A Doublet of 3 in. cylindrical Silicon Drift Detectors in the CERES Experiment

We report on the performance of a doublet of 3 in. cylindrical silicon drift detectors installed as an upgrade of the CERES/NA45 electron pair spectrometer for the Pb-beam at the CERN SPS. The silicon detectors provide external particle tracking and background rejection of conversions and close Dalitz pairs. Results on vertex reconstruction and rejection from a Pb test-run in 1994 are presented