A tera-pixel calorimeter for the ILC

To extract the physics required at the International Linear Collider, the detectors will need a jet energy resolution of 30%/radicE (GeV). The most promising approach to reach that goal is the use of particle flow algorithms. Particle flow algorithms measure jet energies by combining both tracking and calorimeter information. This requires the use of highly granular calorimeter systems. For the electromagnetic calorimeter (ECAL) the choice is to use silicon-tungsten sampling calorimeters with a highly granular readout. We propose to use Monolithic Active Pixel Sensors (MAPS) as both sensor and readout for such a calorimeter. This novel design would have an extremely fine granularity of 50 x 50 mum² with binary readout. With a total area of 2000 m² of silicon this leads to a "Tera-Pixel" ECAL. An overview of the MAPS detector concept will be given along with the potential advantages of this design. For the optimization of the design detailed sensor simulations have been used. A first prototype sensor using MAPS has been produced and we show first results obtained with this sensor. We also address system level issues like the required DAQ bandwidth and the power consumption.