Author: Bohler, D.K.
Paper Title Page
MOPOPT052 Beam-Based Alignment for LCLS-II CuS Linac-to-Undulator Quadrupoles 377
 
  • X. Huang, D.K. Bohler
    SLAC, Menlo Park, California, USA
 
  An advanced method for beam-based alignment that can simultaneously determine the quadrupole centers of multiple magnets has been applied to the LCLS-II CuS linac-to-undulator (LTU) section. The new method modulates the strengths of multiple quadrupoles and monitor the induced trajectory shift. Measurements are repeated with the beam trajectory through the quadrupoles steered with upstream correctors, from which the quadrupole centers can be obtained. Steering of the trajectory to minimize the induced trajectory shift is also done for finding the quadrupole centers.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT052  
About • Received ※ 27 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022
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TUPOPT044 High-Power Attosecond Pulses via Cascaded Amplification 1101
 
  • P.L. Franz, Z.H. Guo, S. Li, R. Robles
    Stanford University, Stanford, California, USA
  • D.K. Bohler, D.B. Cesar, X. Cheng, J.P. Cryan, T.D.C. Driver, J.P. Duris, A. Kamalov, S. Li, A. Marinelli, R. Obaid, R. Robles, N.S. Sudar, A.L. Wang, Z. Zhang
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by US Department of Energy Contracts No. DE-AC02-76SF00.
The timescale for electron motion in molecular systems is on the order of hundreds of attoseconds, and thus the time-resolved study of electronic dynamics requires a source of sub-femtosecond x-ray pulses. Here we report the experimental generation of sub-femtosecond duration soft x-ray free electron laser (XFEL) pulses with hundreds of microjoules of energy using fresh-slice amplification in two cascaded stages at the Linac Coherent Light Source. In the first stage, an enhanced self-amplified spontaneous emission (ESASE) pulse is generated using laser-shaping of the electron beam at the photocathode*. The electron bunch is then delayed relative to the pulse by a magnetic chicane, allowing the radiation to slip onto a fresh slice of the bunch, which amplifies the ESASE pulse in the second cascade stage. Angular streaking** characterizes the experimental pulse durations as sub-femtosecond at ~465 eV in the experiment.
* Zhang, Z. et al. New J. Phys. 22 (2020)
** Li, S. et al. Optics Express 26.4 (2018): 4531-4547.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT044  
About • Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 21 June 2022
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