Micromegas for imaging calorimetry

Gaseous detectors have been used in sampling calorimeters for several years and still remain an attractive option for future collider experiments. The use of Micromegas chambers as active elements of a hadronic calorimeter was proposed a few years ago and stirred up exciting developments of this technology. Basic building blocks of large size chambers acting as signal generating and processing units have been designed and fabricated. They were used to construct two chambers of 1 m size which after test in muon and pion beams, showed excellent performance. The most important results are presented followed by a discussion of the prospects towards realistic calorimeter modules at a future collider experiment.