Author: Kearney, S.P.
Paper Title Page
MOP001 Diamond Double-Crystal System for a Forward Bragg Diffraction X-Ray Monochromator of the Self-Seeded PAL XFEL 1
 
  • Yu. Shvyd'ko, J.W.J. Anton, S.P. Kearney, K.-J. Kim, T. Kolodziej, D. Shu
    ANL, Argonne, Illinois, USA
  • V.D. Blank, S. Terentiev
    TISNCM, Troitsk, Russia
  • H.-S. Kang, C.-K. Min, B.G. Oh
    PAL, Pohang, Kyungbuk, Republic of Korea
  • P. Vodnala
    Northern Illinois University, DeKalb, Illinois, USA
 
  An x-ray monochromator for a hard x-ray self-seeding system is planned at PAL XFEL to be used in a 3-keV to 10-keV photon spectral range. The monochromatization in a 5 keV to 7 keV range will be achieved by forward Bragg diffraction (FBD) from a 30-micron-thin diamond crystal in the [110] orientation employing the (220) symmetric Bragg reflection. FBD from the same crystal using the (111) asymmetric Bragg reflection will provide monochromatization in a 3 keV to 5 keV spectral range. In the 7-keV to 10-keV spectral range, a 100-micron crystal in the [100] orientation will be used employing FBD with the (400) symmetric Bragg reflection. Two almost defect-free diamond crystals in the required orientations and thicknesses are mounted in a strain-free mechanically-stable fashion on a common CVD diamond substrate using all-diamond components, ensuring radiation-safe XFEL operations with improved heat transport. We will present results of the optical and engineering designs, manufacturing, and x-ray diffraction topography characterization of the diamond double-crystal system.  
 
MOP056 Design of Apparatus for a High-Power-Density Diamond Irradiation Endurance Experiment for XFELO Applications 1
 
  • S.P. Kearney, K.-J. Kim, T. Kolodziej, R.R. Lindberg, D. Shu, Yu. Shvyd'ko, D. Walko, J. Wang
    ANL, Argonne, Illinois, USA
  • S. Stoupin
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
We have designed a diamond irradiation setup capable of achieving multiple kW/mm2 power density. The setup was installed at the 7-ID-B beamline at the Advanced Photon Source (APS) for a successful irradiation experiment, testing the capability of diamond to endure x-ray free electron laser oscillator (XFELO) levels of irradiation (≥ 10 kW/mm2) without degradation of Bragg reflectivity.* Focused white-beam irradiation (50 μm x 20 μm spot size at 12.5 kW/mm2 power density) of a diamond single crystal was conducted in a vacuum environment of 1x10-8 Torr for varying durations of time at different spots on the diamond, and also included one irradiation spot during a spoiled vacuum environment of 4x10-6 Torr. Here we present the apparatus used to irradiate the diamond consisting of multiple subassemblies: the fixed masks, focusing optics, gold-coated UHV irradiation chamber, water-cooled diamond holder, chamber positioning stages (with sub-micron resolution) and detector.
* T. Kolodziej et al., Free Electron Laser Conf. 2017.
 
 
MOP057
Diamond Endurance to Irradiation with X-ray Beams of Multi kW/mm2 Power Densities for XFELO Application  
 
  • T. Kolodziej, T. Gog, S.P. Kearney, K.-J. Kim, W. Liu, A. Said, D. Shu, Yu. Shvyd'ko, D. Walko, J. Wang
    ANL, Argonne, Illinois, USA
  • M. Baldini, W. Yang
    High Pressure Synergic Consortium, Advanced Photon Source, Lemont, USA
  • V.D. Blank, S. Terentiev
    TISNCM, Troitsk, Russia
  • P. Rigg
    Dynamic Compression Sector, Washington State University, Lemont, USA
  • S. Stoupin
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
 
  Funding: Work at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357
X-ray science has recently been considerably shaped by the advent of modern bright and powerful x-ray sources: 3rd generation synchrotron radiation storage rings and XFELs. XFELs in the oscillator configuration (XFELO) are possible future new sources, in which x-ray beams generated by the undulator circulate in an optical x-ray cavity comprised of high-reflectance (close to 100%) diamond crystal mirrors working in Bragg backscattering. XFELOs will produce stable, fully coherent hard x-rays of ultra-high (meV) spectral purity. The average power density of the x-ray beams in the XFELO cavity is however predicted to be unprecedentedly high, about ≈15 kW/mm2. Therefore, the XFELO feasibility relies on the ability of diamond to withstand such a high radiation load and preserve its high reflectivity. We are reporting on endurance studies of the highest-quality, practically flawless synthetic diamond crystals to irradiation with power density close to that expected on the XFELO crystals. Most importantly, we are studying whether the extremely high Bragg reflectivity of meV-monochromatic x-rays from the diamond crystals in backscattering is conserved after the irradiation.
 
 
TUC03
High-Flux, Fully Coherent X-Ray FEL Oscillator  
 
  • K.-J. Kim, S.P. Kearney, T. Kolodziej, R.R. Lindberg, X. Shi, D. Shu, Yu. Shvyd'ko
    ANL, Argonne, Illinois, USA
  • K.L.F. Bane, Y. Ding, P. Emma, W.M. Fawley, J.B. Hastings, Z. Huang, J. Krzywinski, G. Marcus, T.J. Maxwell
    SLAC, Menlo Park, California, USA
  • V.D. Blank, S. Terentiev
    TISNCM, Troitsk, Russia
  • W.M. Fawley
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • C. Grizolli
    LNLS, Campinas, Brazil
  • W. Qin
    PKU, Beijing, People's Republic of China
  • S. Stoupin
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • J. Zemella
    DESY, Hamburg, Germany
 
  Funding: The ANL part of this work is supported by the U.S. DOE Office of Science under Contract No. DE-AC02-06CH11357 and the SLAC part under contract No. DE-AC02-76SF00515.
By optimizing the parameters of the accelerator, undulator, and the optical cavity, an XFELO driven by an 8-GeV superconducting linac is predicted to produce 10zEhNZeHn photons per pulse at the important photon energies around 14.4 keV.* This is an order of magnitude larger than that in previous designs.** With a BW of 3 meV (FWHM), rep rate of 1 MHz, and taking into account the full coherence, the spectral brightness is then 2×1026 photons per (mm2mr2 0.1\% BW), which is higher than any other source currently operating or anticipated in the future. Experiments at APS beam lines have shown that a high-quality diamond crystal can survive the power density (~15 kW/mm2) expected at the XFELO intra-cavity crystals preserving the high reflectivity.*** The compound refractive lenses can serve as the focusing element. Adding an XFELO to the suite of other FEL sources will, at a minor incremental cost but with a major scientific payoff, significantly expand the scientific capabilities at superconducting linac-based XFEL facilities, such as the European XFEL, the proposed LCLS-II High Energy upgrade and the XFEL project in Shanghai.
* W. Qin et al., this conference.
** R.R. Lindberg et al., Phys. Rev. ST Accel. Beams, vol 14, 403 (2011).
*** T. Kolodziej et al., this conference.