Beam test of the SLD silicon-tungsten luminosity monitor

A set of calorimeters using silicon diode sampling has been constructed to provide the small angle electromagnetic calorimetry for SLD (Stanford Linear Collider Large Detector) at SLAC (Stanford Linear Accelerator Center). The luminosity monitor and small angle tagger (LMSAT) and the medium angle silicon calorimeter (MASC) measure the direction and energy of electrons and photons in the region of 23-190 mrd from the SLD beam axis. The calorimeter uses nearly two square meters of silicon diodes segmented into cells approximately one square centimeter in area. One LMSAT module has been tested with electrons at the Brookhaven National Laboratory. The stack consists of 23 layers of silicon diodes separated by about one-radiation-length (3.5-mm) layers of tungsten alloy. The results of this beam test, including energy and spatial resolution, are presented. >