Status of the IUCF electron cooled storage ring

Beam commissioning of a new 2.4 Tm injector synchrotron (CIS) for the IUCF Cooler is complete and Cooler injection development has progressed enough to allow Cooler experiments to resume with up to 1010 stored, cooled, unpolarized protons. The injector synchrotron is designed to fill the Cooler with 1011 polarized protons (deuterons) via bucket-to-bucket longitudinal stacking of 2.5×1010 protons per pulse. CIS is presently delivering 1×1010 unpolarized protons/pulse at 201.5 MeV to the Cooler injection system at 0.8 Hz. Injection efficiency into the Cooler stored orbit is 50% and accumulations to 2.5 mA in 5 s was demonstrated via both cooled coasting beam accumulation and longitudinal stacking. Installation of a 1 mA polarized H− source on the CIS injection beam line began on February 4 and is nearly complete. Delivery of polarized protons to the Cooler from CIS is scheduled to begin in June 1999. This contribution will report on the beam capabilities of the new CIS injector and the resulting Cooler performance enhancements.