CERN, Geneva
The start-up of the LHC has provided the first field test for the concept, functionality and accuracy of FiDeL, the Field Description for the LHC. FiDeL is primarily a parametric model of the transfer function of the main field integrals generated by the series of magnets in the LHC powering circuits, from main optical elements to high-order harmonic correctors, both superconducting and normal-conducting magnets. In addition, the same framework is used to predict harmonic errors of both static and dynamic nature, and forecast appropriate corrections. In this paper we give a description of the level of detail achieved in the model and the rationale adopted for the LHC start-up. Beam-based measurements have been used for an assessment of the first-shot accuracy in the prediction of the current setting for the main arc magnets*.
*The work reported has been performed by the authors and the FiDeL Team
CERN, Geneva
An LHC high-luminosity upgrade has been studied by various European and international collaborations since about 2001. Ingredients of such an LHC upgrade include the optimization of the IR layout, new high-field or large-aperture triplet quadrupoles, chromatic correction, possibly detector-integrated slim magnets, crab cavities, beam-beam compensators, operation in a regime of large Piwinski angle, luminosity leveling for reduced detector pile up, heat-load, background, and radiation damage due to the collision debris, and a renovation of the injector complex. Scenarios, decision paths, and present R&D efforts will be presented.
