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Space-charge effects during half-integer resonance crossing in the CERN Proton Synchrotron Booster

Tirsi Prebibaj*, Fanouria Antoniou, Foteini Asvesta, and Hannes Bartosik

Giuliano Franchetti

  • CERN, Geneva, Switzerland

  • *Contact author: tirsi.prebibaj@cern.ch
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Phys. Rev. Accel. Beams 29, 054201 – Published 12 May, 2026

DOI: https://doi.org/10.1103/rhdk-191j

Abstract

The survival of charged particles in synchrotrons requires avoiding setting the beam on machine resonances, the most dangerous of which are the integer and half-integer. Nevertheless, operationally, the transverse tunes may change dynamically, crossing these resonances and resulting in unwanted beam quality degradation and beam loss. For high-intensity beams, the process of resonance crossing is even more critical, as space charge, in addition to the incoherent effects, may also generate coherent effects. The interplay of the speed of resonance crossing, the space charge incoherent tune spread, and the half-integer resonance width is fundamental for the beam behavior. In this paper, we study the crossing of the half-integer resonance 2Qy=9 in the CERN Proton Synchrotron Booster (PSB) for a range of parameters using a coasting beam. We take advantage of the newly commissioned PSB to investigate the beam response experimentally. The experimental findings are also discussed with the support of simulations.

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Phys. Rev. Accel. Beams 29, 054201– Published 12 May, 2026
  • Received 22 November 2025
  • Accepted 24 March 2026
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