TUA2C1
EPFL, Lausanne, Switzerland
CERN, Meyrin, Switzerland
CEA, Gif-sur-Yvette, France
PU, Princeton, New Jersey, USA
La Sapienza University of Rome, Rome, Italy
CERN, Meyrin, Switzerland
INFN-Roma1, Rome, Italy
| Paper | Title | Page |
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TUA2C1 |
Beam-Beam Effects: Modelling, Measurements and Correction Strategy on the Luminosity Calibration Measurements at the Large Hadron Collider Experiments | |
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| At the Large Hadron Collider (LHC), absolute luminosity calibrations obtained by the van der Meer (vdM) method and operational luminosity variations during physics fills are biased by the mutual electromagnetic interaction of the two beams, the beam-beam effects. The colliding bunches experience relative orbit shifts, optical distortions as well as transverse distribution deviations from Gaussians that must be accounted and corrected for when deriving the absolute luminosity scale and when monitoring detector performances during physics runs. In this study the impact of beam-beam effects on the absolute luminosity measurements will be shown by means of numerical simulations, together with the associated systematic uncertainties to the visible cross sections. The biases to the absolute calibrations are also described together with the correction scheme developed and used as part of the detector data analysis. Simulation studies will be compared to data collected during a dedicated experimental study with the CMS, ATLAS and ALICE detectors. Models and experimental data are compared at 1% level, showing an impressive agreement between numerical expectations and experimental data. | ||
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Slides TUA2C1 [3.967 MB] | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
| TUA2C2 | Recent Advances in the CERN PS Impedance Model and Instability Simulations | 86 |
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| Transverse instability growth rates in the CERN Proton Synchrotron are studied thanks to the recently updated impedance model of the machine. Using this model, macroparticle tracking simulations were performed with a new method well-suited for the slicing of short wakes, which achieves comparable performance to the originally implemented method while reducing the required number of slices by a factor of 5 to 10. Dedicated beam-based measurement campaigns were carried out to benchmark the impedance model. Until now, the model underestimated instability growth rates at injection energy. Thanks to a recent addition to the impedance model, namely the kicker magnets¿ connecting cables and their external circuits, the simulated instability growth rates are now comparable to the measured ones. | ||
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Slides TUA2C2 [0.736 MB] | |
| DOI • | reference for this paper ※ doi:10.18429/JACoW-HB2023-TUA2C2 | |
| About • | Received ※ 28 September 2023 — Revised ※ 07 October 2023 — Accepted ※ 09 October 2023 — Issued ※ 21 October 2023 | |
| Cite • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |