The energy required to produce an electron‐ion pair (i.p.), W , for the α‐particle irradiated gases CF 4 , C 2 F 6 , C 3 F 8 , and n ‐C 4 F 1 0 has been measured and found to be 34.3, 34.5, 34.4, and 34.2 eV/ i.p., respectively. The large values of W for these perfluorocarbons (PFCs) are attributed to their large cross sections for electron impact‐induced dissociation. The constancy of W for this group of molecules is discussed with respect to the constancy of the ratio (∼0.68) of the respective (energy integrated) total ionization cross section to the total (energy integrated) inelastic scattering cross section. W values are also reported for the binary gas mixtures Ar/CF 4 , Ar/C 2 F 6 , Ar/C 3 F 8 , and CH 4 /CF 4 which have conduction and insulation properties suitable for use in diffuse discharge opening switches. The W values for these binary mixtures (and for C 2 H 2 /CF 4 , C 2 H 2 /C 2 F 6 , and C 2 H 2 /C 3 F 8 ) increase with the amount of PFCs in the mixture and (contrary to the Ar/C 2 H 2 mixture) exhibit no Jesse effect. The ternary gas mixtures Ar/C 2 H 2 /PFC (=CF 4 , C 2 F 6 , C 3 F 8 ) containing ≲10% PFC were found to exhibit a pronounced Jesse effect which is a function of the content of the PFC in the mixture and the electron scattering cross section of the PFC itself. Substantial increases in ionization can be achieved by adding to the Ar/PFC binaries 1–3% of C 2 H 2 . An analysis of the W data yielded information on the partition of the α particle’s energy among the gas components and indicated that the rate constant for energy transfer from excited argon atoms (Ar∗) to the PFC is smaller than that from Ar∗ to C 2 H 2 ; it showed, also, that the rate constant for energy transfer from Ar∗ to C 2 H 2 is ∼10 4 larger than that for collisional deexcitation of Ar∗ by ground‐state Ar atoms. The quantitative measurements reported herewith and the parameters deduced from a simple modeling of the data permit the tailoring of ternary gas mixtures with substantial current increases over those achieved in the binary Ar/PFC (=CF 4 , C 2 F 6 , C 3 F 8 ) mixtures which possess the desirable conduction and insulation characteristics for pulsed power opening switches.
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