Ammonia vapor has been irradiated with single pulses of electrons at a very high dose rate (1027 eV g−1 s−1) with a Febetron 705. At this dose rate radical–product reactions are not significant. In pure ammonia, hydrogen, nitrogen, and hydrazine are produced and the yields found at 1027 eV g−1 s−1 are: G(H2) = 3.58 ± 0.08; G(N2) = 1.00 ± 0.05; G(N2H4) = 0.58 ± 0.05. The yields are independent of pressure from 1 to 5 atm and of temperature between 20 and 200 °C. Above 250 °C the yields of all three products increase significantly and this is due to reaction [1] competing with radical–radical reactions.[Formula: see text]A rate constant for this reaction has been determined,[Formula: see text]Product yields have been measured for ammonia–propene mixtures. These yields have allowed determination of the primary radiation yields GNH = 0.74; [Formula: see text]; GH = 4.8; and G(−NH3) = 5.4.

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Eyre and Smithies have recently obtained radical yields of G N H~ = GH = 10.4 in the radiolysis of gaseous ammonia. The consistency of these with Nz, Hz, and N2H4 yields obtained in the high dose rate radiolysis of NH, and NH3-C3H6 mixtures has been shown by numerical integration of the rate expressions in a simple radical mechanism. These calculations give a value of 2.1 + 0.5 x 10" M-' s-' for the reaction of H atoms and NHz radicals and a ratio of recombination to disproportionation of 6:l.

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