Egs 4 Calculations for a Pep - Ii Luminositymonitor ?

The Asymmetric B-Factory currently being built at SLAC consists of a 9 GeV electron storage ring and a 3 GeV positron storage ring, known as PEP-II, and a large detector called BaBar. Because the commissioning of PEP-II starts approximately one year ahead of the installation of BaBar, it is desirable to have a dedicated system in place beforehand for measuring and optimizing the luminosity of the colliding beams. Accordingly, the EGS4 Code System has been used in the design of a quartzglass Cherenkov hodoscope that monitors high-energy showers, initiated by photons emanating from radiative-Bhabha interactions at the Interaction Point located 8.5 meters upbeam. In this paper we present the results of a series of EGS4 calculations to determine the spatial resolution of such a detector, as well as to determine if there will be any serious limitations caused by radiation damage. ? Submitted for presentation at the First International Workshop on EGS4 to be held at KEK, Tsukuba, Japan (26-29 August 1997). y Work supported in part by the Department of Energy contract DE-AC03-76SF00515