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arXiv · 2610.29951

Evaluation of Transverse Incoherent Tune Shifts in the Electron-Ion Collider

Xiaofeng Gu·Alexei Blednykh
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Abstract

Achieving the Electron-Ion Collider (EIC) peak luminosity goal of 10 to the power of 34 per square centimeter per second requires high average currents, flat beams, non-circular vacuum chambers, and large transverse orbit offsets in the Hadron Storage Ring (HSR) and Electron Storage Ring (ESR). These conditions can generate collective effects and incoherent tune spreads that drive particles across low-order betatron resonances, causing emittance growth, halo formation, and reduced beam lifetime. We quantitatively evaluate incoherent transverse betatron tune shifts from beam-beam interactions, direct space charge, and beam-environment interactions associated with image forces and vacuum chamber geometry. Xsuite and PyHEADTAIL simulations validate the analytical calculations for beam-beam and direct space-charge effects, respectively. For indirect space-charge effects, we review and compare several analytical formalisms and apply the Laslett image-charge formulation to rectangular vacuum chambers with off-axis beams. The analysis accounts for transverse orbit offsets of up to 20 mm in the HSR and 10 mm in the ESR. The results establish baseline parameters and provide quantitative guidance for EIC design, optimization, and operation. The comparison of indirect space-charge formalisms also offers an accessible reference and methodology for studies of high-intensity beam dynamics.

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Xiaofeng Gu, Alexei Blednykh. 2026-10-21. Evaluation of Transverse Incoherent Tune Shifts in the Electron-Ion Collider. https://arxiv.org/abs/2610.29951

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