Coherency of the long range beam-beam interaction in CESR

The main limitation to the maximum number of bunches the ring can accommodate is due to the long range beam-beam interaction that occurs when the bunches pass by each other in the arcs. We consider a single bunch current limited by the long range beam-beam interaction and the addition of more bunches. A number of machine studies described quantitatively address the question of coherency and bunch spacing. This work on coherency follows earlier long range beam-beam studies where we evaluated various phenomenological models and found that the limiting pretzel increases roughly as the square root of the bunch current.