The large TPC prototype for an ILC detector

A Time Projection Chamber (TPC) is a candidate for the central tracker of the International Linear Collider (ILC) detectors because of its very good performance in past collider experiments. In order to obtain one order-of-magnitude improvement in momentum resolution and the highest possible track-recognition efficiency, the Linear Collider TPC (LCTPC) groups [1] are pursuing R&D to find the best state-of-the-art technology for the TPC. A Large Prototype (LP) of a TPC is being constructed, which will have a diameter of about 750 mm and a length of about 600 mm, which allows to measure tracks with up to 125 space points with pad readout. This prototype will fit into a superconducting magnet, installed in a DESY test beam area.