Author: Rehm, G.
Paper Title Page
MOP02 An Optical Diagnostic Beamline for the Bessy II Booster 19
  • T. Atkinson, J.-G. Hwang, G. Rehm, M. Ries, G. Schiwietz, S. Wiese
    HZB, Berlin, Germany
  As part of the global refurbishment of the injector at BESSY II, a new optical beamline has been installed in the booster. This paper covers the conceptual design: incorporating the beamline into an operational facility without downtime, the simulation and expectations of the optical transport line, mechanical installation and commissioning with beam. These first results with the present beam delivery system have already achieved source point imaging and bunch length measurements using a fast diode. With the additional PETRA cavity installed for this booster upgrade and connection to acquire RF power in the 2022 summer shutdown planned, the bunch length diagnostics are critical. The beamline will also undergo a final mechanical upgrade and then see the installation of a streak camera.  
poster icon Poster MOP02 [0.975 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-IBIC2022-MOP02  
About • Received ※ 05 September 2022 — Revised ※ 09 September 2022 — Accepted ※ 11 December 2022 — Issue date ※ 12 December 2022
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MOP18 X-Ray Pinhole Camera Spatial Resolution Using High Aspect Ratio LIGA Pinhole Apertures 71
  • N. Vitoratou, L. Bobb
    DLS, Oxfordshire, United Kingdom
  • A. Last
    KIT, Eggenstein-Leopoldshafen, Germany
  • G. Rehm
    HZB, Berlin, Germany
  X-ray pinhole cameras are employed to provide the transverse profile of the electron beam from which the emittance, coupling and energy spread are calculated in the storage ring of Diamond Light Source. Tungsten blades separated by shims are commonly used to form the pinhole aperture. However, this approach introduces uncertainties regarding the aperture size. X-ray lithography, electroplating and moulding, known as LIGA, has been used to provide thin screens with well-defined and high aspect ratio pinhole apertures. Thus, the optimal aperture size given the beam spectrum can be used to improve the spatial resolution of the pinhole camera. Experimental results using a LIGA screen of different aperture sizes have been compared to SRW-Python simulations over the 15-35 keV photon energy range. Good agreement has been demonstrated between the experimental and the simulation data. Challenges and considerations for this method are also presented.  
poster icon Poster MOP18 [0.600 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-IBIC2022-MOP18  
About • Received ※ 08 September 2022 — Revised ※ 09 September 2022 — Accepted ※ 13 September 2022 — Issue date ※ 21 November 2022
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Review of BPM Drift Effects and Compensation Schemes  
  • G. Rehm
    HZB, Berlin, Germany
  Apart from short term BPM resolution (repeatability), which aims at a few nm / sqrt(Hz) in modern systems, medium to long-term drift over durations of seconds to weeks (reproducibility) represents one of the challenges for BPM electronic developments. A number of approaches and compensation schemes have been developed and tested during the past years (e.g. cross-bar switching, pilot tone compensation, active temperature stabilization etc.) and experience has been gathered with environmental effects on electronics, cables and connectors. This talk will provide a review of drift effects and mitigation schemes for the next generation BPM systems.  
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slides icon Slides MO3I1 [6.535 MB]  
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TUP43 Requirements and Design for the PETRA IV Fast Orbit Feedback System 343
  • S.H. Mirza, A. Aloev, H.T. Duhme, B. Dursun, A. Eichler, S. Jabłoński, J. Klute, F. Ludwig, S. Pfeiffer, H. Schlarb, B. Szczepanski
    DESY, Hamburg, Germany
  • G. Rehm
    HZB, Berlin, Germany
  PETRA IV is the upcoming low-emittance, 6 GeV, fourth- generation light source at DESY Hamburg. It is based upon a six-bend achromat lattice with additional beamlines as compared to PETRA III. Stringent stability of the electron beam orbit in the ring will be required to achieve diffraction- limited photon beam quality. In this regard, the requirements and the proposed topology of the global orbit feedback system are discussed for expected perturbations. An initial analysis based upon system requirements, design and modelling of the subsystems of the orbit feedback system is also presented  
poster icon Poster TUP43 [0.923 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-IBIC2022-TUP43  
About • Received ※ 14 September 2022 — Revised ※ 25 October 2022 — Accepted ※ 01 December 2022 — Issue date ※ 03 December 2022
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WEP31 Booster Fillpattern Monitor 473
  • F. Falkenstern, J. Kuszynski, G. Rehm
    HZB, Berlin, Germany
  The "Booster Fillpattern Monitor" is used to measure currents in each individual electron bunch in the booster of the BESSY II machine. The booster with its circumference of 96 meters has space for max.160 electron bunches. The distance between the electron bunches of 60cm (96m/160) is determined by the RF Master Clock ~ 499, 627MHz. In practice, fill patterns of a one to five equally spaced bunches are in use. The fill pattern monitor digitizes electrical pulses generated from a strip line using a broadband ADC. The sampling frequency is selected as an integer fraction of the bunching frequency, acquiring the full fill pattern over a number of turns. Experiments performed at BESSY II demonstrate the performance of the setup and will be discussed.  
DOI • reference for this paper ※ doi:10.18429/JACoW-IBIC2022-WEP31  
About • Received ※ 06 September 2022 — Revised ※ 12 September 2022 — Accepted ※ 13 September 2022 — Issue date ※ 24 October 2022
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