Development of a GEM based TPC Readout for ILD

Abstract: For the International Large Detector (ILD), foreseen to be built at the International Linear Collider (ILC), a Time Projection Chamber (TPC) is intended to be used as the main tracking detector. The amplification will be provided by Micro Pattern Gaseous Detectors (MPGDs). One option is the use of Gas Electron Multipliers (GEM) in combination with a segmented pad readout plane. The TPC group at DESY developed a modular system implementing a triple GEM stack mounted on thin ceramic grids. This material choice allows for high mechanical rigidity of the support structure at a reduced amount of material and dead area compared to commonly used GRP frames. This contribution gives an overview of the current status of this system. This includes a discussion of points we wanted to improve over the last generation of modules and what was implemented in the newest version. Also improvements in the production process of the modules, which ensure a consistent quality and present a step towards possible batch production.