Radiation chemistry of gaseous ammonia. Part 1.—Radical and molecular product yields

Abstract

The effects of temperature and various additives have been studied in the 1.0 MeV electron radiolysis of gaseous ammonia. A non-scavengable hydrogen yield of G_H2= 0.75 ± 0.05 was obtained in ethylene + ammonia mixtures and an H-atom yield of G_H= 12.5 ± 1.0 was obtained in hydrazine + ammonia mixtures at 23°C, consistent with results in deuterium + ammonia mixtures at low NH₃ pressures. Product yields in pure ammonia increase with increasing temperature up to limiting values obtained at 300°C and above. The primary decomposition yield of G_–NH3= 15.1 at 300°C is larger than the yield G_–NH3= 14.0 at 23°C. Large amounts of HD are produced by a chain mechanism in the radiolysis of D₂+NH₃ mixtures at 200°C.