Development of a GEM-TPC for high rate applications

The concept of a Time Projection Chamber (TPC) has to be further developed to be suitable for high rate experiments. The application of a TPC at high interaction rates with overlapping events in a single drift frame requires a continuous readout. Gas Electron Multipliers (GEM) combine the requirements of an excellent spatial resolution and particle identification by measurements of specific energy loss with an intrinsic suppression of ions. These key features of a GEM allow a TPC to maintain its excellence performance even in an ungated continuous mode. A large GEM TPC prototype with an outer diameter of 30.8 cm, an inner diameter of 10.4 cm and a drift length of 72.8 cm and 10.000 readout channels has been built and tested within the low rate FOPI experiment at the GSI. The TPC detector, preliminary performance studies of the GEM TPC prototype within FOPI as well as an outlook for a potential application of this concept are presented.