SIS18 Status Report

In the frame of a dedicated machine development run with N-ions, operation with high space charge tune shift was demonstrated. About 10 11 N-ions could be injected leading to an incoherent tune shift of up to dQv=-0.2. By means of the new residual gas profile monitor, fast emittance blow-up was observed during the transition from the high current working point to the working point required for slow extrac- tion. Since the incoherent tune shift is getting more often an origin for beam losses at high current operation, the reso- nance diagram was subject of a number of machine experi- ments. A scanning method to determine strength and loca- tion of the resonances was developed. Several scans of the tune diagram around the standard working point have been performed (1).