HB2025 - the 71st ICFA Advanced Beam Dynamics workshop on High-Intensity and High-Brightness Hadron Beams

Optimization of beam performance by correction of impedance driven tune shifts at the CERN SPS

WECDB03

Oct 22, 2025, 5:40 PM

20m

Contributed Oral Presentation WGA:Beam Dynamics in Rings WECDB WGA contributed oral

Speaker

Ingrid Mases (European Organization for Nuclear Research)

Description

High-intensity multi-bunch beams in the CERN Super Proton Synchrotron (SPS) experience significant coherent and incoherent tune shifts due to the transverse beam coupling impedance. Studies with LHC-type beams have been performed to optimize the working point along the extended SPS injection plateau to enhance beam performance and brightness. The initial tune correction approach focused on adjusting the coherent tunes at each injection. However, measurements showed that maintaining the incoherent tunes of the beam constant with multiple beam injections allows improving beam brightness by avoiding emittance growth due to resonances in the presence of space charge. We report here about measurements of emittance growth and beam losses for various working points and tune correction approaches in the multi-bunch scenarios. The results indicate that maintaining the incoherent tunes constant effectively mitigates emittance growth, leading to enhanced beam brightness. These findings highlight the critical role of incoherent tunes in optimizing high-brightness beams in the SPS.