Speaker
Description
Resistive Plate Chamber (RPC) detectors are widely used at the CERN LHC
experiments as muon trigger thanks to their excellent time resolution. They are
operated with a gas mixture containing R-134a and SF6, both greenhouse gases
(GHG) with a very high global warming potential (GWP). The search of new
environmentally friendly gas mixtures is necessary to reduce GHG emissions
and costs as well as to optimize RPC performance. Several recently available
gases with low GWP have been identified as possible replacements for R-134a
and SF6. The addition of CO2 to the gas mixture was studied as possible mid-
term solution to mitigate R-134a usage, while R-1234ze was studied as a possible
replacement for R-134a. The RPC detectors were tested in laboratory conditions
and a set of selected mixture was then tested at the CERN Gamma Irradiation
Facility (GIF++), which provides a high energy muon beam combined with
an intense gamma source allowing to simulate the background expected at HL-
LHC. The performance of RPCs were studied at different gamma rates in a
presence of muon beam by measuring efficiency, streamer probability, induced
charge, cluster size and time resolution.
