| Paper |
Title |
Page |
| MPPE011 |
Expected Emittance Growth and Beam Tail Repopulation from Errors at Injection into the LHC
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1266 |
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- B. Goddard, H. Burkhardt, V. Kain, T. Risselada
CERN, Geneva
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The preservation of the transverse emittance of the proton beam at injection into the LHC is crucial for luminosity performance. The population of the beam tails is also important for beam losses and collimation. The transfer and injection process is particularly critical in this respect, and several effects can contribute to the expected emittance increase and tail repopulation, like optical and geometrical mismatch, injection offsets and coupling, etc. The various effects are described, together with the tolerance limits on the parameters, and the expected contributions evaluated analytically where possible. The emittance growth and tail distributions are also simulated numerically using realistic errors. The implications for the tolerances on the matching of the transfer lines are discussed.
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| MPPE047 |
Optics Flexibility and Matching at LHC Injection
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2983 |
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- H. Burkhardt, O.S. Brüning, B. Goddard, V. Kain, V. Mertens, T. Risselada, A. Verdier
CERN, Geneva
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An excellent match between the SPS, the several kilometers long transfer lines and the LHC will be required to minimise emittance blow-up at injection. Several optics changes in the SPS and the LHC injection insertions had to be accommodated in the design phase. The new 3-phase collimation system in the transfer lines results in additional phase advance constraints. It will be important to maintain some tuning range for the LHC commissioning phase and to accommodate possible further optics changes. We analyse the requirements, the constraints, the current status and options to enhance the optics flexibility.
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| TPAP009 |
Collimation in the Transfer Lines to the LHC
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1135 |
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- H. Burkhardt, B. Goddard, Y. Kadi, V. Kain, T. Risselada, W.J.M. Weterings
CERN, Geneva
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Injection intensities for the LHC are over an order of magnitude above damage level. The TI 2 and TI 8 transfer lines between the SPS and LHC are each about 2.5 km long and comprise many active elements running in pulsed mode. The collimation system in the transfer lines is designed to dilute the beam energy sufficiently in case of accidental beam loss or mis-steered beam. A system using three collimator families spaced by 60 degrees in phase advance, both in the horizontal and the vertical plane has been chosen. We discuss the reasons for this choice, the layout and, the expected performance of the system in terms of maximum amplitudes and energy deposition.
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