Particle Identification Using De/dx in the Mark Ii Detector at the Slc*

The central drift chamber in the Mark II detector at the SLAC Linear Collider has been instrumented with loo-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. Presented at the 5th International Wire Chamber Conference: Recent Trends and Alternative Techniques, Vienna, Austria, February 13-17, 1989 * Work supported by the Department of Energy, contract DE-AC03-76SF00515. t Present Address: University of Colorado, Boulder, Colorado 80309