Beam Transfer Function Measurements and Transverse Stability in presence of Beam-Beam

Authors

  • C. Tambasco EPFL, Lausanne
  • J. Barranco EPFL, Lausanne
  • T. Pieloni EPFL, Lausanne
  • L. Rivkin EPFL, Lausanne
  • X. Buffat CERN, Geneva
  • E. Metral CERN, Geneva

DOI:

https://doi.org/10.23732/CYRCP-2018-001.105

Keywords:

Beam Transfer Function, Transverse stability, Particle accelerator, Collider, Beam- beam interaction, Beam stability, Landau damping, Stability diagram, multi-particle tracking simulation, LHC

Abstract

Instability thresholds are explored at the Large Hadron Collider (LHC) by means of the computation of the Landau Stability Diagram (SD). In the presence of diffusive mechanisms, caused by resonance excitations or noise, the SD can be reduced due to the modification of the particle distribution inside the beam. This effect can lead to a possible lack of Landau damping of the coherent modes previously damped by lying within the unperturbed SD area. The limitations deriving from coherent instabilities in the LHC is crucial in view of future projects that aim to increase the performance of the LHC such as the High-Luminosity upgrade (HL-LHC) or Future Circular Collider (FCC). Simulation tools for the computation of the SD have been extended in order to take into account the incoherent effects from long particle tracking through the detailed model of the accelerator machine. The model include among others beam-beam interactions and octupoles and the interplay between both is addressed. Finally the  simulation results  are compared to the Beam Transfer Function (BTF) measurements in the LHC.

Downloads

Published

2018-11-07

Issue

Vol. 1 (2018): Proceedings of the ICFA Mini-Workshop "Impedances and Beam Instabilities in Particle Accelerators"

Section

Submission to the proc. of the ICFA Mini-Workshop Workshop "Impedances and Beam Instabilities in Particle Accelerators"

License

Authors who publish with this publication agree to the following terms:

  1. CERN retains copyright and publishes the work licensed under the Creative Commons Attribution License 4.0 that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this series.
  2. Authors are able to enter into separate, additional contractual arrangements for distribution of the published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this series.
  3. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).