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@ARTICLE{Ying:610878,
      author       = {Ying, Jianwei and He, Xie and Su, Dace and Zheng, Lingbin
                      and Kroh, Tobias and Rohwer, Timm and Fakhari, Moein and
                      Kassier, Günther H. and Ma, Jingui and Yuan, Peng and
                      Matlis, Nicholas H. and Kärtner, Franz X. and Zhang,
                      Dongfang},
      title        = {{H}igh gradient terahertz-driven ultrafast photogun},
      journal      = {Nature photonics},
      volume       = {18},
      number       = {7},
      issn         = {1749-4885},
      address      = {London [u.a.]},
      publisher    = {Nature Publ. Group},
      reportid     = {PUBDB-2024-04712},
      pages        = {758-765},
      year         = {2024},
      abstract     = {Terahertz (THz)-based electron acceleration has potential
                      as a technology for next-generation cost-efficient compact
                      electron sources. Although proof-of-principle demonstrations
                      have proved the feasibility of many THz-driven accelerator
                      components, THz-driven photoguns with sufficient brightness,
                      energy and control for use in demanding ultrafast
                      applications have yet to be achieved. Here we present a
                      novel millimetre-scale multicell waveguide-based THz-driven
                      photogun that exploits field enhancement to boost the
                      electron energy, a movable cathode to achieve precise
                      control over the accelerating phase as well as multiple
                      cells for exquisite beam control. The short driving
                      wavelength enables a peak acceleration gradient as high as
                      ~3 GV m−1. Using microjoule-level single-cycle THz
                      pulses, we demonstrate electron beams with up to ~14 keV
                      electron energy, $1\%$ energy spread and ~0.015 mm mrad
                      transverse emittance. With a highly integrated rebunching
                      cell, the bunch is further compressed by about ten times to
                      167 fs with ~10 fC charge. High-quality diffraction
                      patterns of single-crystal silicon and projection microscopy
                      images of the copper mesh are achieved. We are able to
                      reveal the transient radial electric field developed from
                      the charged particles on a copper mesh after photoexcitation
                      with high spatio-temporal resolution, providing a potential
                      scheme for plasma-based beam manipulation. Overall, these
                      results represent a new record in energy, field gradient,
                      beam quality and control for a THz-driven electron gun,
                      enabling real applications in electron projection microscopy
                      and diffraction. This is therefore a critical step and
                      milestone in the development of all-optical THz-driven
                      electron devices, validating the maturity of the technology
                      and its use in precision applications.},
      cin          = {FS-CFEL-2},
      ddc          = {530},
      cid          = {I:(DE-H253)FS-CFEL-2-20120731},
      pnm          = {631 - Matter – Dynamics, Mechanisms and Control
                      (POF4-631) / DFG project G:(GEPRIS)194651731 - EXC 1074:
                      Hamburger Zentrum für ultraschnelle Beobachtung (CUI):
                      Struktur, Dynamik und Kontrolle von Materie auf atomarer
                      Skala (194651731) / AIM, DFG project G:(GEPRIS)390715994 -
                      EXC 2056: CUI: Advanced Imaging of Matter (390715994)},
      pid          = {G:(DE-HGF)POF4-631 / G:(GEPRIS)194651731 /
                      G:(GEPRIS)390715994},
      experiment   = {EXP:(DE-H253)AXSIS-20200101},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:001222564100001},
      doi          = {10.1038/s41566-024-01441-y},
      url          = {https://bib-pubdb1.desy.de/record/610878},
}