Chemical Yields of Ionizing Particles in Aqueous Solutions: Effect of Energy of Protons and Deuterons

Abstract

Chemical effects produced in aqueous solutions by ionizing radiations are known to depend on the energy and mass of the ionizing particles. Light-particle radiations yield predominantly free radicals, whereas heavy-particle radiations yield principally hydrogen and hydrogen peroxide (1-4). According to current theory, hydrogen and hydrogen peroxide originate by a recombination of the primary hydrogen and hydroxyl free radicals in the track before appreciable diffusion takes place. As the density of ionization along the particle track increases, the greater becomes the probability of recombination, and consequently the yield of hydrogen and hydrogen peroxide is greater. The present work was undertaken to supply ferric ion yields for protons in the energy range from 0.3 to 2.0 Mev and for deuterons in the range from 3.5 to 21.2 Mev. This work was carried out with the Fricke and ferrous sulfate-cupric sulfate dosimeters. In the former dosimeter the free radical plus molecular hydrogen peroxide yields are measured, whereas in the latter dosimeter only the hydrogen perodixe formed in equimolar amounts with hydrogen is measured (5). G(Fe+++) and G(Fe+++ Cu++) experimental quantities obtained by the use of these dosimeters are interpreted in terms of free radical and molecular product yields for the decomposition of water by protons and deuterons.