Author: Ries, M.
Paper Title Page
TUOAB02 Simultaneous Long and Short Bunch Operation in an Electron Storage Ring - a Hybrid Mode based on Nonlinear Momentum Compaction 945
  • M. Ries, J. Feikes, A. Jankowiak, P.O. Schmid, G. Wüstefeld
    HZB, Berlin, Germany
  The generation of short pulses in electron storage rings is driven by different user groups like time resolved x-ray spectroscopy users or users of coherent synchrotron radiation. The required optics and operation conditions to generate this short bunches are worsening the experimental conditions, e.g. strongly reducing the average photon flux, for the regular user. Therefore short bunch operation is usually limited to dedicated user shifts. By controlling higher orders of the momentum compaction factor by higher multipoles it is possible to introduce a hybrid mode and simultaneously supplying long and short bunches*. The Metrology Light Source (MLS) has the means to control these higher orders**, therefore it is an ideal machine to investiate the feasibility of such a hybrid mode. Tracking results and first measurements will be shown.
* D. Robin et al., Proc. of EPAC08, p. 2100-2102, Genoa, Italy (2008).
** J. Feikes et al., Phys. Rev. ST Accel. Beams 14, 030705 (2011).
slides icon Slides TUOAB02 [7.817 MB]  
TUPC072 Accurate Electron Beam Size Measurement at the Metrology Light Source 1165
  • R. Klein, G. Brandt, R. Thornagel
    PTB, Berlin, Germany
  • J. Feikes, M. Ries, G. Wüstefeld
    HZB, Berlin, Germany
  For the operation of the Metrology Light Source (MLS)*, the dedicated electron storage ring of the Physikalisch-Technische Bundesanstalt (PTB), as the national primary radiation source standard from the near infrared to the vacuum ultraviolet spectral region, all storage ring parameters which are relevant for the calculation of the radiant intensity by the Schwinger equation have to be known absolutely with small uncertainties. For the measurement of the effective vertical electron beam size a Bragg polarimeter, operating at a photon energy of 1103 eV, has been designed and put into operation. This system also serves as a detection system for the image of the electron beam through a set of narrow slits. The results obtained with the new device are compared to those measured by an optical beam imaging system**.
* R. Klein et al., Phys. Rev. ST-AB 11, 110701 (2008).
** C. Koschitzki et al., Proc. IPAC10, 894-896 (2010).
THPC012 Mitigating the Pertubations Caused by U 180 at the Metrology Light Source 2930
  • P.O. Schmid, D.B. Engel, J. Feikes, M. Ries, G. Wüstefeld
    HZB, Berlin, Germany
  The Metrology Light Source is equipped with an electromagnetic undulator with a period length of 180 mm. User requests demand operation of this undulator in a wide energy range from 100 MeV through 629 MeV for user and dedicated low alpha modes. Mitigating the pertubations caused by the undulator to an acceptable level for all user requests, requires each quadrupole in the lattice to be powered individually. To what extend this recently implemented capability allows the restoration of the main properties of the machine optics for various settings of the undulator is presented in this document.  
THPC013 THz Studies at a Dedicated Beamline at the MLS 2933
  • R. Müller, A. Hoehl, A. Serdyukov, G. Ulm
    PTB, Berlin, Germany
  • J. Feikes, M. Ries, G. Wüstefeld
    HZB, Berlin, Germany
  The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute is operating the low-energy electron storage ring Metrology Light Source (MLS) in Berlin-Adlershof in close cooperation with the Helmholtz-Zentrum Berlin. The MLS is designed and prepared for a special machine optics mode (low-alpha operation mode) based on a sextupole and octupole correction scheme, for the production of coherent synchrotron radiation in the THz region*. At the MLS two bending magnet beamlines dedicated to the use of IR and THz synchrotron radiation are in operation: the MLS-IR beamline optimized for the NIR to FIR, and a dedicated THz beamline optimized for the FIR/THz spectral range**. Low-alpha operation optic modes for different ring energies, 250 MeV, 350 MeV, 450 MeV and 630 MeV are available. We compare the THz spectra taken in the different low-alpha modes and discuss the results.
* J. Feikes et al., Phys. Rev. ST Accel. Beams 14, 030705 (2011).
** R. Müller et al., J. Infrared Milli Terahz Waves, in press (2011), DOI: 10.1007/s10762-011-9785-6.
THPC014 Simultaneous Long and Short Electron Bunches in the BESSY II Storage Ring 2936
  • G. Wüstefeld, A. Jankowiak, J. Knobloch, M. Ries
    HZB, Berlin, Germany
  A scheme is discussed, where short and long bunches can be stored simultaneously in the BESSY II storage ring. With recent developments in sc-rf cavity technology it becomes possible, to install high gradient cavities in electron storage rings. With an appropriate choice of these cavities stable fixed points with different rf-voltage gradients are available, leading to different zero current bunch lengths. For BESSY II, we discuss the simultaneously storage of bunches with rms-lengths of 2 ps and 15 ps at high beam intensities. Additionally, in a low alpha optics sub-ps and ps-bunches are possible and a double bucket optics can be set up to store the two types of beams simultaneously on different orbits. Ultra-short and long bunches can be supplied to the users, separated by slightly different orbits.  
THPC010 Recent Developments at the Metrology Light Source 2927
  • J. Feikes, T. Birke, O. Dressler, D.B. Engel, F. Falkenstern, B. Franksen, A. Heugel, H.-G. Hoberg, F. Hoffmann, J. Kuszynski, J. Rahn, M. Ries, P.O. Schmid, T. Schneegans, D. Schüler, G. Wüstefeld
    HZB, Berlin, Germany
  • K.B. Bürkmann-Gehrlein, V. Dürr, H.G. Glass, G. Schindhelm
    BESSY GmbH, Berlin, Germany
  • R. Klein
    PTB, Berlin, Germany
  The Physikalisch-Technische Bundesanstalt (PTB), the German national metrology institute, owns the electron storage ring Metrology Light Source (MLS) which was built and is operated by the Helmholtz-Zentrum Berlin [1, 2]. The MLS has been in regular user operation since April 2008 and supports synchrotron-radiation-based metrology and technological developments in the IR, UV, VUV and EUV spectral range. Here we report on recent progress to develop the MLS into a reliable, flexible and stable user facility.