Construction of a technological semi-digital Hadronic calorimeter prototype for ILC

A high-granularity semi-digital Hadronic calorimeter using GRPC as sensitive medium is to be proposed for the future International Linear Collider project. A prototype of 1m³ has been conceived within the CALICE collaboration in order to validate this option. The prototype intends to be as close as possible to the one proposed in the ILD Letter Of Intent. Few units made of 1m² GRPC fully equipped with semi-digital readout electronics and new gas distribution design were produced and successfully tested. The production of 40 similar units to be inserted in a self-supporting mechanical structure has started. The prototype will then be exposed to test beams at CERN for final validation.