Measurements and calculations of gas gains in methane-based TEG mixtures

Abstract

The gas gains in the methane-based tissue equivalent gas (TEG) mixture (64.4% CH4 + 32.5% CO2 + 3.1% N-2) were measured in single wire proportional counters and calculated with Magboltz simulation program for various mixture pressures. The calculated gain values were always greater than the measured ones for all pressures. The source of the discrepancies was investigated in terms of dissociation of the molecules and non-equilibrium conditions. The impacts of both energy loss mechanisms on gas gain rise as the mixture pressure decreases.