Single interaction point operation of CESR

The Cornell Electron Storage Ring is configured to collide beams at a single interaction point. There are seven bunches in each beam and the beams are separated horizontally at each of the thirteen parasitic crossing points. The horizontal displacement is achieved with two symmetrically placed pairs of electrostatic separators. The optical functions are constrained to minimize the long-range beam-beam tune shift and maximize the aperture for the separated beams. In addition, the optics are designed to eliminate differences in damping partition numbers and path lengths for the two beams. The sextupole strengths are distributed so that the tunes of the electrons and positrons are equal.<>