RADIATION INDUCED REACTIONS IN THE SYSTEM, CARBON DIOXIDE, CARBON MONOXIDE, GRAPHITE

Presented at the Libby-Cockcroft Meeting on Gas Coolant Compatibility, Harwell, Berks, England, April l962. A discrepancy reported in the recent summary report was traced to the presence of mercury in the bulbs irradiated in the early stages of the work. This mercury causes a reduction in the yields of carbon monoxide by a factor of about two for bulbs with axial graphite specimens. Consistent behavior was obtained in a number of experiments where mercury was systematically added. Different but self-consistent results were obtained by reduction of mercury to a low level. Anomalous results were obtained at low carbon dioxide filling pressures. Possible causes are suggested and work is in progress to examine this pressure region more carefully. Irradiation of carbon dioxide and graphite to high doses produces visible black or brown deposits. The carbon monoxide content obtained in these irradiations appears to reach a limit which is not exceeded on further irradiation. This limit is dependent upon the initial carbon dioxide filling pressure and the geometrical arrangement of graphite specimen in the buib. The irradiation of carbon monoxide-carbon dioxide mixtures in the presence of similar graphite specimens brings about changes such that the composition of the gas mixtures tends towardsmore » this limit. The irradiation of carbon monoxide alone and in the presence of graphite was studied. The stoichiometry appears to correspond to 3 CO yields CO/sub 2/ + solids. (auth)« less