Study of a TPC prototype with GEM readout

The TPC read out by GEM detector has many advantages over the traditional ones read out by MWPC (Multi- Wire Proportional Counter). It is a very promising candidate for the central tracking system of International Linear Collider (ILC). In our lab, a GEM-TPC prototype was designed and constructed successfully; the performance of the prototype has been studied; some of the test result using cosmic-ray is presented in this paper.