THE SUPERCONDUCTING INJECTOR LINAC FOR THE COOLER- SYNCHROTRON COSY AT FZ-JUELICH

The Institut für Kernphysik of the Forschungszentrum Jülich (FZJ) has started with the design and development of a superconducting injector linac for the cooler-synchrotron COSY to replace the cyclotron JULIC. The project aims to increase the intensity of polarized proton and deuteron beams in COSY typically by a factor of ten compared to what can be provided at present. The improved capabilities will enable us to fully exploit the unique experimental opportunities of the facility, and thus significantly strengthen and extend its scientific viability. The new injector makes use of a super-conducting linac, together with advanced ion sources and two inter-change-able RF-Quadrupole (RFQ) pre-accelerators for H- and D-ions, respectively. The linac design is based on a super-conducting half-wave resonator (HWR) structure with in-dependently phased cavities and separated functions to deliver both polarized and unpolarized pulsed H- and D-beams at a kinetic energy between 50 and 60MeV for charge-exchange injection into COSY. The beam current will be 2mA (peak) in pulses lasting up to 0.5ms at a repetition rate of 2Hz. The planned layout of the injector is presented and its design specifications are discussed, together with the present status of the project.