TRACKING WITH THE ALEPH TIME PROJECTION CHAMBER

The tracking performance of the ALEPH Time Projection Chamber (TPC) has been studied using the data taken during the LEP running periods in 1989 and 1990. After careful correction of residual distortions and optimization of coordinate reconstruction algorithms a single coordinate resolution of 173-mu-m in azimuthal and 740-mu-m in longitudinal direction is achieved. This results in a momentum resolution for the TPC alone of DELTA-p/p2 = 0.0012 (GeV/c)-1. In combination with the ALEPH Inner Tracking Chamber (ITC) a total momentum resolution of DELTA-p/p2 = 0.0008 (GeV/c)-1, close to the design specifications is reached.