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Müller, A.-S.

Paper Title Page
MOPC001 Final Results from the Novel Multiturn Extraction Studies at CERN Proton Synchrotron 117
 
  • M. Giovannozzi, R. Cappi, S.S. Gilardoni, M. Martini, E. Métral, R.R. Steerenberg
    CERN, Geneva
  • A.-S. Müller
    FZK, Karlsruhe
 
  Recently a novel approach to perform multi-turn extraction was proposed based on beam splitting in the transverse phase space by means of trapping inside stable islands. An experimental campaign was launched since the year 2002 to assess the feasibility of such an extraction scheme at the CERN Proton Synchrotron. During the year 2004 run, a high-intensity single-bunch beam was successfully split and the generated beamlets separated without any measurable losses. The latest experimental results are presented and discussed in details in this paper. These achievements represent a substantial step forward with respect to what achieved in previous years, as only a low-intensity bunch could be split without losses. Furthermore, this opens the possibility of using such a technique for routine operation with the high-intensity proton beams required for the planned CERN Neutrino to Gran Sasso Project.  
MPPP001 A Vertical Multi-Bunch Feedback System for ANKA 761
 
  • P. Wesolowski, I. Birkel, E. Huttel, A.-S. Müller, M. Pont, F. Pérez
    FZK, Karlsruhe
 
  ANKA is a synchrotron light source with a top energy of 2.5 GeV. The maximum electron current at ANKA is presently limited by multi-bunch instabilities to 200 mA. In order to overcome this barrier a transverse analog multi-bunch feedback system is presently being commissioned. A BPM is used for beam detection. The vertical position signal passes a notch filter, is amplified, and subsequently fed to a vertical beam kicker. The present paper shows the layout of ANKA feedback system and discusses the first results of its operation.  
RPAE037 Operation with a Low Emittance Optics at ANKA 2467
 
  • E. Huttel, A. Ben Kalefa, I. Birkel, A.-S. Müller, P. Wesolowski
    FZK, Karlsruhe
  • M. Giovannozzi
    CERN, Geneva
  • M. Pont, F. Pérez
    CELLS, Bellaterra (Cerdanyola del Vallès)
 
  ANKA is a synchrotron light source operating in an energy range from 0.5 to 2.5 GeV. The electron storage ring at ANKA is designed as a variation of an eightfold Double Bend Achromat structure. Since its commissioning the facility has been operated with zero dispersion in the long straight sections resulting in an emittance of about 100 nmrad. Since mid 2004 ANKA is operated with dispersion distributed over the complete ring thus reducing the emittance to 40 nmrad. In the course of the re-design of the storage ring optics a compensation of higher order field components leads to a visibly increased momentum acceptance. Optics calculations and measurements as well as operational experience will be discussed.  
RPAE038 Far Infrared Coherent Synchrotron Edge Radiation at ANKA 2518
 
  • A.-S. Müller, I. Birkel, B. Gasharova, E. Huttel, R. Kubat, Y.-L. Mathis, W. Mexner, D.A. Moss, F. Pérez, R. Rossmanith, P. Wesolowski, M. Wuensch
    FZK, Karlsruhe
  • C. J. Hirschmugl
    UWM, Milwaukee, Wisconsin
  • M. Pont
    CELLS, Bellaterra (Cerdanyola del Vallès)
 
  A synchrotron radiation source emits coherent infrared (IR) radiation when the electron bunch length is comparable to the wavelength of the emitted radiation. To generate coherent radiation in the far IR (THz) region, a "low alpha mode" has been devised at the ANKA storage ring operating at 1.3 GeV. The corresponding lattice has a significantly reduced momentum compaction factor. The spectral dependence of the emitted radiation is recorded at the ANKA-IR beamline, where the synchrotron light is produced in the fringe field of a bending magnet. This edge radiation has the advantage of being more collimated than constant field radiation. This allows the observation of frequencies down to 1 cm-1 through a modest vertical aperture, which would not be possible with classical constant field emission due to the increasing beam divergence with decreasing frequency. The onset of coherent emission is found at a synchrotron frequency of about 10 kHz. At 5 kHz, an intensity enhancement of up to 5 orders of magnitude, with respect to the incoherent emission, is observed in the spectral range between 1 and 65 cm-1.  
RPAE039 Operation of the ANKA Synchrotron Light Source with Superconductive Undulators 2559
 
  • R. Rossmanith, MH. Hagelstein, B.K. Kostka, A.-S. Müller, D. Wollmann
    FZK, Karlsruhe
  • T. Baumbach, A. Bernhard
    FZ Karlsruhe, Karlsruhe
  • E. Steffens
    Erlangen University, Erlangen
  • M. Weisser
    University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
 
  The synchrotron light source ANKA (2.5 GeV, 200 mA) is a versatile multi-purpose storage ring with beam lines for coherent IR and THz radiation (IR-laser), LIGA applications and high brilliance X-rays. It is now plannned to install in addition several superconductive undulators for a wide range of applications: fast tunable X-rays for material research, imaging applications and an undulator with variable polarization direction for a dichroism beamline. This development of ANKA is the result of successful research on superconductive undulators which surpass the performance of permanent undulators by far (collaboration between ANKA, the University of Karlsruhe and the University of Erlangen-Nürnberg). The basic layout of the undulators and the required changes to a storage ring to accommodate the superconductive undulators is described in this paper.