Energy partition in the γ-radiolysis of gaseous H2S + N2O mixtures

Abstract

Measurement of ion yields G_m(= 100/W_m), where W_m is the average energy required to produce an ion pair in the mixture) in gaseous H₂S—N₂O mixtures indicates that the energy partition parameter “a”= 0.53 holds for mixtures of stopping power fraction Z=P₁[P₁+(S₂/S₁)P₂] from 0.15→1.0, and perhaps over the whole range of Z. P₁ and P₂ are the partial pressures and S₁ and S₂ are the stopping powers relative to air of H₂S and N₂O respectively. The radiation yields of H₂ and N₂ in the mixtures G(H₂)_m and G(N₂)_m yield this value of “a”= 0.53 probably restricted to the range Z= 0.45 → 1.0. A scheme of energy transfer from an excited state of N₂O to H₂S is suggested for the deviation below Z= 0.45. For Z > 0.45 an excited state of N₂O is postulated that does not transfer energy to H₂S. A mechanism of ionization energy transfer plus reactions of O and NO₂ with H₂S is suggested as an explanation of the high sulphur yields at low Z.