γ-Radiation induced isotope exchange in the carbon monoxide-carbon dioxide system. Studies in silica vessels

Abstract

The behaviour of the isotopes ¹³C, ¹⁴C and ¹⁸O in the CO—CO₂ system in silica vessels has been studied, and the usefulness of the system as a radiation dosimeter investigated. Each insotope has been employed under identical conditions. For the exchange of an oxygen atom between CO and CO₂ the established G-value of 4.2 has been confirmed. Apparent anomalies between results involving carbon- and oxygen-isotope labelling have been explained by a schematic initial reaction scheme involving participation of the silica: [graphic omitted] (1), (¹⁸O)+ C¹⁶O→C¹⁶O¹⁸O (2), [graphic omitted] (3a), (C¹⁸O +¹⁶O)_ads.Si¹⁶O¹⁸O→Si¹⁶O¹⁸O + C¹⁸O +(¹⁶O)(3b), (¹⁶O)+ C¹⁶O→C¹⁶O¹⁶O (4), (¹⁶O)+ C¹⁸O→C¹⁶O¹⁸O (5).