Description of a High Rate Luminosity Monitor Installed at CESR

In response to a need for a fast, direct measure of luminosity for the purpose of machine optimization, a high rate luminosity monitor has been constructed for CESR. The interaction regions at CESR employ a standard minibeta lattice in which the inner quadrupoles are vertically focussing. Bhabha scattered particles are horizontally defocussed upon traversing these quadrupoles. A beam pipe constricted in the horizontal plane was constructed to detect these high event rate particles. This paper is a description of the luminosity, background, and accidental rates observed with various detector schemes. These results are compared with calculations. Stability and beam steering sensitivies are also explored.