Paper |
Title |
Page |
MOPPC004 |
Experiments on the Margin of Beam Induced Quenches for LHC Superconducting Quadrupole Magnet in the LHC |
124 |
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- C. Bracco, W. Bartmann, M. Bednarek, B. Goddard, E.B. Holzer, A. Nordt, M. Sapinski, R. Schmidt, M. Solfaroli Camillocci, M. Zerlauth, E.N. del Busto
CERN, Geneva, Switzerland
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Protection of LHC equipment relies on a complex system of collimators to capture injected or circulating beam in case of LHC injection kicker magnet failures. However, for specific failures of the injection kicker, the beam can graze the injection protection collimators and induce quenches of downstream superconducting magnets. This occurred twice during 2011 operation and can also not be excluded during further operation. Tests were performed during Machine Development periods of the LHC to assess the quench margin of the quadrupole located just downstream of the last injection protection collimator in point 8. In addition to the existing Quench Protection System, a special monitoring instrumentation was installed at this magnet to detect any resistance increase below the quench limit. The correlation between the magnet and Beam Loss Monitor signals was analysed for different beam intensities and magnet current. The results of the experiments are presented in this paper.
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MOPPD057 |
CERN PSB-to-PS Transfer Modifications for the 2 GeV Upgrade |
493 |
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- W. Bartmann, J. Borburgh, S.S. Gilardoni, B. Goddard, A. Newborough, S. Pittet, R. Steerenberg
CERN, Geneva, Switzerland
- C.H. Yu
IHEP, Beijing, People's Republic of China
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Within the frame of the CERN PS Booster (PSB) energy upgrade from 1.4 to 2 GeV, the PSB to PS transfer line will be adapted for pulse-to-pulse modulated operation. A modified lattice is presented including a re-design of the switching dipole between ISOLDE and PS and additional collimators to protect the PS injection septum. Optics solutions optimized for small emittance LHC beams as well as for the large emittance high-intensity beams are shown.
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MOPPD058 |
LHC Abort Gap Cleaning Studies during Luminosity Operation |
496 |
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- E. Gianfelice-Wendt
Fermilab, Batavia, USA
- W. Bartmann, A. Boccardi, C. Bracco, E. Bravin, B. Goddard, W. Höfle, D. Jacquet, A. Jeff, V. Kain, M. Meddahi, F. Roncarolo, J.A. Uythoven, D. Valuch
CERN, Geneva, Switzerland
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The presence of significant intensities of un-bunched beam is a potentially serious issue in the LHC. Procedures using damper kickers for cleaning both Abort Gap (AG) and buckets targeted for injection, are currently in operation at flat bottom. Recent observations of relatively high population of the AG during physics runs brought up the need for AG cleaning during luminosity operation as well. In this paper the results of experimental studies performed in October 2011 are presented.
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TUPPR093 |
Sources and Solutions for LHC Transfer Line Stability Issues |
2047 |
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- L.N. Drosdal, W. Bartmann, C. Bracco, B. Goddard, V. Kain, G. Le Godec, M. Meddahi, J.A. Uythoven
CERN, Geneva, Switzerland
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The LHC is filled through two 3km transfer lines from the last pre-injector, the SPS. Safe injection into the LHC requires stable trajectories in the transfer lines. During the LHC proton operations 2011 instabilities were observed. In particular shot-by-shot and bunch-by-bunch variations cause difficulties for steering of the beam and can potentially cause high beam losses at injection. The causes of these instabilities have been studied and will be presented in this paper. Based on the studies solutions will be proposed and finally the effects of the solutions will be studied.
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TUPPR094 |
SPS Transverse Beam Scraping and LHC Injection Losses |
2050 |
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- L.N. Drosdal, W. Bartmann, C. Bracco, K. Cornelis, B. Goddard, V. Kain, M. Meddahi, E. Veyrunes
CERN, Geneva, Switzerland
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Machine protection sets strict requirements for the quality of the injected beam, in particular in the transverse plane. Losses at aperture restrictions and protection elements have to be kept at a minimum. Particles in the beam tails are lost at the tight transfer line collimators and can trigger the LHC beam abort system. These particles have to be removed by scrapers in the vertical and horizontal plane in the SPS. Scraping has become vital for high intensity LHC operation. This paper shows the dependence of injection quality on the SPS scraping and discusses an improved scraper setting up strategy for better reproducibility with the current scraper system.
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TUPPR096 |
Angular Alignment of the LHC Injection Protection Stopper |
2056 |
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- C. Bracco, R.W. Assmann, W. Bartmann, B. Goddard, V. Kain, J.A. Uythoven
CERN, Geneva, Switzerland
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Machine safety depends critically on the correct setup of the protection elements. One of the injection protection collimators is constituted by exceptionally long jaws (4 m). For this element, an angular offset of the jaws could affect significantly the measured beam size and, as a consequence, the correct setup with respect to the beam. Dedicated studies and cross-calibrations have been performed to quantify the effect of tilts and offsets on the setup of this collimator and to check the provided passive protection.
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THPPP008 |
The ELENA Project: Progress in the Design |
3740 |
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- T. Eriksson, W. Bartmann, P. Belochitskii, H. Breuker, F. Butin, C. Carli, R. Kersevan, M. Martini, S. Maury, S. Pasinelli, G. Tranquille
CERN, Geneva, Switzerland
- W. Oelert
Forschungszentrum Jülich GmbH, Institut fur Nuklearchemie (INC), Jülich, Germany
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The Extra Low ENergy Antiproton ring (ELENA) project started in June 2011 and is aimed at substantially increasing the number of antiprotons delivered to the Antiproton Decelerator (AD) physics community. ELENA will be a small machine that receives antiprotons from AD at 5.3 MeV kinetic energy and decelerates them further down to 100 keV. It will be equipped with an electron cooler to avoid beam losses during deceleration and to reduce beam phase space at extraction. Design work is progressing with emphasis on machine parameters and design as well as infrastructure, ring, transfer lines and vital subsystem design.
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