Study on electron/pion discrimination with the CBM transition radiation detector

In the CBM experiment at FAIR, a transition radiation detector (TRD) is foreseen for tracking and electron/pion discrimination. Up to twelve detector layers are considered, each with a thin gas volume in order to have sufficiently fast readout for the intended high collision rates. This however compromises the TR-photon absorption efficiency, which is essential for electron identification. A combined study of the electron/pion discrimination dependence on the detector thickness and on two methods of combining the signals of the individual layers is presented. The influence of the radiator performance is discussed. For a single detector, the employed simulations are compared to prototype measurements.