Multi-Joule Energy Transfer and Total Charge Capture in a Laser-ionized Plasma Wakefield Accelerator

Plasma wakefield accelerators (PWFA) offer acceleration gradients orders of magnitude higher than those achievable with conventional radiofrequency accelerators. For collider applications, critical requirements include the transfer of 10–100 J of energy from the drive beam to the plasma, high drive-to-wake energy transfer efficiency, overall energy efficiency, and preservation of the witness beam’s charge and quality. Using a laser-ionized hydrogen plasma source, we demonstrate significant progress toward meeting these benchmarks. In a single-bunch configuration, we achieve at least 5.6 J of energy transfer from a 1.52 nC, 10 GeV electron beam to a plasma with density 4.5×10¹⁶ cm⁻³, while achieving at least 37±3% drive-to-wake energy transfer efficiency. In a two-bunch experiment, we demonstrate—for the first time at high energy—complete charge capture of an externally injected 300pC witness beam, while maintaining high overall energy efficiency.