Longevity studies in the CDF II silicon detector

The CDF Run II silicon detector is the largest operating detector of its kind in High Energy Physics, collecting pp¿ collision data at the Fermilab Tevatron since 2001. It provides precision tracking and vertexing which played a critical role in the B_s mixing discovery and is essential to the ongoing Higgs Boson search and many other physics analyses carried out at CDF. Due to the prolonged Tevatron Run II program the detector faces unforeseen challenges while operating well beyond its design parameters. Of particular concern is the radiation aging of the silicon sensors which are expected to acquire ~10 fb^-1 data, far above their design integrated luminosity of 2-3 fb^-1. In this paper we discuss the impact of radiation damage to the sensors, their effect on the physics performance and expectations for future operations of the two inner layers, which have already inverted.