Status and perspectives of the cyclotron JULIC as COSY injector

Since January 1996, the cyclotron JULIC operates more than 7500 hours per year as injector of H- or D- beams for the cooler synchrotron COSY at the IKP of the Forschungszentrum Jülich. Usually about 8 žA of unpolarized or 1 žA of polarized H- ions are delivered at 45 MeV for charge-exchange injection into COSY; higher beam intensities would be required especially for polarized beams to fill COSY to its space-charge limit. Also unpolarized D- ions at 75 MeV were delivered with good results, although the septum-deflector insulators give problems at higher voltage. The demand for deuterons at COSY is growing, however, and the first polarized D- beam is already scheduled for tests. This report sums up the characteristics of the cyclotron in its present mode of operation and describes the quest for higher beam intensities as well as for providing D- beams reliably. The results are presented and discussed in terms of JULIC’s future suitability as COSY injector.