CESR Phase III interaction region

The goal of the third phase of the CESR/CLEO upgrade is to take the CESR luminosity as far as one can go with a single-ring collider. In the present configuration of CESR (Phase II) trains of closely spaced bunches collide at a small horizontal crossing angle (/spl theta//sub c//spl sime//spl plusmn/2 mrad). The Phase III upgrade program relies on increasing the colliding beam current from the present 0.5A to 1A by exploiting bunch-train collisions to the fullest extent possible. This work discusses beam optics, the interaction region magnets, detector backgrounds and the vacuum system.