Particle identification in the low-GeV/c regime using Octafluoropropane (R-218) as Cherenkov radiator

Particle identification with threshold Cherenkov detectors, using a moderately pressurized radiating gas with an adequate refractive index, is one of the most common techniques employed in high-energy physics. However, available gases with relatively high refractive indices, that simultaneously preserve their gaseous phase at room temperature and moderate pressures, are rare. Until recently, R-12 (Freon-12) was broadly used, but to date, it is generally unavailable due to its high global warming potential. In this work, we present an estimation of the refractive index of an alternative gas, Octafluoropropane (R-218), and we explore its feasibility as a Cherenkov radiator, for tagging charged particles at momenta as low as 2 GeV/c.