New scheme for the design and operation of proton--proton storage accelerators

A new system is presented for storage accelerating rings which allows many options for operation. During injection, acceleration, and collision, the beams are maintained in the form of azimuthally long bunches. Current is built up in a low-energy, small circumference accumulator ring. Injection into the storage accelerators is carried out with the bunches phased so that they do not collide. The rf buckets can be matched to the incoming long bunches with only a small dilution. Operation of the storage rings consists of: (1) accelerating the formed bunches to any desired energy; and (2) bringing the bunches into collision by relative phasing of the rf in the two rings. This system provides considerable simplification in the design and operation of high energy p-p facilities. For example, it reduces the beam stacking time, relaxes the impedance tolerances relating to longitudinal stability, reduces the aperture utilization, and avoids radiation background problems associated with beam manipulations. A prototype design is considered, using as a basis the parameters of the ISABELLE facility. Performance characteristics and operational procedures are presented. The many advantages related to the machine and experimental aspects are discussed. In particular, cycling the energy during collisions is an interesting option. Lastly, the significance of extending such a facility to higher energy p-p collisions is outlined