- Physical Review Journals
All JournalsPhysics Magazine

Physical Review Accelerators and Beams

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Open Access

Seeding of self-modulation using truncated seed bunches as a path to high gradient acceleration

N. Z. van Gils1,2, E. Belli2,3, M. Bergamaschi2,4, A. Clairembaud4, A. Gerbershagen1,3, E. Gschwendtner2, H. Jaworska5, J. Mezger4, M. Moreira2 et al. (AWAKE Collaboration)

M. Moreira2, P. Muggli2,4, F. Pannell6, L. Ranc4, M. Turner2, C. C. Ahdida2, Y. Alekajbaf7, C. Amoedo2, O. Apsimon8,9, R. Apsimon9,10, T. Bachmann2, C. Badiali11, M. Baquero12, A. Boccardi2, T. Bogey2, S. Burger2, P. N. Burrows3, B. Buttenschön13, A. Caldwell4, M. Chung14, C. C. Cobo15, D. A. Cooke6, D. Dancila7, C. Davut8,9, G. Demeter16, A. C. Dexter9,10, S. Doebert2, A. Eager2, D. Easton17, B. Elward18, J. Farmer4, R. Fonseca19,11, I. Furno12, D. Ghosal9,20, E. Granados2, J. Gregory9,10, O. Grulke13,21, E. Guran2, D. Harryman2, M. Hibberd8,9, P. Karataev22, R. Karimov12, M. A. Kedves16, F. Kraus23, M. Krupa2, T. Lefevre2, N. Lopes11, K. Lotov, J. Mcgunigal8,9, B. Moser2, Z. Najmudin15, S. Norman8,9, N. Okhotnikov, A. Omoumi2, C. Pakuza2, A. Pardons2, J. Pisani17, A. Pukhov5, R. Rossel2, H. Saberi8,9, M. V. dos Santos2, O. Schmitz18, F. Sharmin18, F. Silva24, L. Silva11, B. Spear3, L. Stant2, C. Stollberg12, A. Sublet2, C. Swain9,20, G. Tenasini2, A. Topaloudis2, P. Tuev, J. Uncles17, F. Velotti2, J. Vieira11, C. Welsch9,20, T. Wilson5, M. Wing6, J. Wolfenden9,20, B. Woolley2, G. Xia9,8, V. Yarygova, and W. Zhang3 (AWAKE Collaboration)

  • 1PARTREC, UMCG, University of Groningen, Groningen, Netherlands
  • 2CERN, 1211 Geneva 23, Switzerland
  • 3John Adams Institute for Accelerator Science, University of Oxford, Oxford, United Kingdom
  • 4Max Planck Institute for Physics, Munich, Germany
  • 5Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
  • 6University College London, London, United Kingdom
  • 7Uppsala University, Uppsala, Sweden
  • 8University of Manchester, Manchester M13 9PL, United Kingdom
  • 9Cockcroft Institute, Warrington WA4 4AD, United Kingdom
  • 10Lancaster University, Lancaster LA1 4YB, United Kingdom
  • 11GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
  • 12Ecole Polytechnique Federale de Lausanne (EPFL), Swiss Plasma Center (SPC), 1015 Lausanne, Switzerland
  • 13Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
  • 14POSTECH, Pohang 37673, Republic of Korea
  • 15Imperial College London, London SW7 2AZ, United Kingdom
  • 16HUN-REN Wigner Research Centre for Physics, Budapest, Hungary
  • 17GWA, Cambridge, CB4 0WS UK
  • 18University of Wisconsin, Madison, Wisconsin 53706, USA
  • 19DCTI/ISCTE, Instituto Universitario de Lisboa, 1649-026, Lisboa, Portugal
  • 20University of Liverpool, Liverpool L69 7ZE, United Kingdom
  • 21Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
  • 22Royal Holloway University of London, Egham, Surrey, TW20 0EX, United Kingdom
  • 23Universität Bonn, 53121 Bonn, Germany
  • 24INESC-ID, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal

PDF

Phys. Rev. Accel. Beams 29, 083601 – Published 31 August, 2026

DOI: https://doi.org/10.1103/c7jm-hf4q

Abstract

This manuscript proposes a method to enable controlled high gradient particle acceleration when requiring self-modulation (SM) of the drive bunch. While electron bunch seeding of self-modulation has been realized at a plasma electron density [L. Verra et al., (AWAKE Collaboration), Controlled growth of the self-modulation of a relativistic proton bunch in plasma, Phys. Rev. Lett. 129, 024802 (2022)], it has not been demonstrated at higher plasma densities due to limitations of available seed bunch properties. As experimentally shown in this manuscript, truncating available seed bunches with a relativistic ionization front allows these limitations to be overcome. This seeding method is called truncated electron bunch seeding of self-modulation (teSSM), and experiments confirm that—when using teSSM—self-modulation becomes reproducible. Additionally, the seed wakefield amplitude is also increased, which is known to be advantageous because it shortens the length needed to reach self-modulation saturation. The presented results establish teSSM as a method for achieving controlled, high gradient particle acceleration with long drivers and available seed bunches.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (34)

  1. E. Esarey, C. B. Schroeder, and W. P. Leemans, Physics of laser-driven plasma-based electron accelerators, Rev. Mod. Phys. 81, 1229 (2009).
  2. T. Tajima and J. M. Dawson, Laser electron accelerator, Phys. Rev. Lett. 43, 267 (1979).
  3. A. Caldwell, K. Lotov, A. Pukhov, and F. Simon, Plasma wakefield acceleration with a proton beam, Nat. Phys. 5, 363 (2009).
  4. AWAKE Collaboration, Acceleration of electrons in the plasma wakefield of a proton bunch, Nature (London) 561, 363 (2018).
  5. E. Gschwendtner et al. (AWAKE Collaboration), The awake run 2 programme and beyond, Symmetry 14, 1680 (2022).
  6. M. Turner et al. (AWAKE Collaboration), Experimental study of wakefields driven by a self-modulating proton bunch in plasma, Phys. Rev. Accel. Beams 23, 081302 (2020).
  7. N. Kumar, A. Pukhov, and K. Lotov, Self-modulation instability of a long proton bunch in plasmas, Phys. Rev. Lett. 104, 255003 (2010).
  8. M. Turner et al. (AWAKE Collaboration), Experimental observation of plasma wakefield growth driven by the seeded self-modulation of a proton bunch, Phys. Rev. Lett. 122, 054801 (2019).
  9. C. B. Schroeder, C. Benedetti, E. Esarey, F. J. Grüner, and W. P. Leemans, Growth and phase velocity of self-modulated beam-driven plasma waves, Phys. Rev. Lett. 107, 145002 (2011).
  10. K. V. Lotov, G. Z. Lotova, V. I. Lotov, A. Upadhyay, T. Tückmantel, A. Pukhov, and A. Caldwell, Natural noise and external wakefield seeding in a proton-driven plasma accelerator, Phys. Rev. ST Accel. Beams 16, 041301 (2013).
  11. L. Verra et al. (AWAKE Collaboration), Controlled growth of the self-modulation of a relativistic proton bunch in plasma, Phys. Rev. Lett. 129, 024802 (2022).
  12. F. Batsch et al. (AWAKE Collaboration), Transition between instability and seeded self-modulation of a relativistic particle bunch in plasma, Phys. Rev. Lett. 126, 164802 (2021).
  13. K. V. Lotov, Physics of beam self-modulation in plasma wakefield accelerators, Phys. Plasmas 22, 103110 (2015).
  14. A. Pukhov, N. Kumar, T. Tückmantel, A. Upadhyay, K. Lotov, P. Muggli, V. Khudik, C. Siemon, and G. Shvets, Phase velocity and particle injection in a self-modulated proton-driven plasma wakefield accelerator, Phys. Rev. Lett. 107, 145003 (2011).

  15. With an electron beam energy of  ≈20  MeV and Eseed≈10  MV/m, Lseed∼2  m.

  16. A. Clairembaud et al. (AWAKE Collaboration), Measurement of the saturation length of the self-modulation instability, arXiv:2602.16624.
  17. R. Keinigs and M. E. Jones, Two-dimensional dynamics of the plasma wakefield accelerator, Phys. Fluids 30, 252 (1987).
  18. G. Demeter, J. T. Moody, M. Á. Kedves, F. Batsch, M. Bergamaschi, V. Fedosseev, E. Granados, P. Muggli, H. Panuganti, and G. Zevi Della Porta, Generation of 10-m-lengthscale plasma columns by resonant and off-resonant laser pulses, Opt. Laser Technol. 168, 109921 (2024).
  19. V. Fedosseev et al., Proc. int. part. acc. conf. (IPAC’16), in Proc. Int. Part. Acc. Conf. (2016).
  20. L. Verra et al. (AWAKE Collaboration), Filamentation of a relativistic proton bunch in plasma, Phys. Rev. Lett. 109, 055203 (2024).
  21. K. Rieger, A. C. Caldwell, P. Muggli, and O. Reimann. Streak Cameras and Optical Transition Radiation as a Diagnostic for Self-Modulation of Charged Particle Beams in Plasmas, Master’s Thesis, Technical University, Munich, 2014.

  22. With an initial timing of tRIFopt, the laser pulse reaches 2σt,s ahead of the electron beam centre after propagating over Lseed. This setting resulted in the fastest defocusing along the proton bunch [Fig. 5] from all tried settings.

  23. It is noted that the self-field of the electron bunch is not sufficient to ionise rubidium vapour or further ionise rubidium ions.

  24. P. Muggli, M. Bergamaschi, J. Pucek, D. Easton, J. Pisani, and J. Uncles, Plasma light as diagnostic for wakefields driven by developing self-modulation of a long particle bunch, in Proc. Adv. Acc. Conf. (AAC2022) (2022).
  25. AWAKE Collaboration, Experimental observation of proton bunch modulation in a plasma at varying plasma densities, Phys. Rev. Lett. 122, 054802 (2019).
  26. Y. Kim et al., Commissioning of the electron injector for the awake experiment, Nucl. Instrum. Methods Phys. Res., Sect. A 953, 163194 (2020).
  27. K. Pepitone et al., The electron accelerators for the awake experiment at CERN—baseline and future developments, Nucl. Instrum. Methods Phys. Res., Sect. A 909, 102 (2018).
  28. J. S. Schmidt et al., Status of the proton and electron transfer lines for the awake experiment at CERN, Nucl. Instrum. Methods Phys. Res., Sect. A 829, 58 (2016).
  29. N. Z. van Gils, M. Turner, G. Z. Della Porta, V. Bencini, E. Gschwendtner, L. Ranc, F. Pannell, and A. Gerbershagen, Preparation for realisation of external electron injection for awake run 2b, in Proceedings of the International Particle Accelerator Conference (IPAC’24) (JACoW Publishing, Geneva, Switzerland, 2024), pp. 549–552.
  30. M. Turner and P. Muggli, Understanding time-resolved images of awake proton bunches, J. Phys.:Conf. Ser. 3124, 012007 2024).
  31. C. R. Harris et al., Array programming with NumPy, Nature (London) 585, 357 (2020).
  32. M. Turner et al. (AWAKE Collaboration), Experimental observation of the motion of ions in a resonantly driven plasma wakefield accelerator, Phys. Rev. Lett. 134, 155001 (2025).
  33. J. Vieira, W. B. Mori, and P. Muggli, Hosing instability suppression in self-modulated plasma wakefields, Phys. Rev. Lett. 112, 205001 (2014).
  34. M. Moreira, P. Muggli, and J. Vieira, Mitigation of the onset of hosing in the linear regime through plasma frequency detuning, Phys. Rev. Lett. 130, 115001 (2023).

Outline

Information

Phys. Rev. Accel. Beams 29, 083601– Published 31 August, 2026
  • Received 31 March 2026
  • Accepted 20 July 2026
Crossmark - Check for updates button
Creative Commons Logo

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation