Environment-friendly gas mixtures for Resistive Plate Chambers: an experimental and simulation study

Abstract

Resistive Plate Chambers (RPC) have shown stable operation at the Large Hadron Collider and satisfactory efficiency for the entire Run 1 (2010-2013) and Run 2 (2015-2018) with C${}_2$H${}_2$F${}_4$-based gas mixtures and the addition of SF${}_6$ and i-C${}_4$H${}_{10}$. Since its global warming potential (GWP) is high, C${}_2$H${}_2$F${}_4$ is phasing out of production due to recent European Union regulations and as a result its cost is progressively increasing. Therefore, finding a new RPC gas mixture with a low GWP has become extremely important. This contribution describes the simulation of the RPC efficiency with tetrafluoropropene C${}_3$H${}_2$F${}_4$ (HFO1234ze), a hydrofluoroolefin with very low GWP. Simulation results are systematically compared with measurements of RPC efficiency in C${}_3$H${}_2$F${}_4$-based gas mixtures with the addition of different combinations of Ar, He, CO${}_2$, O${}_2$ and i-C${}_4$H${}_{10}$ in various concentrations. This simulation allows the study of the interplay between C${}_3$H${}_2$F${}_4$ and the other gas components in the mixture as well as may allow the identification of the most promising environment-friendly gas mixtures with C${}_3$H${}_2$F${}_4$ for RPCs.

15th Workshop on Resistive Plate Chambers and Related Detectors (RPC 2020)