Primary yields and mechanism in the radiolysis of gaseous ammonia

Ammonia vapor has been irradiated with single pulses of electrons at a very high dose rate (10 27 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 10 27 eV g −1 s −1 are: G(H 2 ) = 3.58 ± 0.08; G(N 2 ) = 1.00 ± 0.05; G(N 2 H 4 ) = 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 G NH = 0.74; [Formula: see text]; G H = 4.8; and G(−NH 3 ) = 5.4.