Time-over-threshold studies in the 2002 Monte Carlo GEANT 3 simulation of the ATLAS Transition Radiation Tracker

We report on the current status of the Time-over-Threshold (ToT) separation power for particle identification in the Atlas simulation using the Transition Radiation Tracker (TRT). The results are compared to similar measurements obtained with the 1999 version of the TRT simulation. The 2002 simulation uses a different model of the TRT electronics shaping circuit which reflects the revised design for electronic chip. The resulting particle identification power obtained using the ToT method is lower than what had been obtained with the previous shaping function.