Dosimetry for radiation emergencies: Radiation-induced free radicals in sugar of various countries and the effect of pulverizing on the ESR signal

Abstract

Household sugar has been proposed as a dosimeter for radiation emergencies, since radiation-induced free radicals in sucrose are known to be relatively stable and can readily be analyzed by the electron spin resonance (ESR) method. Elemental impurities in crystalline sugar produced in 19 countries were investigated with ESR spectroscopy. Certain characteristic contributions to the ESR signal from trace elements were not detected in any of the sugar samples. No difference in the radiation-induced properties, i.e. ESR sensitivity and decay of the ESR signal intensity, was observed with sugar produced in any of 19 countries. The induction of free radicals when sugar crystals are ground into fine powder or are irradiated by γ rays was compared by ESR spectroscopy, as a means of testing the possible differences between the response of sugars in the various sugar-producing countries. The maximum equivalent radiation absorbed dose caused by the powdering of sugar reached about 10 Gy. The precision of the ESR measurement observed with only one sample tube is much greater than the precision between several different samples. Furthermore, it was found that both the radiation-induced and pulverization-induced free radicals in sugar are quite stable, even when heated to near the melting point.