Author: Floettmann, K.    [Flöttmann, K.]
Paper Title Page
TUPOMS044 Dielectric Loaded THz Waveguide Experimentally Optimized by Dispersion Measurements 1526
SUSPMF027   use link to see paper's listing under its alternate paper code  
 
  • M.J. Kellermeier, R.W. Aßmann, K. Flöttmann, F. Lemery
    DESY, Hamburg, Germany
  • R.W. Aßmann
    LNF-INFN, Frascati, Italy
  • W. Hillert
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
 
  Emerging high power THz sources pave the road for THz- driven acceleration of ultra-short bunches, and enable their manipulation for diagnostic purposes. Due to the small feature sizes of THz-guiding devices new methods are necessary for their electromagnetic characterization. A new technique has recently been developed which characterizes THz waveguides with respect to their dispersion relations and attenuation. Here, the method is applied to circular waveguides, partially filled with polymer capillaries of different thicknesses, to find a suitable size for THz driven streaking at 287 GHz. Further, rough 3d-printed metallic waveguides are measured to study the effect of roughness on attenuation and phase constant. In general, additive manufacturing techniques show promise for advanced integrated designs of THz driven structures.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOMS044  
About • Received ※ 05 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 28 June 2022
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WEPOPT046 Preparation of a Prototype Plasma Lens as an Optical Matching Device for the ILC e+ Source 1961
 
  • M. Formela, N. Hamann, G.A. Moortgat-Pick
    University of Hamburg, Hamburg, Germany
  • K. Flöttmann, G. Loisch, G.A. Moortgat-Pick
    DESY, Hamburg, Germany
 
  In recent years, high-gradient, symmetric focusing with active plasma lenses has regained significant interest due to the potential advantages in compactness and beam dynamics compared to conventional focusing elements. One potential application is the optical matching of highly divergent positrons from the undulator-based ILC positron source into the downstream accelerating structures. A collaboration between University Hamburg and DESY Hamburg has been established to develop a prototype design for this application. Here, we discuss beam dynamics simulation results, preliminary parameters of the lens prototype, and the current status of the prototype design.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT046  
About • Received ※ 07 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 17 June 2022
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WEPOTK037 Radiation of a Particle Moving Along a Helical Trajectory in a Resistive-Wall Cylindrical Waveguide 2150
 
  • M. Ivanyan, A. Grigoryan, B. Grigoryan, B.K. Sargsyan
    CANDLE SRI, Yerevan, Armenia
  • K. Flöttmann, F. Lemery
    DESY, Hamburg, Germany
  • A. Grigoryan
    YSU, Yerevan, Armenia
 
  Funding: The work was supported by the Science Committee of RA, in the frames of the research project 21T-1C239
The radiation field of a particle moving on a helical trajectory in a cylindrical waveguide with resistive walls is calculated. The deformation of the energy spectrum of radiation, as a result of the finite conductivity of the walls, is investigated.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK037  
About • Received ※ 31 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 30 June 2022
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WEPOTK039 Radiation of a Particle Moving Along a Helical Trajectory in a Semi-Infinite Cylindrical Waveguide 2154
 
  • M. Ivanyan, A. Grigoryan, B. Grigoryan, V.G. Khachatryan, B.K. Sargsyan
    CANDLE SRI, Yerevan, Armenia
  • K. Flöttmann, F. Lemery
    DESY, Hamburg, Germany
  • A. Grigoryan
    YSU, Yerevan, Armenia
 
  Funding: The work was supported by the Science Committee of RA, in the frames of the research project 21T-1C239
The radiation field of a particle which suddenly appears in an ideal waveguide and moves on a helical trajectory under the influence ofexternal magnetic fields is calculated. The shape and character of the front of the propagating wave is determined. The time dependence of radiation energy accumulated in the waveguide is investigated.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK039  
About • Received ※ 31 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 05 July 2022 — Issue date ※ 06 July 2022
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THPOPT005 Field Enhanced, Compact S-Band Gun Employing a Pin Cathode 2567
SUSPMF020   use link to see paper's listing under its alternate paper code  
 
  • R. Bazrafshan, T. Rohwer
    Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany
  • M. Fakhari, K. Flöttmann, F.X. Kaernter
    DESY, Hamburg, Germany
  • N.H. Matlis
    CFEL, Hamburg, Germany
 
  S-band RF-guns are highly developed for production of low emittance relativistic electron bunches, but need powerful klystrons for driving. Here, we present the design and first experimental tests of a compact S-band gun, which can accelerate electrons up to 180 keV powered by only 10 kW from a compact rack-mountable solid-state amplifier. A pin-cathode is used to enhance the RF electric field on the cathode up to 100 MV/m as in large-scale S-band guns. An electron bunch is generated through photoemission off a flat copper surface on the pin excited by a UV laser pulse followed by a focusing solenoid producing a low emittance bunch with 0.1 mm mrad transverse emittance for up to 100 fC bunch charge. We are currently in the conditioning phase of the gun and first experiments show good agreement with simulations. The compact gun will serve three purposes: (i) it can be used directly for ultrafast electron diffraction; (ii) as an injector into a THz booster producing 0.3MeV to 2 MeV electron bunches for ultrafast electron diffraction; (iii) The system in (ii) serves as an injector into a THz linear accelerator producing a 20 MeV beam for the AXSIS X-ray source project.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT005  
About • Received ※ 21 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022
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