Development of a semi-digital hadronic calorimeter using GRPCs for future linear collider experiments

A new concept of high granularity hadronic calorimeter using thin GRPCs as sensitive medium with embedded semi-digital readout electronics to be used in the future linear collider experiments is under development within the CALICE collaboration. Based on this concept, a small prototype was built and tested with success at CERN PS test beam in 2008. To validate completely this new concept a prototype of 1 m³ is being conceived. Few GRPCs as large as 1 m² were built with a new design reducing the dead zones and improving on the gas distribution system. The GRPCs were tested with an electronics board of the same size. The board containing 144 of 64-channel ASICs was conceived and built for this purpose. It represents the largest ever built with the embedded electronics scheme.