Author: Khan, S.
Paper Title Page
MOPMK014 Resistive-Wall Impedance of Insertions for FCC-hh 378
 
  • B. Riemann, S. Khan
    DELTA, Dortmund, Germany
  • S. Arsenyev, D. Schulte
    CERN, Geneva, Switzerland
  
  Funding: This work is supported by the German Ministry of Education & Research (BMBF, funding code 05P15PERB1) and CERN (reference numbers KE3123, EDMS 1606722).
In this work, transverse and longitudinal resistive-wall impedances for beam pipes in the experiment, injection, extraction and RF systems insertion regions of the Future Hadron-Hadron Collider (FCC-hh) are computed based on contributions from different given cross sections of the surrounding (elliptical) chamber parts along the beam path, their temperature-dependent conductivities, and optical functions. An emphasis is placed on the behaviour of transverse impedance in the main experimental regions (A and G), where maximum beta values of 104 to 105 m occur in dependence of the operation mode respectively lattice configuration. Main contributions to the transverse and longitudinal impedance budget are identified, and possibilities of reducing them are discussed. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK014  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMF078 Control of FEL Radiation Properties by Tailoring the Seed Pulses 1444
 
  • V. Grattoni, R.W. Aßmann, J. Bödewadt, I. Hartl, C. Lechner, B. Manschwetus, M.M. Mohammad Kazemi
    DESY, Hamburg, Germany
  • A. Azima, W. Hillert, V. Miltchev, J. Roßbach
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  • S. Khan, T. Plath
    DELTA, Dortmund, Germany
  
  Seeded free-electron lasers (FELs) produce intense, ultrashort and fully coherent X-ray pulses. These seeded FEL pulses depend on the initial seed properties. Therefore, controlling the seed laser allows tailoring the FEL radiation for phase-sensitive experiments. In this contribution, we present detailed simulation studies to characterize the FEL process and to predict the operation performance of seeded pulses. In addition, we show experimental data on the temporal characterization of the seeded FEL pulses performed at the sFLASH experiment in Hamburg.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF078  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMF079 An Option to Generate Seeded FEL Radiation for FLASH1 1448
 
  • V. Grattoni, R.W. Aßmann, J. Bödewadt, I. Hartl, C. Lechner, B. Manschwetus, M.M. Mohammad Kazemi
    DESY, Hamburg, Germany
  • W. Hillert, V. Miltchev, J. Roßbach
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  • S. Khan, T. Plath
    DELTA, Dortmund, Germany
  
  The FLASH free-electron laser (FEL) at DESY is currently operated in self-amplified spontaneous emission (SASE) mode in both beamlines FLASH1 and FLASH2. Seeding offers unique properties for the FEL pulse, such as full coherence, spectral and temporal stability. In this contribution, possible ways to carry the seeded FEL radiation to the user hall are presented with analytical considerations and simulations. For this, components of the sFLASH seeding experiment are used.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF079  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
TUPMF085 Status of the sFLASH Experiment 1471
 
  • C. Lechner, R.W. Aßmann, J. Bödewadt, V. Grattoni, I. Hartl, T. Laarmann, M.M. Mohammad Kazemi, A. Przystawik
    DESY, Hamburg, Germany
  • A. Azima, H.B. Biss, M. Drescher, W. Hillert, L.L. Lazzarino, V. Miltchev, J. Roßbach
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  • S. Khan, T. Plath
    DELTA, Dortmund, Germany
  
  Funding: This work is supported by the Federal Ministry of Education and Research of Germany within FSP-302 under FKZ 05K13GU4, 05K13PE3, and 05K16PEA.
The sFLASH experiment at the free-electron laser (FEL) FLASH1 is a setup for the investigation of external FEL seeding. Since 2015, the seeding scheme high-gain harmonic generation (HGHG) is being studied. At the end of the seeded FEL, an RF deflector enables time-resolved analysis of the seeded electron bunches while the photon pulses can be characterized using the technique of THz streaking. In this contribution, we present the current configuration of the experiment and give an overview of recent experimental results. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF085  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMK097 First Conceptual Design Studies of an Electron Source for Ultrafast Electron Diffraction at DELTA 4530
 
  • D. Krieg, S. Khan
    DELTA, Dortmund, Germany
  • K. Sokolowski-Tinten
    Universität Duisburg-Essen, Duisburg, Germany
  
  Funding: MERCUR Pr-2017-0002
Ultrafast electron diffraction (UED) is a technique to study the structural dynamics of matter, combining diffraction of electrons with sub-angstrom De-Broglie wavelength with femtosecond time resolution. The method is complementary to X-ray scattering at free-electron lasers. UED pump-probe experiments require ultrashort laser pulses to pump a sample, electron bunches with small emittance and ultrashort length to analyze the state of the sample by diffraction, as well as excellent control of the delay between them. While most UED systems are based on electrostatic electron sources in the keV regime, electrons accelerated to a few MeV in a radiofrequency photocathode gun offer significant advantages regarding emittance and bunch length due to the reduction of space charge effects. Furthermore, the longer mean free path of MeV electrons allows for thicker samples and hence a broader range of possible materials. In this paper, a first conceptual design and simulation results for a university-based UED facility with ultrashort and low-emittance MeV electron bunches are presented. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK097  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMK098 A Tunable Narrowband Source in the Sub-THz and THz Range at DELTA 4534
 
  • C. Mai, B. Büsing, S. Khan, A. Meyer auf der Heide, B. Riemann, B. Sawadski, P. Ungelenk
    DELTA, Dortmund, Germany
  • M. Brosi, J.L. Steinmann
    KIT, Karlsruhe, Germany
  • F. Frei
    PSI, Villigen PSI, Switzerland
  • C. Gerth
    DESY, Hamburg, Germany
  • M. Laabs, N. Neumann
    TU Dresden, Dresden, Germany
  • N.M. Lockmann
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  
  Funding: Work supported by the DFG (INST 212/236-1 FUGG), the BMBF (05K13PEC, 05K16PEB) and the state of NRW.
At DELTA, a 1.5-GeV electron storage ring operated as a synchrotron light source by the TU Dortmund University, an interaction of ultrashort laser pulses with electron bunches is used to generate broadband as well as tunable narrowband radiation in the frequency range between 75 GHz and 5.6 THz. The performance of the source was studied using two different Fourier-transform spectrometers. It was demonstrated that the source can be used for the characterization and comparison of Schottky-diode based detectors, e.g., an on-chip spectrometer enabling single-shot applications. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK098  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPMK099 Measurement of the Laser-Induced Energy Modulation Amplitude at the Short-Pulse Facility at DELTA 4538
 
  • A. Meyer auf der Heide, B. Büsing, S. Khan, N.M. Lockmann, C. Mai, B. Riemann, B. Sawadski
    DELTA, Dortmund, Germany
  
  The short-pulse facility at the synchrotron light source DELTA operated by the TU Dortmund University employs coherent harmonic generation (CHG) to provide ultrashort pulses in the vacuum ultraviolet and terahertz regime. Here, a laser-electron interaction results in a modulation of the electron energy which is transformed into a density modulation by a magnetic chicane. Measurements of the energy modulation amplitude with different techniques including an RF phase modulation are presented. A combination of the results allow to estimate the energy spread of the electron beam.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK099  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)  
 
THPML084 Validating the COBEA Algorithm at the DELTA Storage Ring 4851
 
  • B. Riemann, B.D. Isbarn, S. Khan, S. Koetter, T. Weis
    DELTA, Dortmund, Germany
  
  Closed-Orbit Bilinear-Exponential Analysis (COBEA) is an algorithm to decompose monitor-corrector response matrices into (scaled) beta optics values, phase advances, scaled dispersion and betatron tunes. No explicit magnetic lattice model is required for COBEA - only the sequence of monitors and correctors along the beam path (no lengths, no strengths approach). To obtain absolute beta values, the length of one drift space can be provided as optional input. In this work, the application of COBEA to the DELTA storage ring, operated by TU Dortmund University, is discussed, and its results for betatron tunes and scaled dispersion are compared with those of conventional, direct measurement methods. COBEA is also put in a historical perspective to other diagnostic algorithms. Improvements in the Python implementation of COBEA, which is available as free software, are presented. Due to COBEA being relatively modest regarding its requirements on input data respectively hardware, it should be applicable to the majority of existing storage rings.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML084  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)