A transition radiation detector which features accurate tracking and dE/dx particle identification

The results of a test run involving a transition radiation detector (TRD) that can distinguish electrons from pions with momenta greater than 0.7 GeV/c and simultaneously track particles passing through the detector are described. The particle identification is accomplished by a combination of the detection of transition radiation from the electron and the difference in electron and pion energy (dE/dx) in the detector. The dE/dx particle separation is most efficient below 2 GeV/c, while particle identification utilizing transition radiation is effective above 1.5 GeV/c. Combined, the electron-pion separation is better than 5*10/sup 2/. The single-wire, track-position resolution for the TRD is approximately 230 mu m.< >