N–O bearing molecules produced by radiolysis of N2O and N2O:CO2 ices

Abstract

N2O and CO2 can be formed in the interstellar space and in ices on the surface of outer solar system bodies, such as Pluto and Triton. Energetic ions can simulate the energy transfer processes that occur by cosmic ray irradiation of interstellar ices, comets, and icy solar system bodies. Proceeding systematic research, pure nitrous oxide (N2O) ice, and nitrous oxide and carbon dioxide (CO2) ice mixture were irradiated at 11 K with MeV-nitrogen (N+) and -xenon (Xe23+) ion beams. The chemical and physical effects induced by ion irradiation on the N2O ice and the N2O:CO2 ice mixture are compared. The formation and dissociation cross sections scale with the electronic stopping power (Se) roughly as σ ∼ a Sen, where n ∼ 3/2. The n power law is helpful for predicting the N2O formation and dissociation cross-sections for other ion beam projectiles and energies; these predictions will allow estimating the effects of the entire cosmic ray radiation field.