Beam test of a small MICROMEGAS DHCAL prototype

Abstract

A sampling hadronic calorimeter with gaps instrumented with thin MICROMEGAS chambers of small pad size and single bit readout is a candidate for an experiment at a future linear collider. Several MICROMEGAS chambers with 1 cm2 anode pads were fabricated using the Bulk technology. Some prototypes equipped with analog readout GASSIPLEX chips were developed for characterisation at the CERN/PS facility. A stack of four chambers and stainless steal absorber plates was used to assess the behaviour of MICROMEGAS in 2 GeV electron showers. Longitudinal and transverse shower profile are shown. The Bulk fabrication process was adapted to laminate a mesh on anode PCBs with front-end chips connected on the backside. It is well suited for the construction of a 1 m3 DHCAL- MICROMEGAS prototype as large and thin chambers can be made. Such chambers with digital readout chips (HARDROC or DIRAC) were fabricated and tested in a beam. First results are presented.