R&D Ongoing at DESY for a GEM based TPC at the ILC: Resolution Studies; Techniques and Results

A large volume Time Projection Chamber (TPC) has been proposed as the main tracking device for experiments at the International Linear Collider (ILC). Gas Electron Multipliers (GEMs) are being studied as a gas amplification system of TPCs. Recent results from R&D activities with GEM-TPC prototypes ongoing at DESY will be presented. The main focus will be on reconstruction methods and techniques and the spatial resolution that can be achieved.