Development of GEM based digital hadron calorimeter

The University of Texas at Arlington High Energy physics group and its collaborators have been working on developing a digital hadron calorimeter (DHCAL) using GEM technology for the past several years. The group developed a large scale (30 cm x 30 cm) GEM foils with 3M micro-pattern circuit division and constructed several prototype chambers. In addition to the characterizations carried out at particle beams with previous generation of prototype chambers, the group has been working on multiple channel analog readout of the chamber with KPiX 13 bit analog chip developed by the SLAC National Laboratory team for silicon-tungsten electromagnetic calorimeter. This paper reports on the latest results using the multiple channel readout of the prototype chamber and the future plans for DHCAL development activities.