Pulse radiolytic studies of supercritical CO2

The species produced by ionizing radiation in supercritical CO2 have been measured at a reduced temperature of 1.03 from 78 to 117 bar. It has been shown that C2O4+ is formed. This then reacts with positive ion scavengers. Its rate constant with dimethylaniline is 1.2×1011 l mol−1 s−1 at 104 bar. The amount of C2O4+ formed is not proportional to the CO2 density. This is attributed to an increased escape of the geminate ions at lower densities. We have also measured the production of ozone, which implies the production of O atoms and a production of oxygen molecules.