Construction and test of a 1×1 m2 Micromegas chamber for sampling hadron calorimetry at future lepton colliders

Sampling calorimeters can be finely segmented and used to detect showers with high spatial resolution. This imaging power can be exploited at future linear collider experiments where the measurement of jet energy by a Particle flow method requires optimal use of tracking and calorimeter information. Gaseous detectors can achieve high granularity and a hadron sampling calorimeter using Micromegas chambers as active elements is considered in this paper. Compared to traditional detectors using wires or resistive plates, Micromegas is free of space charge effects and could therefore show superior calorimetric performance. To test this concept, a prototype of 1×1 m2 equipped with 9216 readout pads of 1×1 cm2 has been built. Its technical and basic operational characteristics are reported.