Nonlinear effects induced by closed orbit deformation in SIS18

For the SIS18 operations as booster for the SIS100 it is necessary to maximize its intensity and minimize the beam loss at nonlinear resonances. The understanding of the beam loss mechanisms needs a full experimental and theoretical beam dynamics study in order to quantify each source of the nonlinear errors in the machine. First results of a novel technique to identified the strength and locations of the nonlinear errors are presented here. Compensation of the resonances is an important issue for the improvement of the machine performance. In the framework of the SIS18 upgrade a measurement on resonance beam loss induced by closed orbit (CO) distortion was carried out. CO errors are relevant for feed down effects of multipoles, which generate unwanted resonances [1]. A static tune scan