Ionization coefficients and sparking voltages in argon-long-chain hydrocarbon gas mixtures†

Townsend primary and secondary ionization coefficients and the sparking voltage have been measured in 0[sdot]003, 0[sdot]03, 0[sdot]3 and 3% of n-octane. cis.bntetio-2 and benzene mixed in argon for u total pressure in the range 0[sdot]5 to 500 torr and for a uniform field gap up to 1 cm. The increase in the Penning effect and in the effectiveness of quenching with increase in chain length of the paraffin gas mixtures is not maintained in argon-n-octane because of the increase in the resonance defect. The ionization and breakdown properties of argon-benzene and argon cis-butene-2 are very similar. 0–0[sdot]3% n-pentane-argon offers the lowest sparking characteristic of all hydrocarbons tested. Benzene in argon produces the greatest quenching effect. The greatest Penning effect is observed in argon-0[sdot]3% acetylene.