Particle identification using dEdx in the mark II detector at the SLC

Abstract The central drift chamber in the Mark II detector at the SLAC linear collider has been instrumented with 100 MHz flash-ADCs. Pulse digitization provides particle identification through the measurement of average ionization loss in the chamber. We present the results of a study of system performance and outline the systematic corrections that optimize resolution. The data used are from a short test run at PEP with one third of the FADCs installed, and an extensive cosmic ray sample with the fully instrumented chamber.