Moderation of photochemically generated hot hydrogen atoms

Abstract

Hot hydrogen atoms generated by photolysis of gaseous HI react with OCS to produce CO by eqn (1). H^*+ OCS → CO + SH (1). This reaction has been used to examine the moderation of the hot atoms by added C₂H₆, C₃H₈, n-C₄H₁₀, CH₃F, C₂F₆, C₃F₈ and SF₆. In each case the value of the energy-loss parameter α, relative to that for argon, is greater than that calculated assuming elastic collisions between the hot atom and moderator. Alkanes are the most efficient of the moderators examined, with relatively minor differences in α for C₂H₆, C₃H₈ and n-C₄H₁₀.