The new silicon tracker layout (V4) is presented. The system aspects of the
construction are discussed together with the expected tracking performance
. Because of the high radiation environment in which the detectors will ope
rate, particular care has been devoted to the study of the characteristics
of heavily irradiated detectors.
This includes studies on performance (charge collection, cluster size, reso
lution, efficiency) as a function of the bias voltage, integrated fluence,
incidence angle and temperature. (C) 1998 Elsevier Science B.V. All rights