Effect of Eddy Currents Induced in the Thermal Shield During the Quench of the Superconducting Coils for the Super-FRS of the FAIR Project

The Superconducting FRagment Separator (Super-FRS) is a two-stage separator to be built next to the site of GSI, Darmstadt, Germany, as part of Facility for Anti-Proton and Ion Research. Its purpose is to create and separate rare isotope beams and to enable the mass measurement also for very short lived nuclei. Overall, the Super-FRS consists of 24 dipole magnets of so-called superferric type, with superconducting coils but the field shaped by magnetic iron. The coil is trapezoidal-shaped configuration, which is wound with NbTi wires of high Cu/Sc ratio and located inside a cryostat equipped with a thermal shield and cooled with liquid helium; but the dipole will have a warm iron yoke with a wide air trim slot. This paper presents the results of the eddy current calculations in the thermal shield induced during the quench of the magnet. The mechanical behavior of the thermal shield under the Lorentz forces generated by the eddy currents will also be presented.