Advancements in the simulation of environmentally friendly gas mixtures for Resistive Plate Chambers

Abstract

Resistive Plate Chambers (RPCs), widely used in particle detection, offer high efficiency, excellent time resolution, and cost-effectiveness. The environmental impact of gases such as tetrafluoroethane and sulfur hexafluoride, commonly used in RPCs, has driven research into more sustainable gas mixtures.

This study explores the accuracy of simulating the electron swarm parameters in environmentally friendly gas mixtures for RPCs, particularly focusing on the potential substitution of the gas tetrafluoroethane (C₂H₂F₄) with tetrafluoropropene (C₃H₂F₄). Using Monte Carlo simulations with the MATOQ framework, we demonstrate agreement with experimental measurements recently obtained from RPCs operating with C₃H₂F₄-based gas mixtures at room temperature and atmospheric pressure. This confirms the accuracy of the electron collision cross sections for C₃H₂F₄ available in the literature, extending their validation from 45 kPa to atmospheric pressure, and strengthening their reliability for simulations focused on RPC applications.

The benchmark of electron collision cross sections for C₃H₂F₄ paves the way for future research aimed at optimizing environmentally friendly gas mixtures for RPCs. Results of this study show that the effective Townsend coefficient can vary by more than an order of magnitude when C₃H₂F₄ is mixed with molecular oxygen, nitrogen, carbon dioxide, argon, or helium. These findings support a viable strategy for lowering the working point of RPCs by combining C₃H₂F₄ with another gas that has a low global warming potential, as demonstrated by various experimental studies. Variations in electron drift velocity, a key factor in determining the time resolution of RPCs, have also been observed when C₃H₂F₄ is combined with the aforementioned atmospheric gases.