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@PHDTHESIS{PenaAsmus:626056,
      author       = {Pena Asmus, Felipe Lars},
      othercontributors = {Hillert, Wolfgang and Lindstroem, Carl Andreas},
      title        = {{D}emonstration of {H}igh {E}nergy-{T}ransfer {E}fficiency
                      for {Q}uality-{P}reserving, {B}eam-{D}riven
                      {P}lasma-{W}akefield {A}ccelerators},
      school       = {University of Hamburg},
      type         = {Dissertation},
      reportid     = {PUBDB-2025-01278},
      pages        = {150},
      year         = {2024},
      note         = {Dissertation, University of Hamburg, 2024},
      abstract     = {With the advancement of climate change, greenhouse gas
                      emissions in all aspects of society must be reduced,
                      including research. Particle collider and free-electron
                      laser (FEL) facilities have become increasingly large as
                      their scientific reach has been extended by using
                      higher-energetic particles. While they have proven
                      indispensable in fundamental research and industry and have
                      impelled technological advances, they also have a large
                      environmental footprint.Plasma accelerators, which
                      accelerate particle bunches in the wakefields of a charged
                      bunch propagating through a plasma, can sustain
                      orders-of-magnitude-greater accelerating gradients than
                      state-of-the-art accelerators. This would shrink the size of
                      collider and FEL facilities, reducing their
                      construction-arising environmental footprint and costs.
                      However, a large fraction of the carbon footprint across the
                      lifetime of such high-beam-power machines comes from power
                      consumption during operation. Plasma accelerators must
                      operate at high energy-transfer efficiency to ensure that
                      the benefits of a smaller facility are not rendered futile
                      by excessive power consumption. This thesis treats the topic
                      of energy efficiency in plasma accelerators, presenting
                      experimental results with high energy efficiency in the two
                      transfers occurring within the plasma: from the driving
                      bunch to the plasma and from the plama to the accelerating
                      bunch. However, these types of facilities require
                      high-quality bunches. Therefore, the experimental results
                      must also be relevant for quality-preserving
                      acceleration.Measuring high-quality bunches and a high
                      energy-transfer efficiency requires precise diagnostics, for
                      which a detailed dipole spectrometer calibration is
                      performed. This allowed demonstrating experimentally the
                      acceleration of a particle bunch at 0.8 GV/m while
                      preserving its energy spread, charge, and transverse
                      emittance. The plasma-to-accelerating-bunch energy-transfer
                      efficiency in this first quality-preserving working point is
                      $22\%,$ close to the literature’s record efficiencies.The
                      main result of this thesis is the experimental demonstration
                      of (59 ± $3)\%$ driver-to-plasma energy-transfer efficiency
                      – an order of magnitude larger than previous results in
                      the literature. This result was achieved at the limit of
                      re-acceleration, a process that would hinder preserving the
                      quality of an accelerating bunch, where the first driver
                      electrons become non-relativistic, slip backward in phase
                      and get re-accelerated. For the first time, this process,
                      which limits the energy efficiency of a plasma accelerator,
                      is measured in detail and with two separate
                      diagnostics.While the high efficiency of these results was
                      achieved separately, they represent key milestones in
                      demonstrating high-efficiency and quality-preserving plasma
                      accelerators.},
      cin          = {MPA},
      cid          = {I:(DE-H253)MPA-20200816},
      pnm          = {621 - Accelerator Research and Development (POF4-621) /
                      PHGS, VH-GS-500 - PIER Helmholtz Graduate School
                      $(2015_IFV-VH-GS-500)$},
      pid          = {G:(DE-HGF)POF4-621 / $G:(DE-HGF)2015_IFV-VH-GS-500$},
      experiment   = {EXP:(DE-MLZ)NOSPEC-20140101},
      typ          = {PUB:(DE-HGF)11},
      urn          = {urn:nbn:de:gbv:18-ediss-119070},
      doi          = {10.3204/PUBDB-2025-01278},
      url          = {https://bib-pubdb1.desy.de/record/626056},
}