Author: Neubert, R.
Paper Title Page
MOPG001 Field Attenuation of the Magnetic Shield for a Cryogenic Current Comparator 17
 
  • F. Kurian, P. Hülsmann, P. Kowina, D.A. Liakin, H. Reeg, M. Schwickert
    GSI, Darmstadt, Germany
  • R. Geithner, R. Neubert
    FSU Jena, Jena, Germany
  • W. Vodel
    HIJ, Jena, Germany
 
  Funding: Work supported by EU, DITANET, Project No. ITN-2008-215080
The upcoming FAIR facility requires measurements of very low ion currents during slow extraction from the synchrotron SIS100. A Cryogenic Current Comparator (CCC), with its capability to measure absolute ion beam currents non-destructively down to nA range, is foreseen to be installed in various locations of the high energy beam transport section of FAIR. The current resolution of the CCC is only limited by the system noise, mainly originating from the environmental electromagnetic fields and mechanical vibrations. A meander-shaped superconducting shield geometry covering the pick-up coil efficiently suppresses disturbing non-azimuthal field components. The attenuation of external magnetic field components by the shield in different field directions is studied for various geometrical and material parameters by means of an FEM simulation. The simulation results are compared with attenuation factors obtained by experiments.