Plasma-Wakefield Accelerator Simultaneously Boosts Electron Beam Energy and Brightness

Abstract: High-energy particle colliders and X-ray free-electron lasers demand electron beams with qualities currently achieved only in kilometer-scale radio-frequency accelerators. Plasma accelerators promise a compact alternative but have faced challenges in delivering the needed beam quality at relevant energies. Here, we demonstrate a plasma-wakefield accelerator operating in the nonlinear regime that acts as a transformer to simultaneously boost the energy and brightness of an electron bunch injected from the plasma. Using a 10-GeV drive bunch and a three-stage meter-scale plasma source, we generated electron bunches exceeding 20 GeV with sub-percent energy spread, 2 mm·mrad normalized emittance, and multi-kA peak current. A significant number of drive-bunch electrons lost over 90% of their energy, a prerequisite for high energy-conversion efficiency. This demonstration of an energy transformer ratio exceeding two and a brightness enhancement over an order of magnitude opens a path towards cost-effective accelerators for future colliders and light sources.

Recommended citation: Chaojie Zhang, Douglas Storey, Alexander Knetsch, Brendan O’Shea, Robert Ariniello, Gevy J. Cao, Sebastien Corde, Thamine N. Dalichaouch, Claudio Emma, Ole G. Finnerud, Spencer Gessner, Claire Hansel, Elias Hansen, Valentina Lee, Carl A. Lindstrom, Mike Litos, Nathan Majernik, Kenneth A. Marsh, Warren B. Mori, Ivan Rajkovic, Mark J. Hogan, and Chan Joshi, "Plasma-Wakefield Accelerator Simultaneously Boosts Electron Beam Energy and Brightness," Nat. Communications. (2025).
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