Energy transfer in the gamma radiolytic decomposition of sodium and potassium nitrates dispersed in phosphate, sulfate and carbonate matrices in solid state

Abstract

Gamma radiolytic decomposition of sodium and potassium nitrates dispersed in respective phosphate, sulfate and carbonate matrices has been studied over a wide absorbed dose range upto 300 kGy. Decomposition of nitrates increases with the concentration of the additive in the admixtures. G(NO⁻ ₂) values, calculated on the basis of electron fraction of the nitrate decreases with the absorbed dose and with the increasing concentration (or mol %) of the nitrate. Thermoluminescence (TL) and Electron Spin Resonance (ESR) studies suggest the formation of radical species which may interact with NO⁻ ₃ causing enhancement in the decomposition process. A comparison of G-values for three additives suggests that the efficiency of the energy transfer decreases in the order PO^3- ₄ > CO^2- ₃ > SO^2- ₄ and depends on the nature and the concentration of the additive as well as the nature of cation/anion.

Key Words:

• Additives
• phosphate
• sulfate
• carbonate
• nitrate
• G(NO⁻ ₂)
• energy transfer
• radical species