Crossing geometry and the location of colliding beam areas

Initial collider operation is anticipated in two long straight sections, with possible operation of a third region at a later date. The choice between regions B0--C0 vs B0--E0 must await a more complete design of the Tevatron machine and also requires detailed calculations of the machine parameters for each of these choices. The transposed schemes for bringing about collisions are more flexible and better adapted to colliding operation than the kissing geometry. Engineering studies indicate that the effort required for transposition is relatively small. The kissing geometry is less attractive and should be considered as a fall-back position, or for eventual use in a third area