| Paper |
Title |
Other Keywords |
Page |
| MOCP03 |
Status of the LHC
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proton, luminosity, injection, superconducting-magnet |
44 |
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- R. Schmidt
CERN, Geneva
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For the LHC to provide particle physics with proton-proton collisions at a centre of mass energy of 14 TeV with a luminosity of 1034 cm-2s-1, the machine will operate with high-field dipole magnets using NbTi superconductors cooled to below the λ point of helium. The construction follows a decade of intensive R&D and technical validation of major collider sub-systems. Installation of the accelerator system is in full swing. Commissioning of the injector complex is well advanced, including beam transfer through one of the transfer lines from SPS to LHC. In the LHC machine, commissioning of the cryogenic system and powering system has started. The status of the LHC accelerator and a brief outlook to operation and its consequences for the machine protection systems will be given. The strategy for the machine protection and beam cleaning will have a major impact on commissioning and operation since each of the two LHC proton beam has a stored energy of about 360 MJ. A fraction of less than 10-3 of the full beam threatens to damage accelerator equipment in case of uncontrolled beam loss, and only 10-8 protons could already quench a magnet.
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| TUAX05 |
Studies of e-cloud build up for the FNAL main injector and for the LHC
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electron, dipole, simulation, injection |
102 |
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- M. A. Furman
LBNL, Berkeley, California
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We present a summary of recent simulation studies of the electron-cloud (EC) build-up for the FNAL Main Injector and for the LHC. In the first case we pay particular attention to the dependence on bunch intensity (Nb) at injection energy, and we focus on the dipole magnets and field-free regions. The saturated value of the average EC density shows a clear threshold in Nb beyond which the beam will be approximately neutralized on average. For the case of the LHC we limit our discussion to arc dipoles at collision energy, and bunch spacings tb=25 ns or tb=75 ns. The main variables exercised in this study are Nb and the peak value of the secondary emission yield (dmax). For tb=25 ns we conclude that the EC power deposition is comfortably below the available cooling capacity of the cryogenic system if dmax is below ~1.2 at nominal Nb. For tb=75 ns, the EC power deposition is insignificant. As a byproduct of this exercise, we reach a detailed understanding of the significant role played by the backscattered secondary electrons.
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