Segmented terahertz electron accelerator and manipulator (STEAM)


Acceleration and manipulation of electron bunches underlie most electron and X-ray devices used for ultrafast imaging and spectroscopy. New terahertz-driven concepts offer orders-of-magnitude improvements in field strengths, field gradients, laser synchronization and compactness relative to conventional radiofrequency devices, enabling shorter electron bunches and higher resolution with less infrastructure while maintaining high charge capacities (pC), repetition rates (kHz) and stability. We present a segmented terahertz electron accelerator and manipulator (STEAM) capable of performing multiple high-field operations on the six-dimensional phase space of ultrashort electron bunches. With this single device, powered by few-microjoule, single-cycle, 0.3 THz pulses, we demonstrate record terahertz acceleration of >30 keV, streaking with <10 fs resolution, focusing with >2 kT m–1 strength, compression to ~100 fs as well as real-time switching between these modes of operation. The STEAM device demonstrates the feasibility of terahertz-based electron accelerators, manipulators and diagnostic tools, enabling science beyond current resolution frontiers with transformative impact.

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Fig. 1: Experimental setup.
Fig. 2: Concept and implementation.
Fig. 3: Terahertz acceleration.
Fig. 4: Terahertz-driven electron pulse compression.
Fig. 5: Terahertz lens for electron pulse focusing and defocusing.
Fig. 6: Terahertz streak camera.

Change history

  • 24 April 2018

    In the pdf version of this Article originally published, ref. 32, although correctly cited, was missing from the main reference list and instead listed in error at the end of the Methods section. This has now been corrected.


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We gratefully acknowledge helpful discussions with C. Zhou, W. R. Huang, F. Ahr and W. Qiao, the expert technical support of T. Tilp, and M. Schust for fabrication of the STEAM devices used in this work. Besides Deutsches Elektronen Synchrotron (DESY) and the Helmholtz Association, this work was supported by the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) through the Synergy Grant ‘Frontiers in Attosecond X-ray Science: Imaging and Spectroscopy’ (AXSIS) (609920) and the excellence cluster ‘The Hamburg Center for Ultrafast Imaging – Structure, Dynamics and Control of Matter at the Atomic Scale’ (CUI, DFG-EXC1074), the priority programme ‘Quantum Dynamics in Tailored Intense Fields’ (QUTIF) (SPP1840 SOLSTICE) of the Deutsche Forschungsgemeinschaft and the accelerator on a chip programme (ACHIP) funded by the Gordon and Betty Moore Foundation (GBMF4744). The authors also thank T. Y. Fan and J. Zayhowski from MIT Lincoln Laboratory for initial work on the cryogenic Yb:YLF laser within the AXIS Program funded by the Defense Advanced Research Projects Agency (DARPA) and DARPA for the loan of the laser. X.W. acknowledges support through a Georg Forster Research Fellowship of the Alexander von Humboldt Foundation and A.-L.C through a Helmholtz Postdoctoral Fellowship from the Helmholtz Association.

Author information

F.X.K., D.Z., A.F. and N.H.M. conceived and coordinated the terahertz-driven electron acceleration and manipulation project. The structure was designed by A.F. and M.F. D.Z. designed the experimental setup and carried out the experiments. M.H., L.E.Z. and Y.H. built the Yb:YLF laser. A.-L.C. built the Yb:KYW laser with the help of H.C. X.W. and D.Z. built the terahertz setup. D.Z. built the ultraviolet generation and automated the setup. A.F. performed all simulations. A.-L.C., H.C., M.H., Y.H. and L.E.Z. maintained the laser systems and contributed with helpful discussions on the experiment. D.Z., A.F., N.H.M. and F.X.K. wrote the manuscript with revisions by all.

Correspondence to Dongfang Zhang.

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Supplementary Information

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Supplementary Video 1

THz field development as a function of time inside the STEAM device.

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Zhang, D., Fallahi, A., Hemmer, M. et al. Segmented terahertz electron accelerator and manipulator (STEAM). Nature Photon 12, 336–342 (2018).

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