R and D for a SiW Electromagnetic Calorimeter for a Future Linear Collider

This article presents an overview on the status and perspectives of a highly granular silicon tungsten electromagnetic calorimeter (SiW Ecal) conceived for the operation at a future linear electron-positron collider. Prototypes for this kind of calorimeters are developed within the R and D program of the international collaboration CALICE. This article reports on results on the 'pure' calorimetric performance of a first physics prototype with an energy resolution of about 17%/√E and an angular resolution of about 100 mrad. Beyond that, emphasis is put on the merits of the high granularity which is indispensable for the achievement of the envisaged physics goals of a linear collider. This high granularity permits the application of image processing algorithms for particle separation as well as it reveals a more detailed view into hadronic cascades than was possible hitherto.