Single-Shot Characterization of High Transformer Ratio Wakefields in Nonlinear Plasma Acceleration

Abstract

Plasma wakefields can enable very high accelerating gradients for frontier high energy particle accelerators, in excess of 10 GeV/m. To overcome limits on total acceleration achievable, specially shaped drive beams can be used in both linear and nonlinear plasma wakefield accelerators (PWFA), to increase the transformer ratio, implying that the drive beam deceleration is minimized relative to acceleration obtained in the wake. In this Letter, we report the results of a nonlinear PWFA, high transformer ratio experiment using high-charge, longitudinally asymmetric drive beams in a plasma cell. An emittance exchange process is used to generate variable drive current profiles, in conjunction with a long (multiple plasma wavelength) witness beam. The witness beam is energy-modulated by the wakefield, yielding a response that contains detailed spectral information in a single-shot measurement. Using these methods, we generate a variety of beam profiles and characterize the wakefields, directly observing beam-loaded transformer ratios up to R=7.8. Furthermore, a spectrally-based reconstruction technique, validated by 3D particle-in-cell simulations, is introduced to obtain the drive beam current profile from the decelerating wake data.

References in corpus (4)

• Generation of Relativistic Electron Bunches with Arbitrary Current Distribution via Transverse-to-Longitudinal Phase Space Exchange
• Tailored electron bunches with smooth current profiles for enhanced transformer ratios in beam-driven acceleration
• Single-Shot Characterization of High Transformer Ratio Wakefields in Nonlinear Plasma Acceleration
• Spatial Control of Photoemitted Electron Beams using a Micro-Lens-Array Transverse-Shaping Technique

Cited by in corpus (12)

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• Single-Shot Characterization of High Transformer Ratio Wakefields in Nonlinear Plasma Acceleration
• Bunch Shaping in Electron Linear Accelerators
• Energy Depletion and Re-Acceleration of Driver Electrons in a Plasma-Wakefield Accelerator
• First emittance measurement of the beam-driven plasma wakefield accelerated electron beam
• Beam shaping using an ultra-high vacuum multileaf collimator and emittance exchange beamline
• Longitudinal current profile reconstruction from wakefield response in plasmas and structures
• Drive beam sources and longitudinal shaping techniques
• Progress in End-to-End Optimization of Detectors for Fundamental Physics with Differentiable Programming
• Correlations between X-rays, Visible Light and Drive-Beam Energy Loss Observed in Plasma Wakefield Acceleration Experiments at FACET-II
• Multileaf Collimator for Real-Time Beam Shaping using Emittance Exchange
• Single-shot Transverse Wakefield Mapping with a Hollow Electron Beam