Electron scavenging in the radiolysis of supercritical ethane, ethylene, n -butane, and isobutane

Abstract

Free ion yields in the radiolysis of supercritical ethane and ethylene at 50°C, and n ‐butane and isobutane at 170°C were estimated as a function of density from the nitrogen yields observed upon electron scavenging by N₂O with the use of the square root model, G(N₂)=G(N₂)_fi + G(N₂)_gi(A[N₂O])^1/2. The estimated G_fi in the hydrocarbon gases were in the decreasing order C₂H₆ > i −C₄H₁₀ > n −C₄H₁₀ > C₂H₄ for the density range 0.12–0.24 g/ml. The density‐normalized range of electrons estimated from G_fi values decreased sharply with an increase in density for C₂ hydrocarbons, while it was practically constant for butanes over the entire range studied (0.12–0.42 g/ml). The variation of A values with density was discussed in terms of the concomitant change in the electron mobilities.