The Central Outer Tracker for Run II at CDF

This paper discusses the design, construction, and installation of the new open-cell drift chamber, the Central Outer Tracker (COT), for Run II operation at the Collider Detector at Fermilab. The COT improves upon the tracking performance of the Run I CTC drift chamber (e.g., increased stereo capability) while at the same time successfully accommodating the smaller bunch crossing and higher luminosity of Run II. The operation and performance of the COT since the Fall, 2000 commissioning run and the beginning of Run II in March, 2001 is presented, including chamber resolution, efficiency, and aging. Additionally, plans are discussed for modifying the COT and associated electronics and data acquisition in order to handle the higher luminosities expected for Run IIb.