- Open Access
Evaluation of wakefield effects caused by the orbit fluctuation on nanometer scale beams at the Accelerator Test Facility
Phys. Rev. Accel. Beams 29, 083502 – Published 7 August, 2026
DOI: https://doi.org/10.1103/zms6-ngsh
Abstract
Future electron-positron linear colliders require extremely small beam sizes at the interaction point (IP) to achieve high luminosity. The Accelerator Test Facility (ATF) at KEK has been developed to demonstrate the required beam focusing scheme, achieving a vertical size of 37 nm at the virtual IP using a low-emittance beam generated in a damping ring. However, as nanometer scale focusing requires specialized optics, even small kicks in the beamline can lead to significant distortions at the IP. Transverse wakefield effects have previously been observed as beam size growth with increasing bunch intensity and have been primarily interpreted as static effects arising from orbit distortion and misalignment. Dynamic wakefield effects caused by pulse-by-pulse beam orbit fluctuations have also been suggested by previous measurements and investigated through numerical simulations; however, a direct experimental and quantitative evaluation has not been reported. In this paper, we present the first experimental and quantitative study of dynamic wakefield effects on nanometer scale beams at the ATF. Controlled orbit fluctuations were introduced using steering magnets, enabling systematic measurements over a wide range of fluctuation amplitudes without changing the beam optics configuration. The resulting beam size growth was quantitatively evaluated through both experiments and simulations incorporating all wakefield sources in the beamline. The results demonstrate that dynamic wakefield effects can significantly contribute to beam size growth and must therefore be taken into account to achieve stable nanometer scale beams in future linear colliders.
Physics Subject Headings (PhySH)
Article Text
References (15)
- C. Adolphsen, M. Barone, B. Barish et al., The international linear collider: Technical design report(TDR), Technical Report, 2013.
- F. Hinonde et al., ATF accelerator test facility: Design and study report, Technical Report, 1995.
- ATF2 Collaboration, ATF2 proposal, Technical Report, 2005.
- K. Kubo et al., Extremely low vertical-emittance beam in the accelerator test facility at KEK, Phys. Rev. Lett. 88, 194801 (2002).
- Y. Honda et al., Achievement of ultralow emittance beam in the accelerator test facility damping ring, Phys. Rev. Lett. 92, 054802 (2004).
- G. R. White et al., Experimental validation of a novel compact focusing scheme for future energy-frontier linear lepton colliders, Phys. Rev. Lett. 112, 034802 (2014).
- J. Snuverink et al., Measurements and simulations of wakefields at the accelerator test facility 2, Phys. Rev. Accel. Beams 19, 091002 (2016).
- D. Bett et al., A sub-micron resolution, bunch-by-bunch beam trajectory feedback system and its application to reducing wakefield effects in single-pass beamlines, in Proc. Twelfth IPAC, Campinas, SP, Brazil (JACoW Publishing, Geneva, Switzerland, 2021), pp. 1382–1385, 10.18429/JACoW-IPAC2021-TUPAB020.
- P. Korysko, P. N. Burrows, A. Latina, and A. Faus-Golfe, Wakefield effects and mitigation techniques for nanobeam production at the KEK accelerator test facility 2, Phys. Rev. Accel. Beams 23, 121004 (2020).
- P. B. Wilson, Introduction to wakefields and wake potentials, in AIP Conf. Proc. (American Institute of Physics (AIP), New York, 1989), Vol. 184, pp. 525–564.
- K. Kubo, ILC new luminosity design and small beam experiments at ATF, in ALCW2018 (2018).
- http://www.gdfidl.de/.
- http://acc-physics.kek.jp/SAD/.
- T. Shintake, Proposal of a nanometer beam size monitor for linear colliders, Nucl. Instrum. Methods Phys. Res. A 311, 453 (1992).
- T. Suehara et al., A nanometer beam size monitor for ATF2, Nucl. Instrum. Methods A 616, 1 (2010).
