Dr Marian Ivanov (GSI)
We will present a Particle identification algorithm, as well as a calibration and performance study in the ALICE Time Projection Chamber (TPC) using the dEdx measurement. New calibration algorithms had to be developed, since the simple geometrical corrections were only suitable at 5-10% level. The PID calibration consists of the following parts: gain calibration, energy deposit calibration as a function of angle and position and Bethe-Bloch energy deposit calibration. The gain calibration is done in the space domain (pad-by-pad gain calibration), as well as in the time domain (gain as a function of time, pressure, temperature and gas composition). The energy deposit calibration is done, taking into account the particle dependence on the track topology (inclination angles with respect to the detection layer and particle position). For the Bethe-Bloch energy calibration, five parameters of the Bethe-Bloch formula, which are used for the TPC PID, were fitted for the TPC gas mixture. The studies were performed on the cosmic data, and the comparison with the MonteCarlo simulation showed good results.
|Presentation type (oral | poster)||oral|