A GEM-TPC prototype with low-noise highly integrated front-end electronics for linear collider studies

Connected to the linear collider project, studies on the readout of time projection chambers (TPCs) based on the gas electron multiplier (GEM) are ongoing. Higher granularity and intrinsically suppressed ion feedback are the major advantages of this technology. After a short discussion of these issues, we present the design of a small and very flexible TPC prototype, whose cylindrical drift volume can be equipped with endcaps of different gas detector types. An endcap with multi-GEM readout is currently set up and successfully operated with a low-noise highly integrated front-end electronics. We discuss results of measurements with this system in high intensity particle beams at CERN, where 99.3 ± 0.2 % single-pad-row efficiency could be achieved at an effective gain of 2.5 × 10³ only, and spatial resolutions down to 63 ± 3 μm could be demonstrated. Finally, these results are extrapolated to the high magnetic field in a linear collider TPC.