%0 Thesis
%A Gonzalez Caminal, Pau
%T Time-Resolved Phase-Space Characterisation of Plasma-Wakefield-Accelerated Electrons at FLASHForward
%N DESY-THESIS-2022-014
%I Universität Hamburg
%V Dissertation
%C Hamburg
%M PUBDB-2022-03578
%M DESY-THESIS-2022-014
%B DESY-THESIS
%P 262
%D 2022
%Z Dissertation, Universität Hamburg, 2022
%X A plasma can sustain electric fields orders of magnitude larger than those attainable with the conventional radio-frequency (RF) technology typically used in particle accelerators, which are limited to ∼ 100 MV/m due to electrical breakdowns occurring at the metallic boundary of the accelerating structures. In a particle-beam-driven plasma-wakefield accelerator (PWFA), a charge-density wake sustaining field gradients in excess of GV/m is driven by the passage of a relativistic high-intensity particle bunch through a plasma. By harnessing the gradientsof the wake, particles trailing behind the wakefield-driving bunch can be accelerated to GeV energies over meter distances, thus enabling a drastic reduction of the size of acceleratorcomponenents and, consequently, potentially reducing the costs of future accelerator facilities. Despite this promise, however, for PWFA to be a viable technology, the quality of theaccelerated bunches must match that achieved by RF-based state-of-the-art FEL linacs and particle colliders. Even though theoretical predictions suggest that PWFA schemes are capable of producing electric-field profiles with properties sufficient to preserve the longitudinal-phase-space structure of the accelerating beam, direct experimental demonstration has not yet been achieved.In the work presented in this thesis the diagnostic capabilities of a novel X-band transverse deflection structure (TDS)—featuring femtosecond resolution and a variablepolarisation of the streaking field—are exploited to investigate two mechanisms enabling the preservation of the energy spread of electron beams accelerated in a nonlinear plasma wake: optimal beam loading to preserve the correlated energy spread and a fully evacuated ion column to preserve the uncorrelated energy spread. By directly observing the longitudinal phase space of 1-GeV bunches accelerated 44 MeV in a nonlinear plasma wake, experiments performed at the FLASHForward facility (DESY, Hamburg) demonstrate that the longitudinal accelerating gradients are transversely homogeneous to within 0.8 
%F PUB:(DE-HGF)3 ; PUB:(DE-HGF)11
%9 BookDissertation / PhD Thesis
%R 10.3204/PUBDB-2022-03578
%U https://bib-pubdb1.desy.de/record/480259