Disruption Effects from the Collision of Quasi-Flat Beams*

Absiract The disruption effects from the collision of round beams and flat beams in linear colliders have been studied in the past, and has by now been well understood. In practice, however, in the current SLC running condition and in several designs of the next generation linear colliders, the quasi-flat beam geometries are expected. Namely, the beam aspect ratio R z us/or > 1, but not infinitely large. In this regime the disruption effects in both z and y dimensions should be carefully included in order to prop erly describe the beam-beam interaction phenomena. In this paper we investigate two major disruption effects for the the quasi-flat beam regime: The luminosity enhancement factor and the effective beamstrahlung. Computer simulations are employed and simple scaling laws are deduced. -&-