[Zurück]

P. Haiden, J. Erhart, H. Fillunger, M. Horvath, G. Konrad, M. Moser, X. Wang, C. Ziener, H. Abele et al.:
"Design of the Magnetic Shielding for PERC";
Poster: DPG spring meeting 2013 (Hadronic and Nuclear Physics), Dresden; 04.03.2013 - 08.03.2013.

The new facility PERC is a novel source of neutron decay products,
currently under development by an international collaboration. Its
main component is a more than 11m long superconducting magnet
system (up to 6 T). In order not to disturb other experiments in the
vicinity of PERC, we have designed a magnetic shielding. The finite
element method (COMSOL Multiphysics) has been used to determine
the most suited geometry for the shielding. The following considerations
were taken into account: the magnetic stray field is suppressed to
the cardiac pacemaker level (0.5mT at less than 3.0 m), the internal
magnetic field and its homogeneity (up to 10−4) are not disturbed, the
additional forces onto the coils are not destructive, and the shielding deals with the limited space conditions. For experimental reasons, the magnet geometry is non-axisymmetric and therefore has to be simulated in 3D. To reduce the computing time and simultaneously increase the numerical accuracy, we simulated only one half of the geometry, taking advantage of the symmetry both of magnet and shielding. However, to study the influence of the shielding on the particle trajectories we had to simulate the full geometry. The magnetic and the mechanical design of the magnetic shielding for PERC will be presented.