SIS100 Dipole Magnet Optimization and Local Toroidal Multipoles

Abstract

SIS100 is the world's second fast ramped synchrotron using superconducting magnets. The foreseen high current operation requires a sound understanding of the field homogeneity next to a field parametrization which allows investigating if the existing inhomogeneity introduces transverse oscillations on the particle beam. The SIS100 dipole magnets are curved so local toroidal multipoles were developed as these follow the orbit of the ion beam. The end of the magnet creates the main field deterioration due to the coil end shape which has to be compensated by a 3D end shim. In this paper we present the Local Toroidal Multipoles next to formulae to derive these from rotating coil probe measurements. Further we outline the possible geometrical options for meeting the field quality target.