Progress towards a Technological Prototype for a Semi-Digital Hadron Calorimeter based on Glass RPCs

The semi-digital Hadronic calorimeter using GRPC as sensitive medium is one of the two options the ILD collaboration is considering for the ILD detector final design. A prototype of 1m3 has been conceived within the CALICE collaboration in order to validate this option. The prototype is intended to be as close as possible to the one proposed in the ILD LOI. A first unit of 1m2 GRPC of 3 mm thickness and fully equipped with a semi-digital electronics readout and new gas distribution design was produced and successfully tested. In 2010 we intend to produce 40 similar units to be inserted in a self-supporting mechanical structure. The prototype will then be exposed to test beams at CERN or at Fermilab for final validation