Numerical qualification of eco-friendly gas mixtures for avalanche-mode operation of resistive plate chambers in INO-ICAL

Proposition and qualification of an eco-friendly gas mixture of Ar(5%):CO₂(60%): N₂(35%) for operating Resistive Plate Chambers of INO-ICAL experiment in avalanche mode is the soul of this work. The detector efficiency and streamer probability for the proposed mixture have been simulated using a hydrodynamic model developed by us. Efficacy of the mixture has been studied by comparing the simulated results to available experimental data for the standard gas mixture of R134a(95.2%):i-C4H10(4.5%):SF6(0.3%) to be used in INO-ICAL, as well as the same observables measured for other eco-friendly hydrofluoroolefin (HFO1234ze)-based potential replacements. To reduce the streamer probability of the proposed argon-based gas mixture at higher voltages, the usual practice of adding a small amount of electronegative gas SF₆ has been tested. An alternative approach of lowering electronic threshold has been investigated as well for the same purpose.