Performance and aging of the BaBar Drift Chamber

The BaBar Drift Chamber is a cylindrical, small-cell drift chamber installed at the PEP-II B-Factory. It has been operating since May 1999, integrating nearly 175 fb - 1 luminosity in e + e - collisions at s ∼ 10.6 GeV . The chamber has accumulated a dose of 12.8 mC/cm, resulting in a drop in gain of approximately 6.4%. The drift chamber has met most of its design goals (position, momentum, and dE/dx resolution) while maintaining extremely high efficiency for charged track reconstruction. The chamberʹs operational history and performance will be presented, along with a discussion of the effects of aging and extrapolations for future performance, through 2008.