MC2: Photon Sources and Electron Accelerators
A06 Free Electron Lasers
Paper Title Page
TUYPLM1 XFEL Performance Achieved at PAL-XFEL 1182
 
  • H. Heo, M.-H. Cho, J.H. Han, H.-S. Kang, C. Kim, G. Kim, M.J. Kim, J.H. Ko, H.-S. Lee, C.-K. Min, I.H. Nam, K.-H. Park, C.H. Shim, H. Yang
    PAL, Pohang, Kyungbuk, Republic of Korea
 
  The hard X-ray free electron laser at Pohang Accelerator Laboratory (PAL-XFEL) successfully completed the commissioning of SASE and started user operation in late 2016. Since then, the facility has demonstrated excellent stability with very small timing jitter of about 20 fs, and commissioned the self-seeding system over a wide range of photon energies, etc. The talk will provide an overview of the last three years at the PAL-XFEL, including some detailed experimental results, as well as future prospects for the laboratory.  
slides icon Slides TUYPLM1 [7.516 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUYPLM1  
About • paper received ※ 20 May 2019       paper accepted ※ 24 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUYPLM2
Stable and Brilliant Self-Seeded XFEL at SACLA  
 
  • I. Inoue
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
 
  A new self-seeding experiment on the hard x-ray free-electron laser (XFEL) is in progress at the XFEL facility, SACLA. Self-seeding of a hard x-ray FEL has been demonstrated at SLAC and SACLA using a transmission type scheme with a single crystal. However, the gain of the spectral brightness is limited in the transmission type scheme. Therefore, a reflection type self-seeding system with a pair of channel-cut crystals has been developed at SACLA and self-seeding experiments have been performed. Adoption of a channel-cut crystal is critically important to minimize the delay of the seed laser from the electron bunch. Preliminary results showed much higher spectral brightness and much better stability than the transmission scheme. This talk presents the design of the reflection type scheme and the performance of the self- seeded XFEL obtained at SACLA.  
slides icon Slides TUYPLM2 [72.122 MB]  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMP048 Current Status of Turkish Accelerator and Radiation Laboratory 1359
 
  • A.A. Aksoy, Ö.F. Elçim
    Ankara University Institute of Accelerator Technologies, Golbasi, Turkey
  • Ö. Karslı, Ç. Kaya, B. Koc
    Ankara University, Accelerator Technologies Institute, Golbasi, Turkey
 
  Funding: T.R. Presidency Strategy and Budget Office Grand No: 2006K-120470
Turkish Accelerator and Radiation Laboratory (TARLA) which is designed to deliver various accelerator based radiation sources, aims to be outstanding research instrument for users from both Turkey and region. Within the current scope of TARLA its superconducting accelerator will drive two of free electron laser (FEL) beamlines in order to provide Continuous Wave (CW) tunable radiation of high brightness in the mid- and far-infrared range as well as a Bremmstrahlung radiation station. Main components of TARLA, such as injector, superconducting accelerating modules and cryoplant are under commissioning currently. In this paper commissioning results and current status of facility are presented.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPMP048  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB008 LUXE - a QED Experiment at the European XFEL 1694
 
  • F. Burkart, R.W. Aßmann, R. Brinkmann, W. Decking, N. Golubeva, B. Heinemann, M. Hüning, J. List, M. Wing
    DESY, Hamburg, Germany
  • M. Wing
    UCL, London, United Kingdom
 
  The proposed experiment aims to measure QED in the presence of strong fields and above the Schwinger critical field. An experiment is being considered at the European XFEL, which should be able to measure non-perturbative QED and its transition from the perturbative regime. This paper presents the current status of the LUXE (Laser und XFEL Experiment) design study. First layout considerations; accelerator beam line design, electron and laser beam parameters, radioprotection issues and first results of the start to end simulations will be presented and discussed in detail. An outlook concerning the implementation into the XFEL schedule and timeline of this experiment will be given.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB008  
About • paper received ※ 14 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB010 FIRST DESIGN STUDIES OF A NC CW RF GUN FOR EUROPEAN XFEL 1698
 
  • S. Shu, Y. Chen, S. Lal, H.J. Qian, H. Shaker, F. Stephan
    DESY Zeuthen, Zeuthen, Germany
 
  After the successful commissioning of the European XFEL in pulsed mode, continuous wave (CW) mode operation of European X-ray Free-Electron Laser (XFEL) is under considerations for future upgrade. DESY is push-ing R&D on CW electron sources. A fully superconducting CW gun is under experimental development at DESY in Hamburg, and a normal conducting (NC) CW gun is under physics design at the Photo Injector Test facility at DESY in Zeuthen (PITZ) as a backup option. A 217 MHz NC CW gun is developed from the LBNL 187 MHz VHF gun, with enhancement on both cathode gradient and gun voltage to further improve beam brightness. This paper presents the cavity RF design, multipacting (MP) simula-tions and beam dynamics studies.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB010  
About • paper received ※ 17 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB012 Design of High Power CW IR-THz Source for the Radiation Source ELBE Upgrade 1702
 
  • P.E. Evtushenko, T.E. Cowan, U. Lehnert, P. Michel
    HZDR, Dresden, Germany
 
  The Radiation Source ELBE at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) is a user facility based on a 1 mA - 40 MeV CW SRF LINAC. Presently HZDR is considering upgrade options for the ELBE or its replacement with a new CW, SRF LINAC-based user facility. A part of the user requirements is the capability to generate IR and THz pulse in the frequency range from 0.1 through 30 THz, with pulse energies in the range from 100 uJ through a few mJ, at the repetition rate between 100 kHz and 1 MHz. This corresponds to the pulse energy increase, dependent on the wavelength by a factor from 100 through 1000. In this contribution, we outline key aspects of a concept, which would allow to achieve such parameters. Such key aspects are: 1 - use of a beam with longitudinal density modulation and bunching factor of about 0.5 at the fundamental frequency; 2 - achieving the density modulation through the mechanism similar to the one used in optical klystron (OK) and HGHG FEL; 3 - generating necessary for the modulation optical beam by an FEL oscillator, and 4 - using two electron injectors, where one injector provides beam for the FEL oscillator while second high charge injector provides beam for the high energy per pulse generation for user experiments. All-in-all the concept of the new radiation source is very similar to an OK, but operating with two beams simultaneously.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB012  
About • paper received ※ 21 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB013 Simulation Studies for a EEHG seeded FEL in the XUV 1705
SUSPFO014   use link to see paper's listing under its alternate paper code  
 
  • V. Grattoni, S. Ackermann, R.W. Aßmann, B. Faatz, T. Lang, C. Lechner, M.M. Mohammad Kazemi, G. Paraskaki, J. Zemella
    DESY, Hamburg, Germany
  • W. Hillert
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  • S. Reiche
    PSI, Villigen PSI, Switzerland
 
  Echo-enabled harmonic generation (EEHG) is a promising technique for seeded free electron lasers (FELs) not only to go down to wavelengths of 4 nm, but also to simplify the schemes that are currently used to achieve a similar wavelength range (double cascade HGHG). Thus a study optimizing the EEHG performance in the wavelength range from 60 to §I{4}{nm} has been performed. The more critical working point, at 4 nm, is here analyzed in terms of seed laser energy stability for two different seed laser frequencies: visible and UV.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB013  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB018 Design Studies of a Proof-of-Principle Experiment on THz SASE FEL at PITZ 1713
 
  • X. Li, P. Boonpornprasert, Y. Chen, J.D. Good, M. Groß, H. Huck, I.I. Isaev, C. Koschitzki, M. Krasilnikov, S. Lal, O. Lishilin, G. Loisch, D. Melkumyan, R. Niemczyk, A. Oppelt, H.J. Qian, H. Shaker, S. Shu, F. Stephan, G. Vashchenko
    DESY Zeuthen, Zeuthen, Germany
 
  A free-electron laser based THz source is undergoing design studies at the Photo Injector Test facility at DESY in Zeuthen (PITZ). It is considered as a prototype for pump-probe experiments at the European XFEL, benefiting from the fact that the electron beam from the PITZ facility has an identical pulse train structure as the XFEL pulses. In the proposed proof-of-principle experiment, the electron beam (up to 4 nC bunch charge and 200 A peak current) will be accelerated to 16-22 MeV/c to generate SASE radiations in an LCLS-I undulator in the THz range between 60 and 100 µm with an expected energy of up to ~1 mJ/pulse. In this paper, we report our simulations on the optimization of the photo-injector and the design of the transport and matching beamline. Experimental investigations on the generation, characterization and matching of the high charge beam in the existing 22-m-long beamline will also be presented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB018  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB019 Collimator Performance Study at the European XFEL 1717
 
  • S. Liu, F. Brinker, W. Decking, L. Fröhlich, N. Golubeva, T. Wamsat, J. Wilgen
    DESY, Hamburg, Germany
 
  Beam halo collimation is of great importance for the high repetition rate operation at the European XFEL and for the future CW machines. At the European XFEL several different types of collimators are installed at different locations of the beam line, which include the gun collimators, the bunch compressor collimators, and the main and supplementary collimators in the collimation section. Beam halo measurements have been performed using the wire scanners downstream of the main linac, which show that large part of beam halo is collimated by the gun collimator. Remaining losses in the collimation section are mainly due to misalignment. Alignment using orbit bumps in the collimation section is performed and presented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB019  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB020 Status of the European XFEL 1721
 
  • W. Decking, F. Brinker, L. Fröhlich, R. Kammering, T. Limberg, S. Liu, D. Nölle, M. Omet, M. Scholz, T. Wamsat
    DESY, Hamburg, Germany
 
  The European XFEL is a Hard X-ray Free Electron Laser based on superconducting accelerator technology. In operation since 2017, it now serves 3 FEL beamlines simultaneously for user experiments. We will report on the present operation of the linear accelerator, the beam distribution to the various beamlines and the performance of the FEL radiators.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB020  
About • paper received ※ 15 May 2019       paper accepted ※ 17 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB024 A Concept for Upgrade of FLASH2 Undulator Line 1736
 
  • E. Schneidmiller, B. Faatz, I. Hartl, S. Schreiber, M. Tischer, M. Vogt, M.V. Yurkov, J. Zemella
    DESY, Hamburg, Germany
  • W. Wurth
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
 
  FLASH is the first soft X-ray FEL user facility, routinely providing brilliant photon beams for users since 2005. There are plans to upgrade both existing undulator lines of this facility, FLASH1 and FLASH2. FLASH1 will mainly operate in XUV range in seeding and SASE modes, while FLASH2 will use the standard SASE regime as well as new lasing concepts aiming at production of brilliant photon beams on the fundamental and harmonics down to 1nm. In this paper we present a concept for FLASH2 upgrade, and discuss different advanced options.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB024  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB025 Harmonic Lasing of the European XFEL in the Angstrom Regime 1740
 
  • E. Schneidmiller, F. Brinker, W. Decking, D. Nölle, M.V. Yurkov, I. Zagorodnov
    DESY, Hamburg, Germany
  • N. Gerasimova, J. Grünert, N.G. Kujala, J. Laksman, Y. Li, J. Liu, Th. Maltezopoulos, I. Petrov, L. Samoylova, S. Serkez, H. Sinn, F. Wolff-Fabris
    EuXFEL, Hamburg, Germany
 
  Harmonic lasing in XFELs is an opportunity to extend the photon energy range of existing and planned X-ray FEL user facilities. Contrary to nonlinear harmonic generation, harmonic lasing can provide much more intense, stable, and narrow-band FEL beam. Another interesting application is Harmonic Lasing Self-Seeding (HLSS) that allows to improve longitudinal coherence and spectral power of a Self-Amplified Spontaneous Emission (SASE) FEL. This concept was successfully tested at FLASH2 in the range of 4.5 - 15 nm and at PAL XFEL at 1 nm. In this contribution we present recent results from the European XFEL where we successfully demonstrated operation of HLSS FEL at 5.9 A, thus pushing harmonic lasing for the first time into the Angstrom regime.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB025  
About • paper received ※ 09 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB026 Optics & Compression Schemes for a Possible FLASH Upgrade 1744
 
  • J. Zemella, M. Vogt
    DESY, Hamburg, Germany
 
  The proposed FLASH upgrade will rely on high quality electron beams provided to all undulator beamlines. Here we describe possible modifications to the FLASH lattice and the compression scheme that aim at improving the beam quality and the ability to control critical beam properties along the machine - simultaneously and independently for all beamlines.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB026  
About • paper received ※ 11 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB027 Upgrade Plans for FLASH for the Years After 2020 1748
 
  • M. Vogt, K. Honkavaara, J. Rönsch-Schulenburg, S. Schreiber, J. Zemella
    DESY, Hamburg, Germany
 
  FLASH is a unique superconducting soft X-ray FEL capable of producing up to 8000 photon pulses per second. A substantial upgrade is planned to keep FLASH attractive and competitive. Several upgrade scenarios are discussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB027  
About • paper received ※ 14 May 2019       paper accepted ※ 19 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB031 FERMI Configuration for the Echo Enabled Harmonic Generation Experiment 1752
 
  • E. Allaria, D. Castronovo, M. Cautero, I. Cudin, M.B. Danailov, B. Diviacco, L. Giannessi, M. Veronese, M. Zangrando
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
 
  The FERMI FEL-2 undulator line, normally operated in the double stage high gain harmonic generation with the fresh bunch (HGHG-FB) has been temporary modified to allow operating the FEL in the Echo Enabled Harmonic Generation (EEHG) scheme. An increase of the dispersion in the delay-line was required together with a replacement of the second stage modulator allowing the electron beam to resonantly interact with a second seed laser. Another critical component of the EEHG setup is a new manipulator installed in the delay-line chicane and hosting additional diagnostic components. In this work we describe in some detail these new components that allowed a successful demonstration of the EEHG at harmonics as high as 101.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB031  
About • paper received ※ 17 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB032 The CompactLight Design Study Project 1756
 
  • G. D’Auria, S. Di Mitri, R.A. Rochow
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • M. Aicheler
    HIP, University of Helsinki, Finland
  • A.A. Aksoy
    Ankara University, Accelerator Technologies Institute, Golbasi, Turkey
  • D. Alesini, M. Bellaveglia, B. Buonomo, F. Cardelli, M. Croia, M. Diomede, M. Ferrario, A. Gallo, A. Giribono, L. Piersanti, B. Spataro, C. Vaccarezza
    INFN/LNF, Frascati, Italy
  • R. Apsimon, A. Castilla
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • J.M. Arnesano, F. Bosco, L. Ficcadenti, A. Mostacci, L. Palumbo
    Sapienza University of Rome, Rome, Italy
  • A. Bernhard, J. Gethmann
    KIT, Karlsruhe, Germany
  • G. Burt
    Lancaster University, Lancaster, United Kingdom
  • M. Calvi, T. Schmidt, K. Zhang
    PSI, Villigen PSI, Switzerland
  • H.M. Castaneda Cortes, J.A. Clarke, D.J. Dunning, N. Thompson
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A.W. Cross, L. Zhang
    USTRAT/SUPA, Glasgow, United Kingdom
  • G. Dattoli, F. Nguyen, A. Petralia
    ENEA C.R. Frascati, Frascati (Roma), Italy
  • R.T. Dowd, D. Zhu
    AS - ANSTO, Clayton, Australia
  • W.D. Fang
    SINAP, Shanghai, People’s Republic of China
  • A. Faus-Golfe, Y. Han
    LAL, Orsay, France
  • E.N. Gazis, N. Gazis
    National Technical University of Athens, Athens, Greece
  • R. Geometrante, M. Kokole
    KYMA, Trieste, Italy
  • V.A. Goryashko, M. Jacewicz, R.J.M.Y. Ruber
    Uppsala University, Uppsala, Sweden
  • X.J.A. Janssen, J.M.A. Priem
    VDL ETG, Eindhoven, The Netherlands
  • A. Latina, X. Liu, C. Rossi, D. Schulte, S. Stapnes, X.W. Wu, W. Wuensch
    CERN, Geneva, Switzerland
  • O.J. Luiten, P.H.A. Mutsaers, X.F.D. Stragier
    TUE, Eindhoven, The Netherlands
  • J. Marcos, E. Marín, R. Muñoz Horta, F. Pérez
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  • G. Taylor
    The University of Melbourne, Melbourne, Victoria, Australia
 
  Funding: This project has received funding from the European Union’s Horizon2020 research and innovation programme under grant agreement No 777431
The H2020 CompactLight Project (www. CompactLight.eu) aims at designing the next generation of compact X-rays Free-Electron Lasers, relying on very high gradient accelerating structures (X-band, 12 GHz), the most advanced concepts for bright electron photo injectors, and innovative compact short-period undulators. Compared to existing facilities, the proposed facility will benefit from a lower electron beam energy, due to the enhanced undulators performance, and will be significantly more compact, with a smaller footprint,  as a consequence of the lower energy and the high-gradient X-band structures. In addition, the whole infrastructure will also have a lower electrical power demand as well as lower construction and running costs.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB032  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB035 Stimulated Emission of THz Coherent Diffraction Radiation in an Optical Cavity by a Multibunch Electron Beam 1763
 
  • Y. Honda, A. Aryshev, R. Kato, T. Miyajima, T. Obina, M. Shimada, R. Takai, T. Uchiyama, N. Yamamoto
    KEK, Ibaraki, Japan
 
  Funding: JSPS KAKENHI
Accelerator-based terahertz (THz) radiation has been expected to realize a high-power broad-band source. Employing a low-emittance and short-bunch electron beam at a high repetition rate, a scheme to resonantly excite optical cavity modes of THz spectrum range via coherent diffraction radiation has been proposed. The confocal cavity design is the special case that resonance conditions of all the eigen modes coincide, resulting in realizing broad-band excitation. But in general cases of non-confocal cavities, the resonance condition depends on the mode, and the resonance peak becomes wide and weak. We performed an experiment with a non-confocal cavity as a follow-up experiment of that we have done with a confocal cavity. The result confirmed that the confocal design is the key for a broad-band source.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB035  
About • paper received ※ 26 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB039 Research of Coherent Edge Radiation Generated by Electron Beams Oscillating Free-Electron Lasers 1772
 
  • N. Sei, H. Ogawa
    AIST, Tsukuba, Ibaraki, Japan
  • K. Hayakawa, Y. Hayakawa, K. Nogami, T. Sakai, Y. Sumitomo, Y. Takahashi, T. Tanaka
    LEBRA, Funabashi, Japan
  • H. Ohgaki, H. Zen
    Kyoto University, Kyoto, Japan
 
  Funding: JSPS KAKENHI Grant Number JP16H03912
We have studied far-infrared coherent radiation with an S-band linac at Laboratory for Electron Beam Research and Application (LEBRA) at Nihon University. We have already developed a couple of terahertz-wave sources based on coherent synchrotron radiation and coherent transition radiation*, which have been applied to spectroscopic research**. Moreover, we developed coherent edge radiation (CER) at the downstream bending magnets in the FEL sections. Because the edge radiation has an annular shape distribution characterized by the asymmetric first-order Laguerre-Gaussian mode, the CER can be extracted from an optical cavity of the FEL system without a diffraction loss of the FEL beam***. The root-mean-squared bunch length of the electron beam was evaulated by measuring the CER spectra, which was about the same level as the FEL micropulse width. Although the infrared FELs at LEBRA had a long slippage length, the CER intensity can be a guidepost enhancing the FEL power because of the existence of their correlation. In this presentation, the characteristics of the CER including correlation between the CER and the FEL will be reported.
* N. Sei et al., Jpn. J. Appl. Phys. 56, (2017) 032401.
** N. Sei et al., J. Opt. Soc. Am. B, 31, (2014) 2150.
*** N. Sei et al., Phys. Lett. A in press.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB039  
About • paper received ※ 19 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB040 Development of Coherent Terahertz Wave Sources and Transport Systems at LEBRA Linac 1775
 
  • T. Sakai, K. Hayakawa, Y. Hayakawa, K. Nogami, Y. Sumitomo, T. Tanaka
    LEBRA, Funabashi, Japan
  • H. Ogawa, N. Sei
    AIST, Tsukuba, Ibaraki, Japan
 
  Funding: This work was supported by JSPS KAKENHI (Grant-in-Aid for Young Scientists (B)) Grant Number JP16K17539 and JP16H03912.
Development of a 125 MeV S-band electron linac for the generation of Free Electron Laser (FEL), Parametric X-ray Radiation (PXR) and coherent terahertz waves (THz waves) has been underway at LEBRA of Nihon University as a joint research with KEK and National Institute of Advanced Industrial Science and Technology (AIST). The high power coherent transition radiation (CTR), coherent edge radiation (CER) and the coherent synchrotron radiation (CSR) wave sources development has been carried out since 2011 at LEBRA. The transport systems of the each THz wave were installed in the vacuum chamber on the downstream side of the 45 degrees bending magnet of the PXR and FEL beam-line. In particular, a CER of the generated the FEL beam line can also be guided without disturbing the FEL oscillations. Additionally, a part of the mirror of the transport optical system is constructed using Indium Tin Oxide (ITO) mirror with the optimized for the transport of the THz wave. In this report, construction of the THz transport beam lines and the property of the THz lights are discussed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB040  
About • paper received ※ 19 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB041 Simulation of Short-Pulse Generation from a Dynamically Detuned IR-FEL Oscillator and Pulse Stacking at an External Cavity 1778
 
  • Y. Sumitomo, Y. Hayakawa, T. Sakai
    LEBRA, Funabashi, Japan
  • R. Hajima
    QST, Tokai, Japan
 
  Funding: Q-LEAP program supported by Ministry of Education, Culture, Sports, Science and Technology, Japan
At the LEBRA facility of Nihon U., we have an IR-FEL oscillator to generate radiations in the range of wavelengths 1-6 um for various experiments. A research program has been established to explore the application of the IR-FEL to generate attosecond UV and X-ray pulses through the high harmonic generation (HHG) in noble gases, where the IR-FEL pulses must have a high-peak power and a short-pulse duration. The property of generated FEL pulse is affected by the cavity length detuning of FEL oscillator as well as the small signal gain and the cavity loss. The operation at a small- or zero-detuning length is necessary to generate a FEL pulse shorter than the bunch length, although it requires a long macro-pulse to reach the saturation. For the short FEL pulse generation within a limited macro-pulse length at the LEBRA LINAC, we apply a dynamical modulation to the electron bunch repetition, that is equivalent to a dynamical detuning of the FEL cavity length. We illustrate the potential performance of the IR-FEL with the dynamical detuning by time-dependent 3D FEL simulations. We also evaluate the enhancement of the FEL pulses by an external cavity stacking for the sake of the HHG application.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB041  
About • paper received ※ 29 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB042 Design Study of Nonlinear Energy Chirp Correction Using Sextupole Magnets at the Soft X-Ray Free-Electron Laser Beamline of SACLA 1782
 
  • K. Togawa, T. Hara, H. Tanaka
    RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
 
  At the x-ray free-electron laser (FEL) facility, SACLA, a soft x-ray FEL beamline (SCSS+) is driven by a dedicated 800-MeV electron accelerator and being operated in parallel with two hard x-ray FEL beamlines. Responding to the demands of short laser pulses from users, a nonlinearity correction system using sextupole magnets is under consideration to obtain shorter electron bunches. Since the frequency of the SCSS+ injector is S-band, the nonlinearity correction of a bunch compression process using a harmonic correction cavity is not so efficient as the SACLA injector, whose frequency of the injector is L-band. Instead of a complex and costly correction cavity system, the sextupole magnets are simply installed in a dispersive section of the first bunch compressor chicane. In this report, we will present the basic design concept and some detail studies of the nonlinear correction.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB042  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB045 Stimulated Excitation by Seeding With Cherenkov Radiation in an Optical Cavity 1785
SUSPFO058   use link to see paper's listing under its alternate paper code  
 
  • S.M. Jiang, Z.G. He, Q.K. Jia, W.W. Li, L. Wang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
  • D. He
    Anhui Electrical Engineering Professional Technique College, Hefei, People’s Republic of China
 
  Funding: Work supported by National Foundation of Natural Sciences of China (11775216, 11705198, 11675178), and Fundamental Research Funds for the Central Universities (WK2310000061).
By seeding with narrow-band Cherenkov radiation from a dielectric loaded waveguide(DLW), stimulated excitation in an optical cavity is presented. The evolution and energy loss of the field oscillating in optical cavity is analysed by the theoretical and numerical calculation. The results show that the high order TM modes of the Cherenkov radiation can be better preserved after a large number of roundtrips in the optical cavity and this scheme offers a potential method of realizing high power Terahertz radiation source in a compact facility.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB045  
About • paper received ※ 30 April 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB046 Second Order Intensity Correlation and Statistical Properties of a Soft X-Ray Free Electron Laser 1788
 
  • C.L. Li, J.H. Chen, Z.C. Chen, X.T. Wang, H.L. Wu
    SINAP, Shanghai, People’s Republic of China
  • B. Liu, T. Liu
    SARI-CAS, Pudong, Shanghai, People’s Republic of China
 
  High degree of transverse field coherence is one of the unique properties of an FEL compared with a 3rd gen-eration storage ring light source. As a result, the FEL advances the development of innovative research and technology that was not previously feasible. A truly coherent source should be coherent in all orders de-scribed from the intensity correlation functions. In this paper, second order intensity correlation of FEL radia-tion is investigated based on the Hanbury Brown-Twiss intensity correlation method. The statistical properties of radiation produced from SASE was also investigated and compared with the statistical proper-ties of a phase-locked laser. The results show that the statistical properties of a SASE mode behave as a cha-otic source, which is significantly different from the properties of a phase-locked laser beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB046  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB047 Proposal of the Reflection Hard X-Ray Self-Seeding at the SHINE Project 1792
 
  • T. Liu, C. Feng
    SARI-CAS, Pudong, Shanghai, People’s Republic of China
 
  FEL self-seeding has been demonstrated a great advantage for the generation of a fully coherent and high brightness X-ray pulse experimentally. Generally, transmission monochromators with single crystal are adopted worldwide, such as LCLS, PAL-XFEL and European-XFEL. Recently, the self-seeding scheme based on a reflection monochromator with a double-crystal is proposed and demonstrated at SACLA successfully. In view of several potential advantages of the reflection type, here we give the proposal of the reflection monochromator based self-seeding and enable the application on the SHINE project. This manuscript is mainly focus on monochromator schemes at SHINE, instead of FEL simulations. We will present considerable schemes based on the specific undulator line.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB047  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB050 The Optical Resonator of CTFEL for Range of 1 to 2 THz 1795
 
  • X.J. Shu, Y.H. Dou
    Institute of Applied Physics and Computational Mathematics, People’s Republic of China
 
  A high power THz free electron laser (FEL) facility is under construction at China Academy of Engineering Physics (CTFEL). The radiation frequency of the FEL facility will be tuned in range of 1~3 THz and the average output power is about 10 W. The system mainly consists of a GaAs photoemission DC gun, superconductor accelerator, hybrid wiggler, optical cavity. The first lasing is obtained on Aug. 29, 2017, and CTFEL is operated in range of 2-4THz, but cannot lasing at the frequency below 1.8 THz. The optical resonator of CTFEL must be optimized to ensure lasing in range of 1 to 2 THz.. The lasing strongly depends on the performance of the optical resonator including output efficiency, gain and round-trip loss. The optical resonator consists of metal-coated reflect mirror, the centre-hole output mirror, waveguide. The influence of waveguide on the quality of optical cavity is evaluated by the 3D OSIFEL code. The waveguide size and output hole radius is optimized to different frequencies between 1 THz to 2 THz.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB050  
About • paper received ※ 13 May 2019       paper accepted ※ 24 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB053 Injector Physics Design at SHINE 1801
 
  • Z. Wang, M.H. Zhao
    SINAP, Shanghai, People’s Republic of China
  • Q. Gu
    SSRF, Shanghai, People’s Republic of China
  • G.L. Wang
    DICP, Dalian, People’s Republic of China
 
  As a CW x-ray free electron laser facility, SHINE has a high requirement on the electron beam quality in the linac, as well as in the injector. SHINE injector consists of a 162.5 MHz normal conducting VHF gun, a NC 1.3 GHz RF buncher, a one cavity SC cryomodule, an eight cavity SC cryomodule and 3 solenoids along the injector layout. Some beam diagnostic element are inserted in the layout as well. In this paper, we try to introduce the injector physics design at shine.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB053  
About • paper received ※ 15 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB054 The Beam-Based Alignment Simulation and Preliminary Experiment at SXFEL 1804
 
  • L. Zeng, H.X. Deng, C. Feng, D. Gu, B. Liu, Z.T. Zhao
    SINAP, Shanghai, People’s Republic of China
  • G.L. Wang
    DICP, Dalian, People’s Republic of China
 
  The Shanghai soft X-ray Free-electron Laser facility (SXFEL) is now serving as an experimental platform for fundamental free-electron laser (FEL) principle tests. The machine puts very tight tolerance on the straightness of the electron beam orbit. It is hard to achieve the required trajectory due to the off-axis field of the misaligned quadrupoles and undulator segments especially for the SXFEL driven by low energy linac (840MeV). This tight requirement on electron beam straightness can only be met through the beam-based alignment (BBA) technology which achieved great success at LCLS, PAL-XFEL, European-XFEL and SCALA with high electron beam energies. But there has been no report about satisfactory BBA experiment results on soft X-ray FEL facility driven by relatively low energy linacs (on the order of 2 GeV or less) up to now. Here, we report the simulation results and preparatory experiment progress of the BBA at SXFEL with the method of dispersion-free steering (DFS). The experiment results show some improvements of the electron beam orbit and the phenomenon of the dispersion-free. The entire BBA experiment and a feedback system of electron beam trajectory may also be included.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB054  
About • paper received ※ 18 April 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB057 THz-Pump and UV-Probe Scheme Based on Storage Ring 1811
SUSPFO083   use link to see paper's listing under its alternate paper code  
 
  • H.R. Zhang, Z.G. He, S.M. Jiang, W.X. Wang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  We propose a THz-pump and UV-probe scheme based on storage ring for ultra-fast dynamics experiment. In which, two sequential laser pulses, one of which has a periodic intensity envelope, simultaneously interact with different parts of the long electron beam in a modulator; after a chicane, the part that interacts with the periodic pulse will bunch at THz domain and radiate through a bend magnet, another based on high-harmonic generation will bunch at UV domain and radiate at a radiator. The electron beam can be utilized circularly in the storage ring, which will increase its average power. The feasibility of this THz-pump and UV-probe scheme is verified in both theory and simulation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB057  
About • paper received ※ 30 April 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB059 Solid State Amplifier of SC Linac for Shine 1814
 
  • Y.B. Zhao, Q. Chang, K. Xu, Zh.G. Zhang, S.J. Zhao, X. Zheng
    SINAP, Shanghai, People’s Republic of China
 
  Shanghai HIgh repetition rate XFEL aNd Extreme light facility (SHINE)is a platform for technique and science research which energy is 8GeV, operated in CW-mode and beam current is 0.2mA. It include a LINAC of 8GeV, three undulator lines, three beam lines and ten experiment stations. SHINE is located underground 30 meters. The lengths of facility is 3kM and the length of LINAC is 1.2km. The acceleration architecture of LINAC consists of six hundred 1.3GHz and sixteen 3.9GHz TELSA type cavities. The 5.2kW SSA will drive the 1.3GHz superconductive cavities and 2kW SSA will power the 3.9GHz superconductive cavities. Four 1.3GHz prototypes of SSA have already been produced, the design and performance are showed in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB059  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB061 Seeded Free-Electron Lasers Driven by a Transverse Tilted Electron Bunch 1817
 
  • Z. Zhao, Q.K. Jia, H.T. Li
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  Funding: Work supported by the China Postdoctoral Science Foundation (No. 2018M642542) and the Fundamental Research Funds for the Central Universities (WK2310000081).
A transverse tilt of the electron bunch is normally unwanted in free-electron laser (FEL) since only a portion of the bunch can contribute to the FEL radiation. However, the recent researches demonstrate that the tilted bunch can be used to generate FEL with some special features. In this work we investigate the generation of a large tilt of the bunch by using a corrugated structure and a dogleg separately. Based on the tilted bunch, the creation of ultra-short pulse and multi-color pulses are demonstrated in high-gain harmonic generation (HGHG) FEL.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB061  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB062 Coherence Time Characterization for Self-Amplified Spontaneous Emission Free-Electron Lasers 1820
 
  • G. Zhou, Y. Jiao, J.Q. Wang
    IHEP, Beijing, People’s Republic of China
  • T.O. Raubenheimer, J. Wu
    SLAC, Menlo Park, California, USA
  • C.-Y. Tsai
    HUST, Wuhan, People’s Republic of China
  • C. Yang
    USTC/NSRL, Hefei, Anhui, People’s Republic of China
 
  One of the key challenges in scientific researches based on free-electron lasers (FELs) is the characterization of the coherence time of the ultra-fast hard x-ray pulse, which fundamentally influences the interaction process between x-ray and materials. Conventional optical methods, based on autocorrelation, is very difficult to realize due to the lack of mirrors. Here, we experimentally demonstrate a conceptually new coherence time characterization method and a coherence time of 174.7 attoseonds has been measured for the 6.92 keV FEL pulses at Linac Coherent Light Source. In our experiment, a phase shifter is adopted to control the cross-correlation between x-ray and microbunched electrons. This approach provides critical temporal coherence diagnostics for x-ray FELs, and is decoupled from machine parameters, applicable for any photon energy, radiation brightness, repetition rate and FEL pulse duration, etc.
The work was supported by the US Department of Energy (DOE) under contract DE-AC02-76SF00515 and the US DOE Office of Science Early Career Research Program grant FWP-2013-SLAC-100164.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB062  
About • paper received ※ 01 May 2019       paper accepted ※ 28 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB069 Study of FEL Operation Using Collimator without X-band Linearizer in HX Line at PAL-XFEL 1824
 
  • H. Yang, C.-K. Min, I.H. Nam
    PAL, Pohang, Kyungbuk, Republic of Korea
 
  Funding: This work is supported by MSIP, Korea.
A Hard X-ray (HX) line in PAL-XFEL consists of an e-gun, a Laser Heater (LH), S-band accelerators, an X-band LINearizer (XLIN), three Bunch Compressors (BC), a dog-leg, and an undulator line. It generates 2.5 - 15-keV FEL with over than 1-mJ pulse energy. The XLIN before BC1 is used for linearizing the energy chirp in the longitudinal phase space and provides the flexibility for FEL optimization and operation. However, it causes the instability of FEL by large jitters and drift because of higher frequency. We study the FEL operation without XLIN. The collimator in the center of BC1 is used removing the slices to cause nonlinear compression. We optimize the FEL by short electron bunch with under 30 fs. In this paper, we present details of the optimizing sequence and performance for the FEL operation without XLIN.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB069  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB070 A Peak Finding Algorithm for FEL Spectra Characterization 1827
 
  • M.A. Pop
    MAX IV Laboratory, Lund University, Lund, Sweden
  • E. Allaria
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
 
  We present a software tool aimed at investigating the spectra of photon sources in order to detect any instabilities in the electron beam that have a clear effect on the spectrum. The method has been developed for FERMI@Elettra but with a general approach on the particularities of FEL machines such as a high repetition frequency and significant shot to shot fluctuations. The software has two operating options: a mode, aimed at online usage, which only detects peaks and their corresponding valleys, offering no information about the peaks themselves; and a more comprehensive mode that fits peak functions (Gaussian, Lorentzian etc…) to the spectrum based on initial guesses of the fitting parameters. The algorithm can provide a collection of simple but valuable variables such as number of peaks, peak separation and ratio between peak heights, as well as more specialized variables like peak width statistics and decomposition of the raw spectrum in basic components.
Project done in collaboration with FERMI@Elettra
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB070  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB071 Considerations on Implementing EEHG with a Strong Linear Chirp 1830
SUSPFO093   use link to see paper's listing under its alternate paper code  
 
  • M.A. Pop, S. Werin
    MAX IV Laboratory, Lund University, Lund, Sweden
 
  As the ECHO enabled harmonic generation (EEHG) scheme draws such intense focus from the FEL community, we conduct simulations to evaluate the challenges of implementing said scheme in different FEL layouts. Nonlinear processes such as this require extensive simulations to harmonize all system specific properties like seed lasers and electron beam properties. Along with optimizing the original EEHG scheme* one can consider, for example, altering the seed laser pulse to optimize the bunching for a machine specific chirp. We study the EEHG as a possible seeding method aimed at increasing coherence of the photon beam for the prospective SXL FEL beamline at MAXIV. The particular chirp of the electron beam through the MAXIV LINAC generates some specific requirements in implementing EEHG but may also offer an opportunity for exotic operation modes of this FEL.
* Xiang D. and Stupakov G. Echo-enabled harmonic generation free electron laser 10.1103/PhysRevSTAB.12.030702
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB071  
About • paper received ※ 15 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB074 Start-to-End Simulations of the Compact Light Project Based on an S-Band Injector and an X-Band LINAC 1836
 
  • E. Marín, R. Muñoz Horta, F. Pérez
    ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
  • A.A. Aksoy
    Ankara University, Accelerator Technologies Institute, Golbasi, Turkey
  • S. Di Mitri
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • A. Latina
    CERN, Geneva, Switzerland
  • S.B. van der Geer
    Pulsar Physics, Eindhoven, The Netherlands
 
  Funding: This project has received funding from the European Union’s Horizon2020 research and innovation programme under grant agreement No 777431
In this paper we report the start-to-end simulation results of one of the options under consideration for the CompactLight Project (XLS). The XLS is a hard X-ray Free Electron Laser under design, using the latest concepts for bright electron photo injectors, very high-gradient X-band structures, and innovative short-period undulators. Presently there exist various tracking codes to conduct the design process. Therefore identifying the most convenient code is of notable importance. This paper compares the tracking codes, Placet and General Particle Tracer, using the XLS lattice based on a S and X-band Injector. The calculation results in terms of beam quality and tracking performance of a full 6-D simulation are presented.
[*] The CompactLight Design Study Project, IPAC2019 proceedings.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB074  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB075 Higher Order Mode Spectra Study of 3.9 GHz Superconducting Radio Frequency Cavities for the European XFEL 1840
 
  • L. Shi, S. Reiche
    PSI, Villigen PSI, Switzerland
  • N. Baboi, A.A. Sulimov, E. Vogel, T. Wamsat
    DESY, Hamburg, Germany
  • R.M. Jones, N.Y. Joshi
    UMAN, Manchester, United Kingdom
  • P. Pierini
    ESS, Lund, Sweden
 
  Funding: The work is part of EuCARD2 and was partly funded by the European Commission, GA 312453.
It is important to verify both by simulation and experiments the wakefields in superconducting radio frequency (SRF) cavities, which can degrade the electron beam quality considerably or impose excessive heat load if left undamped. In this paper, we investigate the Higher Order Mode (HOM) spectra of the 3.9 GHz SRF cavities, which are assembled in a cryogenic module and are used to linearize the longitudinal phase space of the electron beam in the injector of the European XFEL. The HOM spectra are significantly different from the ones from a single cavity due to the coupling of the modes amongst cavities. The measurements not only provide direct input for the beam dynamics studies but also for the beam instrumentation utilizing these modes. The mode spectra are also investigated with a number of numerical simulations and the comparison with measurements shows favorable agreement.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB075  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB076 Free Electron Laser Driven by a High-Energy High-Current Energy-Recovery Linac 1844
 
  • F. Zimmermann
    CERN, Geneva, Switzerland
  • H. Aksakal
    KMSIU, Onikisubat / Kahramanmaras, Turkey
  • A.A. Aksoy
    Ankara University, Accelerator Technologies Institute, Golbasi, Turkey
  • Z. Nergiz
    Nigde University, Nigde University Science & Art Faculty, Nigde, Turkey
 
  Funding: This work was supported by the European Commission under the HORIZON 2020 project ARIES, grant agreement no. 730871.
The proposed electron-hadron collider LHeC, based on an energy recovery linac, employs an electron beam of 20 mA current at an energy of tens of GeV. This electron beam could also be used to drive a free electron laser (FEL) operating at sub-Angstrom wavelengths. Here we demonstrate that such FEL would have the potential to provide orders of magnitude higher peak power, peak brilliance and average brilliance, than any other FEL, either existing or proposed.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB076  
About • paper received ※ 10 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB083 Status of Clara Front End Commissioning and First User Experiments 1851
 
  • D. Angal-Kalinin, A.D. Brynes, R.K. Buckley, S.R. Buckley, R.J. Cash, H.M. Castaneda Cortes, J.A. Clarke, P.A. Corlett, L.S. Cowie, K.D. Dumbell, D.J. Dunning, B.D. Fell, P. Goudket, A.R. Goulden, S.A. Griffiths, J. Henderson, F. Jackson, J.K. Jones, N.Y. Joshi, S.L. Mathisen, J.W. McKenzie, K.J. Middleman, B.L. Militsyn, A.J. Moss, B.D. Muratori, T.C.Q. Noakes, T.H. Pacey, M.D. Roper, Y.M. Saveliev, D.J. Scott, B.J.A. Shepherd, R.J. Smith, E.W. Snedden, M. Surman, N. Thompson, C. Tollervey, R. Valizadeh, D.A. Walsh, T.M. Weston, A.E. Wheelhouse, P.H. Williams
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A.D. Brynes, J.A. Clarke, K.D. Dumbell, D.J. Dunning, P. Goudket, F. Jackson, J.K. Jones, J.W. McKenzie, K.J. Middleman, B.L. Militsyn, A.J. Moss, B.D. Muratori, T.C.Q. Noakes, Y.M. Saveliev, D.J. Scott, B.J.A. Shepherd, M. Surman, N. Thompson, R. Valizadeh, A.E. Wheelhouse, P.H. Williams
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • R.F. Clarke, G. Cox, M.D. Hancock, J.P. Hindley, C. Hodgkinson, A. Oates, W. Smith, J.T.G. Wilson
    STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
  • L.S. Cowie
    Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
  • N.Y. Joshi, T.H. Pacey
    UMAN, Manchester, United Kingdom
 
  CLARA (Compact Linear Accelerator for Research and Applications) is a test facility for Free Electron Laser (FEL) research and other applications at STFC’s Daresbury Laboratory. The first exploitation period using CLARA Front End (FE) provided a range of beam parameters to 12 user experiments. Beam line to Beam Area 1 (BA1) was commissioned and optimised for these experiments, some involving TW laser integration. In addition to the user exploitation programme, significant advances were made to progress on machine development. This paper summarises these developments and presents the near future plan for CLARA.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB083  
About • paper received ※ 14 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB084 High Level Software Development Framework and Activities on VELA/CLARA 1855
 
  • D.J. Scott, A.D. Brynes, M.P. King
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
  • A.D. Brynes, D.J. Scott
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
 
  The success of modern particle accelerators depends on good high level software. Over the past few years an integrated framework has been developed to better connect machine physicists to VELA/CLARA at the STFC’s Daresbury laboratory. This framework is comprised of a number of tools, including, a c++/Python API to interface to the EPICS control system with which all High Level Software can be developed. The API is encapsulated, extensible and designed to grow as further Phases of CLARA are installed. The API is seamlessly integrated with the VELA/CLARA virtual accelerator and other activities by the simulations group. As well as presenting the design choices and methodology we will give an overview of the first control room applications built using our tools and how they will form the basis for a new programme of machine learning and optimisation on CLARA.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB084  
About • paper received ※ 14 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB086 Four X-ray Pulses within 10 ns at LCLS 1859
 
  • F.-J. Decker, W.S. Colocho, S.H. Glenzer, A.A. Lutman, A. Miahnahri, D.F. Ratner, J.C. Sheppard, S. Vetter
    SLAC, Menlo Park, California, USA
 
  The X-Ray FEL at SLAC or LCLS delivers typically one bunch at the time. Different schemes of two bunches have been developed: Two bucket, Twin bunch, split undulator, and fresh slice. Here we discuss a four bunch or even eight bunch setup, separated by 2 RF buckets or 0.7 ns. . The demand comes from MEC (Matter in Extreme Conditions) experiments, where high-power laser beams with Joule-class energies create impulsive pressure waves compressing materials on time scales of the order of ns. Eight snapshots for a single experiment will allow measuring the compression history, structural phase transitions into new high-pressure material states, and have the potential to resolve the transition kinetics time scales.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB086  
About • paper received ※ 30 April 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB088 Generation of High Peak Power Hard X-Rays at LCLS-II with Double Bunch Self-seeding 1863
 
  • A. Halavanau, F.-J. Decker, Y. Ding, C. Emma, Z. Huang, J. Krzywiński, A.A. Lutman, G. Marcus, C. Pellegrini, D. Zhu
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515.
We propose to use existing LCLS copper S-band linac double bunch infrastructure to significantly improve LCLS-II hard X-ray performance. In our setup, we use the first bunch to generate a strong seeding X-ray signal, and the second bunch, initially traveling off-axis, to interact with the seed in the amplifier undulator and generate a near TW, 15 fs duration X-ray pulse in the 4 to 8 keV photon energy range. We investigate, via numerical simulations, the required transverse beam dynamics and the four crystals X-ray monochromator to be added to the existing LCLS-II beamline and discuss the final properties of the hard X-ray pulses and their potential application in high intensity, high-field physics experiments, including QED above the Schwinger critical field.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB088  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB089 Undulator Radiation Generated by a Single Electron 1867
 
  • A. Halavanau, Z. Huang, C. Pellegrini, T.O. Raubenheimer
    SLAC, Menlo Park, California, USA
  • I. Lobach
    University of Chicago, Chicago, Illinois, USA
  • S. Nagaitsev
    Fermilab, Batavia, Illinois, USA
  • D. Seipt
    HZDR, Dresden, Germany
 
  Funding: This work was supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515.
The facilities providing single electron beams are currently being commissioned at Fermilab and will be at SLAC. Recently, Fermilab’s IOTA ring routinely demonstrated circulation of a single electron at 100 MeV beam energy. Alternatively, SLAC is working on constructing LCLS-II an X-ray FEL driven by a 4 GeV SRF linac. A parasitic beamline, S30XL, is planned that will extract 4 GeV dark current from between the primary LCLS-II electron bunches. The dark current will be delivered to End Station A and can work independently of LCLS-II experiments. The dark current will be bunched at a frequency of 46 MHz while extracted current varied from single electrons to 10’s of nA. In the present paper, we estimate the feasibility of propagating single electron beams through a conventional undulator, placed in the IOTA and S30XL beamlines. We explore the possible observable effects and experimental parameters range. In addition, we focus on potential applications of such beams in systems for high fidelity quantum measurements.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB089  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB090 Preliminary Considerations of Atomic Inner-Shell X-Ray Laser for Self-Seeding at LCLS-II 1871
 
  • A. Halavanau, C. Pellegrini, J. Wu
    SLAC, Menlo Park, California, USA
  • A.I. Benediktovitch
    EuXFEL, Hamburg, Germany
  • N. Rohringer
    Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
 
  Funding: This work was supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515.
The atomic inner-shell X-ray lasing, induced by the irradiation of focused XFEL SASE pulses, was demonstrated in gases, liquid jets and solids. In this proceeding, we discuss the possible use of this concept in self-seeding scheme at LCLS-II. We provide a preliminary study of different lasing media and corresponding SASE XFEL parameters. For the case of noble gas inner-shell X-ray laser, we study the requirements for gas pressure and XFEL pulse focusing. Finally, we discuss possible designs of this system and its advantages in LCLS-II operations.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB090  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB091 Study of XFEL Third Harmonic Radiation at LCLS 1875
 
  • C. Emma, M.W. Guetg, A. Halavanau, A.A. Lutman, G. Marcus, T.J. Maxwell, C. Pellegrini
    SLAC, Menlo Park, California, USA
 
  Funding: This work was supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515.
In this paper, we focus on characterization of the nonlinear third harmonic radiation properties at Linac Coherent Light Source (LCLS). In addition, we experimentally perform third harmonic self-seeding, using diamond crystal attenuator in the hard X-ray self-seeding chicane. We discuss warm beam effects in such scheme, justifying recently proposed two bunch configuration for harmonic lasing.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB091  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB096 Test of an X-ray Cavity using Double-Bunches from the LCLS Cu-Linac 1887
 
  • K.-J. Kim, L. Assoufid, R.R. Lindberg, X. Shi, D. Shu, Yu. Shvyd’ko, M. White
    ANL, Argonne, Illinois, USA
  • F.-J. Decker, Z. Huang, G. Marcus, T.O. Raubenheimer, D. Zhu
    SLAC, Menlo Park, California, USA
 
  Funding: This work is supported by U.S. DOE, Office of Science, Office of BES, under Contract No. DE-AC02-06CH11357 (ANL) and DE-AC02-76SF00515 (SLAC).
We discuss a proposal to test the operation of an X-ray cavity consisting of Bragg reflectors. The test will con-stitute a major step demonstrating the feasibility of either an X-ray regenerative amplifier FEL or an X-ray FEL Oscillator. These cavity-based X-ray FELs will provide the full temporal coherence lacking in the SA-SE FELs. An X-ray cavity of rectangular path will be constructed around the first seven LCLS-II undulator units. The Cu-linac will produce a pair of electron bunches separated by the cavity-round-trip distance during each linac cycle. The X-ray pulse produced by the first bunch is deflected into the cavity and returns to the undulator where it is amplified due to the presence of the second bunch. The key challenges are: the preci-sion of the cavity mechanical construction, the quality of the diamond crystals, and the electron beam stability. When the LCLS-II super-conducting linac becomes available, the cavity can then be used for high-repetition rate studies of the X-ray RAFEL and XFELO concepts.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB096  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB097 Recent Progress on the Design of Normal Conducting APEX-II VHF CW Electron Gun 1891
 
  • D. Li, H.Q. Feng, D. Filippetto, M.J. Johnson, A.R. Lambert, T.H. Luo, C.E. Mitchell, J. Qiang, F. Sannibale, J.W. Staples, S.P. Virostek, R.P. Wells
    LBNL, Berkeley, California, USA
  • H.Q. Feng
    TUB, Beijing, People’s Republic of China
 
  Funding: Director of Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
We report recent progress on the design of a normal conducting CW electron gun, APEX-II (Advanced Photo-injector EXperiment-II) at Lawrence Berkeley National Laboratory. APEX-II is an upgrade of the successful APEX gun and the LCLS-II (Linac Coherent Light Source-II) injector, aiming at applications for Free electron laser (FEL) such as LCLS-II High Energy upgrade, UED (Ultrafast Electron Diffraction) and UEM (Ultrafast Electron Microscopy). The APEX-II adopted a two-cell cavity design with resonant frequency of 162.5 MHz. The APEX-II gun is targeting to achieve exceeding 30 MV/m of launch gradient at the cathode and output energy above 1.5 MeV with transverse emittance of 0.1 um at 100 pC. Advanced MOGA optimization technique has been used for both the RF cavity design and extensive beam dynamics studies using APEX-like and LCLS-II like injector layout. Detailed RF designs, beam dynamics studies, preliminary engineering design and FEA analysis will be presented, with cavity features that were demonstrated to be crucial in the operation of the APEX gun.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB097  
About • paper received ※ 15 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB103 The FHI FEL Upgrade Design 1903
 
  • A.M.M. Todd
    AMMTodd Consulting, Princeton Junction, New Jersey, USA
  • W.B. Colson
    NPS, Monterey, California, USA
  • M. De Pas, S. Gewinner, H. Junkes, G. Meijer, W. Schöllkopf, G. von Helden
    FHI, Berlin, Germany
  • S.C. Gottschalk
    STI Magnetics LLC, Woodinville, USA
  • J. Rathke, T. Schultheiss
    AES, Medford, New York, USA
  • L.M. Young
    LMY Technology, Lincolnton, Georgia, USA
 
  Since coming on-line in November 2013, the Fritz-Haber-Institut (FHI) der Max-Planck-Gesellschaft (MPG) Free-Electron Laser (FEL) has provided intense, tunable infrared radiation to FHI user groups. It has enabled experiments in diverse fields ranging from bio-molecular spectroscopy to studies of clusters and nanoparticles, nonlinear solid-state spectroscopy, and surface science, resulting in 50 peer-reviewed publications so far. The MPG has now funded a significant upgrade to the original FHI FEL. A second short Rayleigh range undulator FEL beamline is being added that will permit lasing from < 5 microns to > 160 microns. Additionally, a 500 MHz kicker cavity will permit simultaneous two-color operation of the FEL from both FEL beamlines over an optical range of 5 to 50 microns by deflecting alternate 1 GHz pulses into each of the two undulators. We will describe the upgraded FHI FEL physics and engineering design and present the plans for two-color FEL operations in November 2020.
A.M.M. Todd, L.M. Young, J.W Rathke, W.B. Colson, T.J Schultheiss and S. Gottschalk are Consultants to the Fritz-Haber-Institut
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB103  
About • paper received ※ 02 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB106 Status of the Superconducting Soft X-Ray Free-Electron Laser User Facility Flash at DESY 1909
 
  • J. Rönsch-Schulenburg, K. Honkavaara, M. Kuhlmann, S. Schreiber, R. Treusch, M. Vogt
    DESY, Hamburg, Germany
 
  FLASH, the free electron laser user facility at DESY (Hamburg, Germany), delivers high brilliance XUV and soft x-ray FEL radiation to photon experiments with different parameters at two undulator beamlines simultaneously. FLASH’s superconducting linac can produce bunch trains of up to 800 bunches within a 0.8 ms RF flat top at a repetition rate of 10 Hz. In standard operation during 2018, FLASH supplied up to 500 bunches in two bunch trains with independent fill patterns and compression schemes to each of the two beamlines. In 2018 first successful plasma accelerating experiments could be reported by the FLASHForward plasma wakefield acceleration experiment situated in a third beamline. We report on the highlights of FLASH operation in 2018/2019.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB106  
About • paper received ※ 13 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPRB108 Mechanical Design of a Dielectric Wakefield Dechirper System for CLARA 1912
 
  • M. Colling, D.J. Dunning, B.D. Fell, T.H. Pacey, Y.M. Saveliev
    STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
 
  STFC Daresbury Laboratory are developing a compact electron beam energy dechirper system, based on dielectric wakefield structure, for the on-site electron accelerator CLARA (Compact Linear Accelerator for Research and Applications). CLARA will be an experimental free electron laser (FEL) facility operating at 250MeV and will be a test bed for a variety of novel FEL schemes. The dechirper dielectric quartz plates will induce wakefields within the structure which can remove the beam chirp that is initially introduced to compress the electron bunch longitudinally. Removing or adjusting the amount of chirp enables researchers to reduce or adjust the bunch energy/momentum spread, expanding the FEL capabilities. The attachment and alignment of the quartz plates present numerous mechanical design challenges that require high precision manufacturing and quartz plate positioning via fiducialisation. This paper will review the dechirper specifications, the chosen design solutions, measured mechanical performance, and the expected effect of the dechirper on CLARA FEL operation.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB108  
About • paper received ※ 13 May 2019       paper accepted ※ 22 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEXPLM1 XFEL Operational Flexibility due to the Dechirper System 2219
 
  • A.A. Lutman, K.L.F. Bane, Y. Ding, C. Emma, M.W. Guetg, E. Hemsing, Z. Huang, J. Krzywiński, J.P. MacArthur, G. Marcus, A. Marinelli, T.J. Maxwell, A. Novokhatski
    SLAC, Menlo Park, California, USA
  • G. Guo
    Stanford University, Stanford, California, USA
 
  Funding: U.S.Department of Energy, Office of Science, Laboratory Directed Research and Development (LDRD) program at SLAC National Accelerator Laboratory, under Contract No. DE-AC02-76SF00515.
The RadiaBeam/SLAC dechirper was installed to demonstrate the concept of using wakefields from a corrugated structure to change the energy profile along an electron bunch. Since installation, the system has allowed a large number of additional XFEL operating modes including fresh-slice two-color or three color operation, fresh-slice seeding, passive streaking, etc. This talk will discuss the results from using the dechirper system and possible implementation issues related to the high-rate LCLS-II.
Lutman, A. A. et al. Nat. Photon. 10, 745-750 (2016).; Nat. Photon. 10, 695-696 (2016); other papers in submission.
 
slides icon Slides WEXPLM1 [5.744 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEXPLM1  
About • paper received ※ 10 May 2019       paper accepted ※ 20 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEXXPLM1 Amplified Emission of a Soft-X Ray Free-Electron Laser Based on Echo-Enabled Harmonic Generation 2230
 
  • E. Allaria, L. Badano, G. De Ninno, S. Di Mitri, B. Diviacco, W.M. Fawley, N.S. Mirian, G. Penco, P. Rebernik Ribič, S. Spampinati, C. Spezzani, M. Trovò
    Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
  • G. De Ninno
    University of Nova Gorica, Nova Gorica, Slovenia
  • E. Ferrari, E. Prat
    PSI, Villigen PSI, Switzerland
  • D. Garzella
    CEA, Gif-sur-Yvette, France
  • V. Grattoni
    DESY, Hamburg, Germany
  • E. Hemsing
    SLAC, Menlo Park, California, USA
  • M.A. Pop
    MAX IV Laboratory, Lund University, Lund, Sweden
  • E. Roussel
    PhLAM/CERLA, Villeneuve d’Ascq, France
  • D. Xiang
    Shanghai Jiao Tong University, Shanghai, People’s Republic of China
 
  We report the first evidence of substantial gain in a soft-X ray Free Electron Laser (FEL) based on Echo-Enabled Harmonic Generation (EEHG). The experiment was focused on harmonics 36 (~7.3nm) and 45 (5.8 nm) and clearly demonstrated the expected EEHG capability of generating powerful and coherent FEL pulses, with strongly reduced sensitivity to electron-beam fluctuations. The experiment was carried out at FERMI, the seeded FEL user facility at Elettra-Sincrotrone Trieste.  
slides icon Slides WEXXPLM1 [11.410 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEXXPLM1  
About • paper received ※ 17 May 2019       paper accepted ※ 23 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
WEXXPLM2
Slippage Boosted Spectral Cleaning in a Seeded Free-Electron Laser  
 
  • C. Feng
    SARI-CAS, Pudong, Shanghai, People’s Republic of China
 
  The realization of fully coherent X-ray radiation pulse has been a long-standing challenge for free-electron lasers. A promising way for producing stable transform-limited pulses is based on the harmonic up-conversion techniques with a conventional laser as the seed. However, it is found that the insignificant phase error in the seed laser will be eventually multiplied by the harmonic number, leading to a degradation of the output temporal coherence at short wavelength. Here, we report the demonstration of a slippage boosted spectral cleaning technique to mitigate the impact of seed laser induced phase errors and to improve the temporal coherence of a seeded FEL. Experimental results show that fully coherent radiation pulses can be generated in a seeded FEL with the help of the proposed technique.  
slides icon Slides WEXXPLM2 [4.915 MB]  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)