Author: Zhang, Z.
Paper Title Page
Development of Two-Color Sub-Femtosecond Pump/Probe Techniques with X-Ray Free-Electron Lasers  
  • Z.H. Guo, P.L. Franz
    Stanford University, Stanford, California, USA
  • D.B. Cesar, J.P. Cryan, T.D.C. Driver, J.P. Duris, Z. Huang, K. Larsen, S. Li, A. Marinelli, J.T. O’Neal, R. Robles, N.S. Sudar, A.L. Wang, Z. Zhang
    SLAC, Menlo Park, California, USA
  Funding: This work is supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences (BES), Accelerator and Detector research program.
We report the generation of GW-level attosecond pump/probe pulse pairs with tunable sub-femtosecond delays at the Linac Coherent Light Source (LCLS). The attosecond 370 eV pump pulse is first generated via the Enhanced Self-Amplified Spontaneous Emission (ESASE) method, then the attosecond 740 eV probe pulse is produced by re-amplifying the electron beam microbunching after the magnetic chicane. Due to the harmonic amplification, the minimal delay between pump-probe pulse pairs (limited by slippage between the light field and the electron bunch) can be shorter than 1 femtosecond. We use the angular streaking technique to measure temporal delays between pump/probe pulse pairs at multiple beamline configurations. When the delay chicane is turned off, the averaged delay is increased by ~150 attoseconds by adding one undulator module for probe pulses. Long delays can be set up by turning the delay chicane on. These experimental results are in agreement with start-to-end XFEL simulations. Looking toward future experiments, our sub-femtosecond pump/probe technique can be applied to observe electronic charge dynamics in molecular systems.
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THYE3 Superconducting Undulators and Cryomodules for X-ray Free-Electron Lasers 870
  • D.C. Nguyen, G.J. Bouchard, B.M. Dunham, G.L. Gassner, Z. Huang, E.M. Kraft, P. Krejcik, M.A. Montironi, H.-D. Nuhn, T.O. Raubenheimer, Z.R. Wolf, Z. Zhang
    SLAC, Menlo Park, California, USA
  • J.M. Byrd, J.D. Fuerst, E. Gluskin, Y. Ivanyushenkov, M. Kasa, E.R. Moog, M.F. Qian, Y. Shiroyanagi
    ANL, Lemont, Illinois, USA
  Funding: Work supported by the US DOE Office of Science, Basic Energy Sciences, Office of Accelerator and Detector Research (Manager: Dr. Eliane Lessner).
We present connectable designs of superconducting undulators (SCU) and cryomodules (CM) based on previous SCU and CM designs at Argonne National Lab. The new SCU and CM designs will allow us to connect one CM to the next to form a contiguous line of SCUs with no breaks between the cryomodules. The SCU design will have correctors and phase shifters integrated into the main SCU magnet core, as well as external corrector magnets for trajectory corrections. There will also be a cryogenic magnetic quadrupole and a cold RF beam position monitor (BPM) integrated in the SCU CM. In addition to providing the usual FODO transverse focusing, the quadrupole and BPM will be used for the beam-based alignment technique that is critical for X-ray FEL operation. In this paper, we will present the conceptual design of the new SCU CM as well as results of FEL simulations using the SCUs as afterburners for the LCLS hard X-ray undulators.
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DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-THYE3  
About • Received ※ 02 August 2022 — Revised ※ 07 August 2022 — Accepted ※ 08 August 2022 — Issue date ※ 16 August 2022
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