Irradiation Decomposition of Carbon Dioxide

Abstract

DURING investigation of the reaction between carbon dioxide and graphite induced by radiation, we have examined the decomposition by irradiation of carbon dioxide in the absence of graphite. These irradiations have been carried out in transparent silica vessels into which the required amounts of carbon dioxide are condensed before sealing off. Particular care was taken to exclude organic contaminants by cleaning the silica vessels, wool and rods in hot chromic acid, followed by three washings in hot distilled water and firing at 1,000° C. for 2 hr. in an atmosphere enriched with oxygen. Carbon dioxide was prepared from ‘Cardiee’, distilling three times before use, with rejection of first and last fractions. Mercury vapour was eliminated by the use of a trap at −78° C. placed immediately before the vessels to be filled. Analysis of the gas after irradiation was carried out by a gas chromatographic method¹. The samples received a thermal neutron dose of 2.3 × 10¹⁸ n.cm.⁻² in the core of the Harwell reactor Bepo. From the integrated dose of thermal neutrons as measured by cobalt wires, the energy dose received by the carbon dioxide was calculated using the calorimetric data of Anderson and Waite².