F. Asvesta, S.C.P. Albright, F. Antoniou, H. Bartosik, C. Bracco, G.P. Di Giovanni, E.H. Maclean, B. Mikulec, T. Prebibaj, E. Renner
CERN, Geneva, Switzerland
Resonance studies have been conducted during the recommissioning of the CERN Proton Synchrotron Booster (PSB) following the implementation of the LHC Injectors Upgrade (LIU) project. In particular, resonance identification through so-called loss maps has been applied on all four rings of the PSB, revealing various resonances up to fourth order. In a second step, compensation schemes for the observed resonances were developed using a combination of analytical methods, experimental data and machine learning tools. These resonance compensation schemes have been deployed in operation to minimize losses for reaching high intensity and high brightness, thereby achieving the target brightness for the LHC-type beams.
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X. Buffat, S.V. Furuseth, G. Vicentini
CERN, Geneva, Switzerland
S.V. Furuseth
EPFL, Lausanne, Switzerland
Control of chromaticity is often critical to mitigate collective instabilities in high energy synchrotrons, yet classical measurement methods are of limited use during high intensity operation. We explore the possibility to extract this information from beam transfer function measurements, with the development of a theoretical background that includes the impact of wakefields and by analysis of multi-particle tracking simulations. The investigations show promising results that could improve the operation of the HL-LHC by increasing stability margins.
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C. Zannini, H. Bartosik, M. Carlà, K.S.B. Li, E. Métral, G. Rumolo, B. Salvant
CERN, Geneva, Switzerland
L.R. Carver
ESRF, Grenoble, France
M. Schenk
EPFL, Lausanne, Switzerland
At the end of 2018, an instability with multiple bunches has been consistently observed during high intensity studies at the CERN-SPS. This instability could be a significant limitation to achieve the bunch intensity expected after the LHC Injector Upgrade (LIU). Therefore, a deep understanding of the phenomena is essential to identify the best mitigation strategy. Extensive simulation studies have been performed to explore the consistency of the current SPS model, give a possible interpretation of the instability mechanism and outline some possible cures.
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J.A.D. Flowerdew
University of Oxford, Oxford, United Kingdom
D.J. Kelliher, S. Machida, S.L. Sheehy
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
An ideal accelerator built from linear components will exhibit bounded and stable particle motion. However, in reality, any imperfections in the magnetic field strength or slight misalignments of components can introduce chaotic and unstable particle motion. All accelerators are prone to these non-linearities but the effects are amplified when studying high intensity particle beams with the presence of space charge effects. This work aims to explore the non-linearities which arise in high intensity particle beams using a scaled experiment called IBEX. The IBEX experiment is a linear Paul trap which allows the transverse dynamics of a collection of trapped particles to be studied. It does this by mimicking the propagation through multiple quadrupole lattice periods whilst remaining stationary in the laboratory frame. IBEX is currently undergoing a nonlinear upgrade with the goal of investigating Quasi-Integrable Optics (QIO), a form of Nonlinear Integrable Optics (NIO), in order to improve our understanding and utilisation of high intensity particle beams.
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