Kinetic and fluid studies on Resistive Plate Cambers operated with new eco-friendly gas mixtures

Resistive plate chambers (RPCs) are parallel plate gaseous detectors commonly used for timing and triggering purposes in many high-energy physics experiments. RPCs are employed at CERN-LHC (Large Hadron Collider) experiments due to their excellent time resolution, high-rate capability, and relatively low production cost (Rigoletti et al. 2020). They also play a key role in direct measurements of muons in air showers (Abreu et al. 2018) and in some neutrino observatories (Kumar et al. 2017). RPCs are operated with a gas mixture consisting of C2H2F4 (between 90% and 95%), a smaller fraction of i-C4H10 (around 5%) and SF6 (usually between 0.3% and 1%). C2H2F4 and SF6 are well-known greenhouse gases with a global warming potential of respectively 1430 and 22800. The substitution of C2H2F4 and SF6 with environmentally friendly alternatives is one of the major challenges in current RPC technology. C2H2F4 can be substituted with either a mixture of C2H2F4 and CO2, or a mixture of C3H2F4 and CO2, or eventually a mixture of C3H2F4 and He (Rigoletti et al. 2020, Abbrescia et al. 2024). On the other hand, CF3I, C4F7N and C5F10O were considered as alternatives to SF6 (Guida et al. 2022). The performance of the detector, including detection efficiency, time resolution, and streamer occurrence, with these gases and mixtures has only been tested experimentally so far. This work presents the first comprehensive modelling study of RPCs that operate with the new generation of environmentally friendly gases and corresponding mixtures.We approached the problem in three stages. We start by presenting completeand consistent cross-section sets for electron scattering in C2H2F4 and C3H2F4. A cross-section set for electron scattering in C3HF5 is also developed, as this gas could also be considered as an alternative to C2H2F4. The accuracy of cross-section sets was tested and validated through a series of comparisons between swarm data calculated using a numerical solution of Boltzmann’s equ ... - FULL TEXT available in PDF.