Speaker
Description
The effort to redesign the RPCs for the future experiments muon systems has started shortly after the beginning of the LHC experiments and recently centered the goal of producing a 100 x 50 cm2 size prototype. This prototype inherits from the present ATLAS muon trigger chambers the basic design and simple construction features and bi-dimensional strip readout, but is equipped with a newly designed 1 mm gas gap with 1.2 mm HPL electrodes with a resistivity of about 1x1011Ωcm. An highly sensitive front end electronics, working with just 103e− of noise has been embedded directly in the RPC faraday cage, within the thickness of the readout panels. The combination of high sensitivity, large dimension and bi-dimensional readout represents a major challenge in building the prototype with specific reference to the Faraday cage structure. The result was such that the settable threshold is limited just by the intrinsic electronic noise, even in extremely noisy environment, such as the beam facility H4 of CERN, where the prototype has been tested with the GIF++ 137Cs photons and a muon beam. In this talk we will present the chamber performance operated at full efficiency in presence of a photon induced counting rate of the order of 10 kHz cm−2, notwithstanding the relatively high electrode resistivity.
