Paper |
Title |
Page |
TUPPR098 |
Comparison of LHC Collimator Beam-Based Alignment Centers to BPM-Interpolated Centers |
2062 |
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- G. Valentino, N.J. Sammut
University of Malta, Information and Communication Technology, Msida, Malta
- R.W. Assmann, R. Bruce, G.J. Müller, S. Redaelli, A. Rossi, G. Valentino
CERN, Geneva, Switzerland
- L. Lari
IFIC, Valencia, Spain
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The beam centers at the Large Hadron Collider collimators are determined by beam-based alignment, where both jaws of a collimator are moved in separately until a loss spike is detected on a Beam Loss Monitor downstream. Orbit drifts of more than a few hundred micrometers cannot be tolerated, as they would reduce the efficiency of the collimation system. Beam Position Monitors (BPMs) are installed at various locations around the LHC ring, and a linear interpolation of the orbit can be obtained at the collimator positions. In this paper, the results obtained from beam-based alignment are compared with the orbit interpolated from the BPM data throughout the 2011 LHC proton run. The stability of the orbit determined by collimator alignment during the run is evaluated.
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TUPPR097 |
Modeling and Simulation of LHC Beam-Based Collimator Setup |
2059 |
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- G. Valentino, N.J. Sammut
University of Malta, Information and Communication Technology, Msida, Malta
- R.W. Assmann, F. Burkart, S. Redaelli, A. Rossi, D. Wollmann
CERN, Geneva, Switzerland
- L. Lari
IFIC, Valencia, Spain
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In the 2011 Large Hadron Collider run, collimators were aligned for proton and heavy ion beams using a semi-automatic setup algorithm. The algorithm provided a reduction in the beam time required for setup, an elimination of beam dumps during setup and higher accuracy with respect to manual alignment. A collimator setup simulator was developed based on a Gaussian model of the beam distribution as well as a parametric model of the beam losses. A time-varying beam loss signal can be simulated for a given collimator movement into the beam. The simulation results and comparison to measurement data obtained during collimator setups and dedicated fills for beam halo scraping are presented. The simulator will then be used to develop a fully automatic collimator alignment algorithm.
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