CERN Accelerating science

Internal Note
Report number	CERN-ACC-Note-2021-0003
Title	Space charge and intrabeam scattering effects for Lead-ions and Oxygen-ions in the LHC injector chain
Author(s)	John, Isabelle (Lund University (SE)) ; Bartosik, Hannes (CERN)
Corporate author(s)	CERN. Geneva. ATS Department
Publication	2021
Imprint	11 Jan 2021
Number of pages	31
Subject category	Accelerators and Storage Rings
Accelerator/Facility, Experiment	CERN LEIR CERN PS CERN SPS CERN LHC
Keywords	Pb ions ; 0 ions ; LHC injector chain ; SPS ; Space Charge ; Intrabeam scattering ; Beam losses ; Simulation
Abstract	In the context of a possible LHC run with Oxygen-ion beams in about 2023, this report presents results of the space charge and intrabeam scattering effects for the Oxygen beam in comparison to the operational Lead beam in the LHC ion-injector chain (LEIR, PS and SPS). Analytical calculations of the space charge tune shift indicate no limitations for an Oxygen beam in LEIR and PS as the tune shifts are smaller for Oxygen than for Lead. However, the tune shift for Oxygen is large in the SPS and thus macroparticle simulations (frozen and self-consistent) are performed to study the space charge effects on the Oxygen beam. These simulations predict a fast emittance blow-up of the Oxygen beam by about a factor of two, which might result in particle loss on the machine aperture. It is suggested to consider bunch splitting in the PS to reduce the intensity per bunch in the SPS. No limitations from intrabeam scattering are expected for the Oxygen beam, since the emittance growth calculated with numerical and analytical intrabeam scattering methods is much smaller for the Oxygen beam than for the Lead beam in all three injectors.
Submitted by	[email protected]