Radiation damage studies and lifetime estimates for the CDFII silicon detector

The CDFII silicon detector system operates in a severe radiation environment as it measures the products of high energy proton-antiproton interactions provided by the Tevatron Run II accelerator. This article describes the manifestation of radiation damage to the detector's silicon sensors in two ways: the evolution of sensor depletion voltages toward a maximum value, and the degradation of the signal-to-noise ratios for charge clusters read out by the detector. In both cases we use data collected through 1.8fb-1 of integrated luminosity to determine the detector's ability to perform for the lifetime of the Tevatron Run II, expected to be 5-8fb-1 of integrated luminosity.