Speaker
Description
An intense electron beam can excite extreme plasmons that are non-perturbative oscillations of conduction band electrons [Sahai, Adv. Quant. Tech., 8, 2500037 (2025)]. The resulting large-amplitude oscillations can access fields as high as Petavolts per meter owing to quantum coherence when excited by a sufficiently intense particle beam propagating in a tube fabricated in condensed matter. This underlies the concept of nano-plasmonic accelerator and wiggler [Sahai, IEEE Access, 9, 54831-39 (2021)].
However, such excitation requires carefully controlled interaction [Sahai et al., IEEE Access, 11, 476–493 (2023)], especially mitigating collisions that seed various instabilities as well as matching the properties of the quantum gas and tube structure with that of the beam to optimize energy transfer. In our ongoing experiment E-339 at SLAC, we have demonstrated this control for the first time. This has resulted in the unprecedented observation of ten GV/m-gradient in condensed matter system using crunch-in plasmon excited by 10GeV FACET-II electron beam of few tens of micron overall dimensions aligned with tens of micron tubes of appropriately tuned electronic and material properties [Sahai, A. A., et al., proc of IPAC’26 (2026)].
In this work, we present the techniques that have been developed for pre-requisite high precision alignment using optical laser and electron beam. We show that the 2D Fourier transform of tube aperture provides a robust and sensitive signature of axial propagation of HeNe laser, enabling ten-micron level pre alignment. Subsequent beam-based scans refine the alignment to the micron level using gamma-ray signatures. We report results from recent campaigns at FACET II, demonstrating the reliability and reproducibility of this method, establishing E-339 on a strong foundation.
| Working group | WG4 |
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