Keyword: photon
Paper Title Other Keywords Page
MOBA02 Coherence Limits of X-ray FEL Radiation ion, FEL, radiation, electron 5
 
  • M.V. Yurkov, E. Schneidmiller
    DESY, Hamburg, Germany
 
  The most simple and robust technique for production of short wavelength radiation is Self Amplified Spontaneous Emission (SASE) FEL. Amplification process in SASE FELs develops from the shot noise in the electron beam, and powerful radiation is produced by single pass of the electron beam through the undulator. Serving as a seed, shot noise effects impose fundamental limits on the coherence properties of the radiation (both, temporal and spatial). FEL theory reached mature status allowing elegant description of the shot noise phenomena, and in this report we present relevant overview.  
slides icon Slides MOBA02 [2.606 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOBA02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOD06 Matter-Radiation Interactions in Extremes (MaRIE) Project Overview ion, FEL, electron, cavity 24
 
  • R.L. Sheffield, C.W. Barnes, J.P. Tapia
    LANL, Los Alamos, New Mexico, USA
 
  The National Nuclear Security Administration (NNSA) requires the ability to understand and test how material structures, defects and interfaces determine performance in extreme environments. The MaRIE Project will provide the science ability for control of materials and their production for vital national security missions. To meet the mission requirements, MaRIE must be an x-ray source that has high brilliance and with very flexible and fast pulses to observe phenomena at shock-relevant time scales, and with high enough energy to study high-Z materials. This talk will cover the rationale for the machine requirements, a pre-conceptual reference design that can meet those requirements, and preliminary research needed to address the critical high risk technologies.  
slides icon Slides MOD06 [3.461 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOD06  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOP001 Diamond Double-Crystal System for a Forward Bragg Diffraction X-Ray Monochromator of the Self-Seeded PAL XFEL ion, FEL, electron, laser 29
 
  • 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.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP001  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOP014 Harmonic Lasing Towards Shorter Wavelengths in Soft X-Ray Self-Seeding FELs ion, FEL, undulator, radiation 57
 
  • L. Zeng, S. Huang, K.X. Liu, W. Qin, G. Zhao
    PKU, Beijing, People's Republic of China
  • Y. Ding, Z. Huang
    SLAC, Menlo Park, California, USA
 
  In this paper, we study a simple harmonic lasing scheme to extend the wavelength of X-ray self-seeding FELs. The self-seeding amplifier is comprised of two stages. In the first stage, the fundamental radiation is amplified but well restricted below saturation, and simultaneously harmonic radiation is generated. In the second stage, the fundamental radiation is suppressed while the harmonic radiation is amplified to saturation. We performed a start-to-end simulation to demonstrate third harmonic lasing in a soft x-ray self-seeding FEL at the fundamental wavelength of 1.52 nm. Our simulations show that a stable narrow-band FEL at GW levels can be obtained.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP014  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOP033 Baseline Parameters of the European XFEL ion, FEL, undulator, electron 109
 
  • E. Schneidmiller, M.V. Yurkov
    DESY, Hamburg, Germany
 
  We present the latest update of the baseline parameters of the European XFEL. It is planned that the electron linac will operate at four fixed electron energies of 8.5, 12, 14, and 17.5 GeV. Tunable gap undulators provide the possibility to change the radiation wavelength in a wide range. Operation with different bunch charges (0.02, 0.1, 0.25, 0.5 and 1 nC) provides the possibility to operate XFEL with different radiation pulse duration. We also discuss potential extension of the parameter space which does not require new hardware and can be realized at a very early stage of the European XFEL operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP033  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOP037 Opportunities for Two-Color Experiments at the SASE3 Undulator Line of the European XFEL ion, electron, FEL, undulator 121
 
  • S. Serkez, G. Geloni, T. Mazza, M. Meyer
    XFEL. EU, Schenefeld, Germany
  • V. Kocharyan, E. Saldin
    DESY, Hamburg, Germany
 
  As is well known, the installation of a simple magnetic chicane in the baseline undulator of an XFEL allows for producing two-color FEL pulses. In this work we discuss the possibility of applying this simple and cost-effective method at the SASE3 soft X-ray beamline of the European XFEL. We consider upgrades of this method that include the further installation of a mirror chicane. We also discuss the scientific interest of this upgrade for the Small Quantum Systems (SQS) instrument, in connection with the high-repetition rate of the European XFEL, and we provide start-to-end simulations up to the radiation focus on the sample, proving the feasibility of our concept. Our proposed setup has been recently funded by the Finnish Research Infrastructure (FIRI) and will be built at SASE3 in 2020-2021.  
poster icon Poster MOP037 [1.849 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP037  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOP038 Overview of the Soft X-Ray Line Athos at SwissFEL ion, undulator, FEL, electron 125
 
  • R. Ganter, S. Bettoni, H.-H. Braun, M. Calvi, P. Craievich, R. Follath, C.H. Gough, F. Löhl, M. Paraliev, L. Patthey, M. Pedrozzi, E. Prat, S. Reiche, T. Schmidt, A.Z. Zandonella
    PSI, Villigen PSI, Switzerland
 
  The Athos line will cover the photon energy range from 250 to 1900 eV and will operate parallel to the hard x-ray line Aramis of SwissFEL. Athos consists of fast kicker magnets, a dog-leg transfer line, a small linac and 16 APPLE undulators. The Athos undulators follow a new design: the so-called APPLE X design where the 4 magnet arrays can be moved radially in a symmetric way. Besides mechanical advantages of such a symmetric distribution of forces, this design allows for easy photon energy scans at a constant polarization or for the generation of transverse magnetic gradients. Another particularity of the Athos FEL line is the inclusion of a short magnetic chicane between every undulator segment. These chicanes will allow the FEL to operate in optical klystron mode, high-brightness SASE mode, or superradiance mode. A larger delay chicane will split the Athos line into two sections such that two colors can be produced with adjustable delay. Finally a post undulator transverse deflecting cavity will be the key tool for the commissioning of the FEL modes. The paper will present the current status of this four years project started in 2017.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP038  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOP044 Commissioning Status of the European XFEL Photon Beam System ion, FEL, MMI, undulator 144
 
  • F. Le Pimpec
    XFEL. EU, Hamburg, Germany
 
  The European XFEL located in the Hamburg region in Germany has finished its construction phase and is currently being commissioned. The European XFEL facility aims at producing X-rays in the range from 260~eV up to 24~keV out of three undulators that can be operated simultaneously with up to 27000~pulses/second. The FEL is driven by a 17.5~GeV linear accelerator based on TESLA-type superconducting accelerator modules. The accelerator has finished its first commissioning phase and is currently delivering photon beam to the experimental areas for commissioning in view to the user operation. This paper presents the status of the photon beam system from the undulators to the 3 experimental areas as well as the status of each instruments.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP044  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOP053 High Spectral Density Compton Back-Scattered Gamma-Ray Sources at Fermilab ion, electron, laser, radiation 174
 
  • D. Mihalcea, A. Khizhanok, P. Piot
    Northern Illinois University, DeKalb, Illinois, USA
  • B.T. Jacobson, A.Y. Murokh
    RadiaBeam, Santa Monica, California, USA
  • P. Piot, J. Ruan
    Fermilab, Batavia, Illinois, USA
 
  A ~1 MeV gamma-ray source is planned to be built at Fermilab following the completion of the ~300 MeV superconducting linac. The high-energy photons are back-scattered from the interactions between electrons and high-intensity IR laser pulses. In this contribution, we discuss some of the experiment design challenges and evaluate the performances of the gamma-ray source. We expect the peak brilliance to be of the order of 1022 photons/s-(mm-mrad)2-0.1\% BW and the spectral density of the radiation in excess of 3x105 photons/s/eV.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP053  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
MOP062 X-ray FEL Oscillator Seeded Harmonic Amplifier for High Energy Photons ion, FEL, electron, undulator 196
 
  • W. Qin, J. Wu
    SLAC, Menlo Park, California, USA
  • K.-J. Kim, R.R. Lindberg
    ANL, Argonne, Illinois, USA
 
  High-power, high-energy X-ray pulses in the range of several tens of keV have important applications for material sciences.* The unique feature of an X-ray FEL Oscillator (XFELO) makes it possible to seed a harmonic amplifier to produce such high energy photons.** In this contribution, we present simulation studies using 14.4-keV output pulses from an XFELO to generate harmonics around 40 keV (3rd harmonic) and 60 keV (4th harmonic). Techniques such as undulator tapering and fresh bunch lasing are considered to improve the amplifier performance.
* MaRIE project: http://www.lanl.gov/science-innovation/science-facilities/marie/.
** K.-J. Kim, XFELO-Seeded Amplifier, talk on MaRIE workshop, 2016.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-MOP062  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUB01 Seeding Experiments and Seeding Options for LCLS II ion, FEL, electron, laser 219
 
  • E. Hemsing, R.N. Coffee, W.M. Fawley, Y. Feng, B.W. Garcia, J.B. Hastings, Z. Huang, G. Marcus, D.F. Ratner, T.O. Raubenheimer
    SLAC, Menlo Park, California, USA
  • G. Penn, R.W. Schoenlein
    LBNL, Berkeley, California, USA
 
  We discuss the present status of FEL seeding experiments toward the soft x-ray regime and on-going studies on possible seeding options for the high repetition soft x-ray line at LCLS-II. The seeding schemes include self-seeding, cascaded HGHG, and EEHG to reach the 1-2 nm regime with the highest possible brightness and minimal spectral pedestal. We describe relevant figures of merit, performance expectations, and potential issues.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUB01  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUC02 Thermal and Mechanical Stability of Bragg Reflectors under Pulsed XFEL Radiation ion, radiation, FEL, laser 240
 
  • I. Bahns, C.P. Maag, J. Roßbach, P. Thiessen
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  • H. Sinn, V. Sleziona
    XFEL. EU, Hamburg, Germany
  • J. Zemella
    DESY, Hamburg, Germany
 
  Funding: BMBF FKZ 05K16GU4
Free-electron laser(FEL) x-ray radiation can deliver pulses with a huge amount of energy in short time duration. X-ray optics like Bragg reflectors therefore must be chosen in a way that they can withstand radiation-material interaction without getting damaged so that they can maintain their technical functionality. Therefore thermal and mechanical reactions of Bragg reflectors to the radiation induced thermal strain and force (radiation pressure) have been considered in this study. The theory of thermoelasticity has been used to simulate the strain conditions at saturation of the amplifying process in an X-ray free-electron laser oscillator(XFELO). One aim of this study was to investigate, if the radiation pressure could be an effect that gives a considerable contribution to the strain propagation. The results of the simulations have shown that, if Bragg backscattering of the X-ray pulse by a diamond crystal with 99% reflectivity and 1% absorptivity is assumed, the value of the thermally induced strain is about two magnitudes higher than the radiation pressure induced strain.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUC02  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUC05 Start-to-End Simulations for an X-Ray FEL Oscillator at the LCLS-II and LCLS-II-HE ion, FEL, electron, gun 247
 
  • W. Qin, K.L.F. Bane, Y. Ding, Z. Huang, G. Marcus, T.J. Maxwell
    SLAC, Menlo Park, California, USA
  • S. Huang, K.X. Liu
    PKU, Beijing, People's Republic of China
  • K.-J. Kim, R.R. Lindberg
    ANL, Argonne, Illinois, USA
 
  The proposed high repetition-rate electron beam from the LCLS-II and LCLS-II High Energy (LCLS-II-HE) upgrade are promising sources as drivers for an X-ray FEL Oscillator (XFELO) operating at both the harmonic and fundamental frequencies. In this contribution we present start-to-end simulations for an XFELO operating at the fifth harmonic with 4 GeV LCLS-II beam and at the fundamental with 8 GeV LCLS-II-HE beam. The electron beam longitudinal phase space is optimized by shaping the photoinjector laser and adjusting various machine parameters. The XFELO simulations show that high-flux output radiation pulses with 1010 photons and 3 meV (FWHM) spectral bandwidth can be obtained with the 8 GeV configuration.  
slides icon Slides TUC05 [3.802 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUC05  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUP023 Recent Developments and Plans for Two Bunch Operation with up to 1 μs Separation at LCLS ion, wakefield, experiment, gun 288
 
  • F.-J. Decker, K.L.F. Bane, W.S. Colocho, A.A. Lutman, J.C. Sheppard
    SLAC, Menlo Park, California, USA
 
  Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
To get two electron bunches with a separation of up to 1 microsecond at the Linac Coherent Light Source (LCLS) is important for LCLS-II developments. Two lasing bunches up to 220 ns have been demonstrated. Many issues have to be solved to get that separation increased by a factor of 5. The typical design and setup for one single bunch has to be questioned for many devices: RF pulse widths have to be widened, BPMs diagnostic can see only one bunch or a vector average, feedbacks have to be doubled up, the main Linac RF needs to run probably un-SLEDed, and special considerations have to be done for the Gun and L1X RF.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUP023  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUP066 Luminosity Increase in Laser-Compton Scattering by Crab Crossing ion, laser, luminosity, electron 368
 
  • Y. Koshiba
    Waseda University, Tokyo, Japan
  • T. Higashiguchi
    Center for Optical Research and Education, Utsunomiya University, Utsunomiya, Japan
  • S. Ota, T. Takahashi, M. Washio
    RISE, Tokyo, Japan
  • K. Sakaue
    Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan
  • J. Urakawa
    KEK, Ibaraki, Japan
 
  Funding: Research Fellow of Japan Society for the Promotion of Science
Laser-Compton Scattering X-ray (LCS-X) sources have been expected as compact and powerful sources, beyond X-ray tubes. They will enable laboratories and companies, opening new X-ray science. It is well known that luminosity depends on the collision angle of a laser and electron beam. Head-on collision is ideal in the point of maximizing the luminosity, though it is difficult to create such a system especially with an optical enhancement cavity for a laser. In collider experiments, however, crab crossing is a promising way to increase the luminosity. We are planning to apply crab crossing to LCS to achieve a higher luminosity leading to a more intense X-ray source. Electron beams will be tilted to half of the collision angle using an RF-deflector. Although crab crossing in Laser-Compton scattering has been already proposed, it has not been demonstrated yet anywhere.* The goal of this study is to experimentally prove the luminosity increase by adopting crab crossing. In this conference, we will report about our compact accelerator system at Waseda University, laser system favorable for crab crossing LCS, and expected results of crab crossing LCS.
* V. Alessandro, et al., "Luminosity optimization schemes in Compton experiments based on Fabry-Perot optical resonators." Physical Review Special Topics-Accelerators and Beams 14.3 (2011): 031001.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-TUP066  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEP063 A Two-in-One Type Undulator undulator, ion, FEL, electron 547
 
  • D. Wang, H.X. Deng, Z. Jiang
    SINAP, Shanghai, People's Republic of China
 
  Funding: This work is supported by the Ministry of Science and Technology of China.
The typical X-ray free electron lasers have long tunnels to accommodate high energy electron linear accelerator and long undulator line to produce intense coherent radiations at very short wavelengths. The number of undulator lines is limited by the available space in the tunnel. This is especially true for those facilities that adopt underground tunnels or utilize the existing tunnels originally built for other purpose. This work explored the possibility to better use the tunnel space for accommodating more FEL undulator lines by designing a new type of undulator structure.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2017-WEP063  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)