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Ullrich, J.

Paper Title Page
TUPC055 Operating MCP Detectors at Cryogenic Temperatures 1179
 
  • K.-U. Kuehnel, C. D. Schroeter, J. Ullrich
    MPI-K, Heidelberg
 
  At present, a low energy electrostatic storage ring operating at cryogenic temperatures down to 2 K is being build up at the MPI-K in Heidelberg. Both, beam diagnostics and experiments rely on the use of position sensitive micro-channel plate (MCP) detectors equipped with phosphor screens or delay line anodes. Since little is known about the performance of these detector types in a cryogenic environment a test chamber was built to investigate their properties. A delay line MCP detector was successfully tested at temperatures as low as 25 K. In this contribution the detailed results of theses tests as well as possible applications of the detector are presented.  
TUPC056 A Novel Beam Profile Monitor Based on a Supersonic Gas Jet 1182
 
  • K.-U. Kuehnel, M. Putignano, C. D. Schroeter, J. Ullrich, C. P. Welsch
    MPI-K, Heidelberg
 
  At very low residual gas pressure below 10-12 mbar, as foreseen in future low-energy storage rings currently under development at the MPI-K and FAIR, conventional residual gas beam profile monitors cease to work with reasonable count rates. One possible way to overcome this restriction is the use of a supersonic gas jet as a profile monitor. Such a jet could be shaped as a thin curtain, thus providing a uniform target with a variable target density extended over the whole beam. A possible setup of such a device taking into account vacuum considerations, expected count rates and an envisioned detection scheme are presented in this contribution.  
MOPC137 The Cryogenic Storage Ring Project at Heidelberg 394
 
  • R. von Hahn, K. Blaum, J. R. Crespo López-Urrutia, M. W. Froese, M. Grieser, M. Lange, F. Laux, S. Menk, D. Orlov, R. Repnow, C. D. Schroeter, D. Schwalm, T. Sieber, J. Ullrich, J. Varju, A. Wolf
    MPI-K, Heidelberg
  • H. Quack
    TU Dresden, Dresden
  • M. Rappaport, D. Zajfman
    Weizmann Institute of Science, Physics, Rehovot
  • X. Urbain
    UCL CRC, Louvain-la-Neuve
 
  At the Max-Planck-Institut für Kernphysik in Heidelberg a next generation electrostatic storage ring at cryogenic temperatures is under development. The main perspective of this unique cryogenic storage ring (CSR) is the research on ions, molecules and clusters up to bio molecules in the energy range of 20 keV -300 keV at low temperatures down to 2 Kelvin. The achievement of this low temperature for all material walls seen by the ions in the storage ring not only causes a strong reduction of black body radiation incident onto the stored particles, but also acts as a large cryopump, expected to achieve a vacuum of better than 1·10-15 mbar (corresponding to 1·10-13 mbar room temperature äquivalent). The low temperature and the extreme low vacuum will allow novel experiments to be performed, such as rotational and vibrational state control of molecular ions and their interaction with ultra-low energy electrons and laser radiation. A 20 W at 2 K refrigerator was designed and successfully commissioned. A connection with the fully assembled cryogenic prototype ion trap is under way. In this paper the concept and the status of the cryogenic storage ring will be presented.