| Paper |
Title |
Page |
| TUPP091 |
WISE: a Simulation of the LHC Optics Including Magnet Geometrical Data
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1744 |
| |
- P. Hagen, M. Giovannozzi, J.-P. Koutchouk, T. Risselada, F. Schmidt, E. Todesco, E. Y. Wildner
CERN, Geneva
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The beam dynamics in LHC strongly depends on the field quality and geometry of the magnets. A model of the LHC optics has been built, based on the information available at the end of the production as well as on statistical evaluations for the missing information The pre-processor WISE generates instances of the LHC field errors for the MAD X program, with the possibility of selecting various sources. This paper describes the progress since WISE was presented in EPAC06. The slot allocation in LHC is completed since all magnets are installed and interconnected. Geometric measurements have been added for all magnets. Furthermore, some statistical data is available relative to the precision of magnet installation (alignment) and tunnel movements. In this paper the code and the data are used to update the beta-beating estimate at injection and collision energy. The relevance of misalignments of the different magnets and their impact on beta-beating is compared to the sources that have been previously considered, i.e. the spread in the gradient of the cell quadrupoles and the uncertainty associated to the knowledge of the transfer functions of the stand-alone quadrupoles.
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| WEPD005 |
Scaling Laws for Magnetic Energy in Superconducting Quadrupoles
|
2407 |
| |
- F. Borgnolutti, E. Todesco
CERN, Geneva
- A. Mailfert
ENSEM, Vandoeuvre lès Nancy
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The stored energy in superconducting magnets is one of the main ingredients needed for the quench calculation and for desingin quench protections. Here we proposed an analytical formula based on the Fourier transformation of the current density flowing within the winding to determine the magnetic energy stored in superconducting quadrupoles made of sector coils. Two corrective coefficients allowing to estimate the energy enhancement produced either by current grading or by the presence of an unsaturated iron yoke are respectively derived from a numerical and an analytical study. This approach is applied to a set of real quadrupoles to test the validity limits of the scaling law, which are shown to be of 5-10%.
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| WEPP012 |
Analysis of Optical Layouts for the Phase 1 Upgrade of the CERN Large Hadron Collider Insertion Regions
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2551 |
| |
- M. Giovannozzi, F. Borgnolutti, O. S. Brüning, U. Dorda, S. D. Fartoukh, W. Herr, M. Meddahi, E. Todesco, R. Tomas, F. Zimmermann
CERN, Geneva
- R. de Maria
EPFL, Lausanne
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In the framework of the studies for the upgrade of the insertions of the CERN Large Hadron Collider, four optical layouts were proposed with the aim of reducing the beta-function at the collision point down to 25 cm. The different candidate layouts are presented. Results from the studies performed on mechanical and dynamic aperture are summarized, together with the evaluation of beam-beam effects. Particular emphasis is given to the comparison of the optics performance, which led to retain two promising layouts for further investigation and development.
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| WEPP032 |
Parametric Study of Energy Deposition in the LHC Inner Triplet for the Phase 1 Upgrade
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2590 |
| |
- E. Y. Wildner, F. Borgnolutti, F. Cerutti, M. Mauri, A. Mereghetti, E. Todesco
CERN, Geneva
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To be able to make a global parametric analysis and to have some basic understanding of the influence of critical parameters, scaling laws may be of help. For the design of the LHC collision insertion regions, one of the critical parameters is the energy deposited in the insertion superconducting magnet coils, to avoid magnet quench, too heavy load on the cryogenic system, and degradation of the superconductor due to radiation. The influence on energy deposition of some key parameters for magnet design, such as the magnet apertures, the magnet lengths and positions, has been studied for some specified optical beta-value at the collision point.
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