Author: Kraemer, A.     [Krämer, A.]
Paper Title Page
Challenges of the FAIR Vacuum System  
  • A. Krämer, M.C. Bellachioma, M. Bevcic, H. Kollmus, J. Kurdal, H. Reich-Sprenger, M. Wengenroth, St. Wilfert
    GSI, Darmstadt, Germany
  The FAIR accelerator complex consists of about 8km of vacuum system (6km beam lines and 2km of isolation vacuum for the superconducting magnets), where the vacuum requirements are different for almost all machines. While in the fast ramped SIS100 one has to deal with cryogenic and bakeable at room temperature operated sections with static vacuum pressure in the lower 10-12mbar regime, the 2.5km of high energy beam transfer system have moderate vacuum requirements of 10-8mbar. The NESR will be fully bakeable and has a design vacuum in the lower 10-12mbar regime, while the HESR, RESR and CR can tolerate higher pressure of 10-10mbar to 10-9mbar. In the Super-FRS one has beside the moderate vacuum of 10-6mbar to 10-8mbar to cope with a high radiation area close to the target. The vacuum challenges to achieve the required vacuum for all the machines will be described in this presentation.  
slides icon Slides TUOAC01 [3.663 MB]  
WEPPD011 Study of the Pressure Profile Inside the NEG Coated Chambers of the SIS 18 2519
  • M.C. Bellachioma, H. Kollmus, A. Krämer, J. Kurdal, H. Reich-Sprenger, L. Urban, M. Wengenroth
    GSI, Darmstadt, Germany
  In the context of the technical developments for the construction of FAIR at GSI, an intensive programme for the vacuum upgrade of the existing SIS 18 was started in 2005, with the aim to improve the beam lifetime and intensity. To reach these purposes also the installation of NEG coated dipole and quadrupole chambers is foreseen. During the upgrade shutdowns performed between 2006 and 2009 the vacuum chambers of approximately 65% of the SIS18 circumference were replaced by NEG coated pipes. To evaluate in detail the pressure profile inside the coated chambers mounted into the accelerator a dedicated experimental set-up, which reproduces a vacuum environment similar to the one of the SIS 18, was built. Using three gauges, mounted in different positions of a coated chamber, it was possible to measure the pressure in the range of 10-12 mbar inside the activated NEG pipe and 10-11 mbar outside the pipe at the pumping posts. Additionally, a modelling of a SIS18 vacuum sector was realised and the pressure variation values obtained by a Monte-Carlo simulation were compared with those measured. In this paper the experimental results and the vacuum simulations are described and discussed.