Demonstration of a 10-metre-long discharge plasma source for plasma wakefield acceleration

C. Amoedo; N. Lopes; N. E. Torrado; F. Silva; P. Muggli; L. Verra; M. Turner; G. Zevi Della Porta; M. Bergamaschi; A. Clairembaud; J. Mezger; F. Pannell; N. Z. van Gils; E. Gschwendtner; A. Sublet; the AWAKE Collaboration

arXiv · 2609.08551

Demonstration of a 10-metre-long discharge plasma source for plasma wakefield acceleration

C. Amoedo·N. Lopes·N. E. Torrado·F. Silva·P. Muggli·L. Verra·M. Turner·G. Zevi Della Porta·M. Bergamaschi·A. Clairembaud·J. Mezger·F. Pannell·N. Z. van Gils·E. Gschwendtner·A. Sublet·the AWAKE Collaboration

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Abstract

The AWAKE experiment at CERN uses high-energy proton bunches to drive plasma wakefields capable of accelerating electron bunches up to hundreds of GeV in a single plasma. Realising this potential requires a plasma source that can extend to tens of metres while maintaining high longitudinal uniformity and reproducibility. Towards this goal, we report on the first experimental characterisation and beam-based validation of a 10-metre-long pulsed-DC discharge plasma source (DPS) used as an alternative to the laser-ionised rubidium vapour plasma source (VPS). The DPS reliably delivered plasma densities in three noble gases (He, Ar, Xe) at electron densities between 10$^{14}$ and 10$^{15}$ cm$^{-3}$. Proton bunch self-modulation was observed with all three gases, and the resulting modulation frequency was used as a beam-based diagnostic of the plasma density, showing good agreement with laboratory interferometry measurements. The event-to-event modulation frequency was demonstrated to be reproducible to within 0.63%, comparable to that of the VPS. These results establish the DPS as a valid alternative plasma source for beam-driven wakefield experiments, and support its further development towards longer plasma lengths. The present design is tailored to AWAKE requirements, but the underlying discharge concept provides a route to long, reproducible plasma sources with straightforward density control through discharge-beam timing for other beam-plasma experiments.

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C. Amoedo, N. Lopes, N. E. Torrado, F. Silva, P. Muggli, L. Verra, M. Turner, G. Zevi Della Porta, M. Bergamaschi, A. Clairembaud, J. Mezger, F. Pannell, N. Z. van Gils, E. Gschwendtner, A. Sublet, the AWAKE Collaboration. 2026-09-08. Demonstration of a 10-metre-long discharge plasma source for plasma wakefield acceleration. https://arxiv.org/abs/2609.08551

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