CERN Accelerating science

Article
Title	Emittance Growth From Electron Clouds Forming in the LHC Arc Quadrupoles
Author(s)	Paraschou, Konstantinos (CERN) ; Bartosik, Hannes (CERN) ; Deniau, Laurent (CERN) ; Iadarola, Giovanni (CERN) ; Maclean, Ewen (CERN) ; Mether, Lotta (CERN) ; Papaphilippou, Yannis (CERN) ; Pieloni, Tatiana (Ecole Polytechnique, Lausanne) ; Potdevin, Joséphine (Ecole Polytechnique, Lausanne) ; Rumolo, Giovanni (CERN) ; Tomás García, Rogelio (CERN)
Publication	2024
Number of pages	4
In:	JACoW HB 2023 (2024) 487-490
In:	68th ICFA Advanced Beam Dynamics workshop on high-Intensity and High-Brightness Hadron Beams (HB 2023), CERN, Geneva, Switzerland, 9 - 13 Oct 2023, pp.487-490
DOI	10.18429/JACoW-HB2023-THBP16
Subject category	Accelerators and Storage Rings
Abstract	Operation of the Large Hadron Collider with proton bunches spaced 25 ns apart favours the formation of electron clouds. In fact, a slow emittance growth is observed in proton bunches at injection energy (450 GeV), showing a bunch-by-bunch signature that is compatible with electron cloud effects. The study of these effects is particularly relevant in view of the planned HL-LHC upgrade, which relies on significantly increased beam intensity and brightness. Particle tracking simulations that take into account both electron cloud effects and the non-linear magnetic fields of the lattice suggest that the electron clouds forming in the arc quadrupoles are responsible for the observed degradation. In this work, the simulation results are studied to gain insight into the mechanism which drives the slow emittance growth. Finally, it is discussed how optimising the optics of the lattice can allow the mitigation of such effects.
Copyright/License	© 2024 the author(s) (License: CC-BY-3.0)

Corresponding record in: Inspire