| Paper |
Title |
Page |
| MOPLT006 |
The New Layout of the LHC Cleaning Insertions
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539 |
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- R.W. Assmann, O. Aberle, O.S. Brüning, S. Chemli, D. Gasser, J.-B. Jeanneret, J.M. Jimenez, V. Kain, E. Métral, G. Peon, S. Ramberger, C. Rathjen, T. Risselada, F. Ruggiero, L. Vos
CERN, Geneva
- D. Kaltchev
TRIUMF, Vancouver
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The improved LHC collimation system required significant changes in the layout and design of the warm insertion IR7. Requirements for collimation, optics, impedance, vacuum, and additional infrastructure are described and the adopted layout is discussed. Various design principles have been explored during the re-design, ranging from a regular 90 degree lattice and special low impedance lattices to an option with additional warm quadrupole units that could have extended the usable space for collimator installations in the insertion. The various constraints for the optics and cleaning design in the LHC cleaning insertions are summarized. Magnet positions and collimators were moved significantly, such that a good cleaning efficiency was maintained while impedance was reduced by a factor of two. Metallic phase 2 collimators allow a better efficiency than originally achievable and additional scrapers were allocated. The required infrastructure was specified, including a powerful cooling system for the collimators.
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| MOPLT005 |
An Improved Collimation System for the LHC
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536 |
| |
- R.W. Assmann, O. Aberle, A. Bertarelli, H.-H. Braun, M. Brugger, L. Bruno, O.S. Brüning, S. Calatroni, E. Chiaveri, B. Dehning, A. Ferrari, B. Goddard, E.B. Holzer, J.-B. Jeanneret, J.M. Jimenez, V. Kain, M. Lamont, M. Mayer, E. Métral, R. Perret, S. Redaelli, T. Risselada, G. Robert-Demolaize, S. Roesler, F. Ruggiero, R. Schmidt, D. Schulte, P. Sievers, V. Vlachoudis, L. Vos, G. Vossenberg, J. Wenninger
CERN, Geneva
- I.L. Ajguirei, I. Baishev, I.L. Kurochkin
IHEP Protvino, Protvino, Moscow Region
- D. Kaltchev
TRIUMF, Vancouver
- H. Tsutsui
SHI, Tokyo
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The LHC design parameters extend the maximum stored beam energy 2-3 orders of magnitude beyond present experience. The handling of the high-intensity LHC beams in a super-conducting environment requires a high-robustness collimation system with unprecedented cleaning efficiency. For gap closures down to 2mm no beam instabilities may be induced from the collimator impedance. A difficult trade-off between collimator robustness, cleaning efficiency and collimator impedance is encountered. The conflicting LHC requirements are resolved with a phased approach, relying on low Z collimators for maximum robustness and hybrid metallic collimators for maximum performance. Efficiency is further enhanced with an additional cleaning close to the insertion triplets. The machine layouts have been adapted to the new requirements. The LHC collimation hardware is presently under design and has entered into the prototyping and early testing phase. Plans for collimator tests with beam are presented.
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| WEPLT005 |
Building Truncated Taylor Maps with Mathematica and Applications to FFAG
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1822 |
| |
- D. Kaltchev
TRIUMF, Vancouver
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Lie algebra tools coded directly in Mathematica have been used to compute the off-momentum closed orbit, orbit length and horizontal tune of Fixed Field Alternating Gradient (FFAG) lattices proposed for muon acceleration. The sample FFAG cell considered consists of quadrupoles and alternating gradient magnets. A high order Taylor map is needed, valid over a wide momentum range. We describe the algorithm and Mathematica operators needed to create and concatenate individual element maps (presented as Lie exponential operators) and compare our results with those obtained with a high-order differential algebra code – COSY. The speed achieved is inferior to the differential algebra method.
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