Transient 3D Finite Element Simulations of the Field Quality in the Aperture of the SIS-100 Dipole Magnet

Abstract

The dipole magnets for the new heavy-ion synchrotron SIS-100, planned within the Facility for Anti-Proton and Ion Research (FAIR) at GSI, Darmstadt, Germany, have to be optimized under certain design requirements. At the intended high beam intensities, the field quality in the aperture is crucial. The geometry of the window-frame magnet featuring superconductive coils was already optimized with respect to the field quality in terms of higher-order multipoles using static 2D and 3D Finite Element (FE) simulations. During fast ramping up to 2 T, however, additional perturbations arise due to local saturation and due to eddy currents in both the yoke and the metallic beam pipe. These have already been investigated using transient 2D FE simulations. In order to further refine these results, a transient nonlinear 3D FE model, capturing the eddy-current effects at the end plates is used. The results are compared to those obtained by static simulations.

Magnetodynamic Finite-Element Simulation of Accelerator Magnets

“…The emphasis is here put on computational aspects. The simulation has been carried out for determining the eddy-current loss per cycle in the SIS-100 magnet [52,[69][70][71], which has been designed as the main dipole for the SIS-100 synchrotron of the Facility for Antiproton and Ion Research (FAIR) [72], which is currently under construction at the Helmholtzzentrum fÃijr Schwerionenforschung (GSI, Facility for Heavy Ion Research) [73] in Darmstadt, Germany. The SIS-100 magnet has a nominal aperture dipole field of 2 T. The magnet is ramped at a rate of 4 T/s (Fig.…”