• E. Huttel, I. Birkel, A.-S. Müller, N.J. Smale, K.G. Sonnad, P. Wesolowski
  FZK, Karlsruhe

The ANKA storage ring is filled at 0.5 GeV and then ramped to 2.5 GeV for regular user operation. A full-energy injection of the ANKA storage ring would have several advantages. The damping at a beam energy of 2.5 GeV is stronger, which will more efficiently fight instabilities during the injection, therefore allowing higher beam currents. With constant magnet settings, the orbit stability would improve significantly. The injection time would be reduced and topping- up operation would become possible. As a consequence, the optical elements of the user beamlines would see a constant power as a function of time which further enhances the overall stability. In this paper, a design for a full energy injector is proposed. The injector will be located inside the storage ring tunnel, similar to the SLS and ALBA design. The focusing is mainly provided by combined function magnets. The full energy injector has a design emittance of 40 nmrad and a circumference of 94.8 m. A modification of the existing storage ring is foreseen to house the necessary more powerful injection elements.

• A.-S. Müller, I. Birkel, E. Huttel, Y.-L. Mathis, N.J. Smale
  FZK, Eggenstein
• E. Bründermann
  Ruhr-Universität Bochum, Bochum
• T. Bückle, M. Fitterer, S. Hillenbrand, N. Hiller, A. Hofmann, V. Judin, M. Klein, S. Marsching, K.G. Sonnad
  KIT, Karlsruhe
• J. Feikes, M.V. Hartrott
  HZB, Berlin
• H.W. Huebers, A. Semenov
  DLR, Berlin
• R. Klein, R. Müller, G. Ulm
  PTB, Berlin
• G. Wüstefeld
  BESSY GmbH, Berlin

Funding: This work has partly been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320.

In synchrotron radiation sources coherent radiation is emitted when the bunch length is comparable to or shorter than the wavelength of the emitted radiation. A detector system based on a superconducting NbN ultra-fast bolometer with an intrinsic response time of about 100 ps jointly developed by the University of Karlsruhe (Institute of micro- and nanoelectronic systems) and German Aerospace Center (Berlin) was used to resolve the radiation emitted from single bunches. This paper reports the observations made during measurements at the MLS and ANKA storage rings.

• K.G. Sonnad, I. Birkel, S. Casalbuoni, E. Huttel, D. Saez de Jauregui, N.J. Smale
  FZK, Eggenstein
• F. Caspers
  CERN, Geneva
• A.-S. Müller, K.G. Sonnad
  KIT, Karlsruhe
• R. Weigel
  Max-Planck Institute for Metal Research, Stuttgart

Funding: This work has partly been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320.

A superconducting undulator is installed in the ANKA electron storage ring. Electron clouds could potentially contribute to the heat load of this device. A microwave transmission type electron cloud diagnostic has been installed for the undulator section of the ANKA machine. We present the system layout with particular emphasis on the electron machine aspects. Hardware transfer function results and e-cloud data for different machine settings are discussed. Special care has been taken for front end filter design both on the microwave injection and pick-up side.

• K.G. Sonnad, I. Birkel, S. Casalbuoni, E. Huttel, N.J. Smale
  FZK, Eggenstein
• F. Caspers
  CERN, Geneva
• N. Hiller, A.-S. Müller, K.G. Sonnad
  KIT, Karlsruhe
• R. Weigel
  Max-Planck Institute for Metal Research, Stuttgart

Funding: This work has partly been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320

The status of longitudinal and transverse Schottky observation systems for the synchrotron light source ANKA is presented. ANKA regularly operates in a dedicated low alpha mode with short bunches for the generation of coherent THz radiation. The Schottky measurement results are shown and compared with theoretical predictions for the regular as well as the different stages of the low alpha mode of operation. Special care had to be taken to control and mitigate the impact from strong coherent lines of the short bunches on the signal processing chain. The system setup is shown, expected and unexpected observations as well as applications are discussed.

• M. Klein, T. Bückle, M. Fitterer, A. Hofmann, A.-S. Müller, K.G. Sonnad
  KIT, Karlsruhe
• I. Birkel, E. Huttel, Y.-L. Mathis
  FZK, Karlsruhe

Funding: This work has been supported by the Initiative and Networking Fund of the Helmholtz Association under contract number VH-NG-320.

In synchrotron light sources, coherent synchrotron radiation (CSR) is emitted at wavelengths comparable to and longer than the bunch length. One effect of the CSR wake field is the distortion of the bunch distribution, which increases with higher currents. In the theoretical calculations, a threshold exists beyond which the solutions begin to diverge. On the other hand, the CSR wake can also excite a micorbunching instability which prevents stable emission of CSR for high currents and leads to highly intense bursts of radiation. In this paper the development of the calculated bunch shapes and the corresponding moments of the current distribution for varying bunch currents are studied. It can be shown that the numerical threshold beyond which the solutions diverge, does not coincide with the observed bursting-stable-threshold at the ANKA storage ring, which agrees well with theory.