| Paper |
Title |
Page |
| MOPA005 |
Protection Against Accidental Beam Losses at the LHC
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492 |
| |
- J. Wenninger, R. Schmidt
CERN, Geneva
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Protection of the LHC against uncontrolled beam losses is of prime importance due to the very high stored beam energy. For nominal beam intensities, each of the two 7 TeV/c proton beams has a stored energy of 350 MJ threatening to damage accelerator equipment. At injection a number of passive beam absorbers must be correctly positioned and specific procedures have been proposed to ensure safe injection of high intensity. The LHC beam dump block being the only LHC element that can safety absorb the full LHC beam, it is essential that the beams are extracted unto the dump block in case of emergency. The failure time constants extend from 100 microseconds to few seconds depending on the equipment. Failures must be detected at a sufficiently early stage and transmitted to the beam interlock system that triggers the beam dumping system. To ensure safe operation the machine protection system uses a variety of systems to detect such failures. The strategy for protection of the LHC will be illustrated, with emphasis on new developments and studies that aim for an increased redundancy of the protection system.
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| TPAP011 |
Reliability Assessment of the LHC Machine Protection System
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1257 |
| |
- R. Filippini, B. Dehning, G. Guaglio, F. Rodriguez-Mateos, R. Schmidt, B. Todd, J.A. Uythoven, A. Vergara-Fernández, M. Zerlauth
CERN, Geneva
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A large number of complex systems will be involved in ensuring a safe LHC operation, such as beam dumping and collimation, beam loss and position detection, quench protection, power interlock controller and beam interlock system. The latter will monitor the status of all other systems and trigger the beam abort if necessary. While the overall system is expected to provide an extremely high level of protection, none of the involved components should unduly impede machine operation by creating physically unfounded dump requests or beam inhibit signals. This paper investigates the resulting trade-off between safety and availability and provides quantitative results for the most critical protection elements.
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| RPPE016 |
Protection Level During Extraction, Transfer and Injection into the LHC
|
1505 |
| |
- V. Kain, B. Goddard, R. Schmidt, J. Wenninger
CERN, Geneva
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Failures during the LHC transfer and injection process cannot be excluded and beam loss with the foreseen intensities and energies, which are an order of magnitude above the damage limit, could cause serious equipment damage. Consequences of equipment failures such as kicker erratics, power converter faults, etc. are investigated by means of a Monte Carlo based on MAD-X tracking with a full aperture model of the transfer line and the injection region. Geometrical and optical mismatch, orbit tolerances, mechanical tolerances for settings of protection elements, power converter ripples, misalignment of elements, etc. are all taken into account. The required performance of the protection system is discussed. The overall protection level for the LHC and the transfer lines during injection is presented.
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| RPPE018 |
Material Damage Test with 450 GeV LHC-Type Beam
|
1607 |
| |
- V. Kain, J. Ramillon, R. Schmidt, K.V. Vorderwinkler, J. Wenninger
CERN, Geneva
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The design of LHC protection elements is based on assumptions on damage levels, which are derived from simulations. A dedicated experiment was prepared and carried out to cross-check the validity of this approach by trying to damage material in a controlled way with beam. The impact of a 450 GeV beam extracted from the SPS on a specially designed high-Z target with a simple geometry, comprising several typical materials used for LHC equipment, was simulated. The beam intensities for the test were chosen to exceed the damage limits of parts of the target. Results of the simulations are presented and compared with test results.
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