance, and the optimisation achieved by sorting magnets according to their geometry, field quality and quench level. This paper gives a description of the magnet approval mechanism that has been running since four years, reporting in a concise summary on the main results achieved. We take as specific indicators the computed mechanical aperture, the sorting efficiency with respect to systematic and random field errors in the magnets, and the case-by-case analysis necessary to accommodate hardware limitations such as quench limits and training.
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Slides
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