New RPC gas mixtures for sustainable operation in the CMS experiment

The current operation of the Resistive Plate Chamber (RPC) system within the CMS experiment involves approximately 95% tetrafluoroethane (C 2 H 2 F 4 , TFE). However, in response to climate change concerns, the European Union has instituted a ban on TFE owing to its elevated Global Warming Potential (GWP), resulting in an associated increase in market prices. In this framework, shared endeavors within the RPC EcoGas@GIF++ Collaboration, have been dedicated to investigating novel ecological gaseous mixtures based on tetrafluoropropene (C 3 H 2 F 4 , HFO-1234ze) to ensure the sustainable functionality of RPCs. This presentation will delve into the performance outcomes derived from improved RPC gas gaps operating on HFO/CO 2 -based mixtures as ecologically viable alternatives, particularly in anticipation of the High Luminosity LHC phase (HL-LHC). Additionally, the utilization of TFE/CO 2 mixtures will be explored as a pragmatic strategy to swiftly alleviate gas-related operational costs.