The main components of the ALICE TPC were tested with cosmic rays and beam particles. An Inner Readout Chamber was fully equipped with front end electronics including the DAQ chain, and operated in combination with a prototype field cage. The noise performance, baseline restoration, and characteristics of the ion tail for different gas mixtures were studied in detail. Furthermore, the spatial resolution for tracks and the particle identification performance over a momentum range from 1– 7 GeV / c were measured. The measured specific energy loss was compared with predictions from a photo absorption ionization model.
