Interpretation of the Effects of Ionic Scavengers at High L.E.T. in Irradiated Cyclohexane, Based on Ambipolar Diffusion

Abstract

Some results on the effects of ionic scavengers in cyclohexane irradiated at high L.E.T. are reinterpreted on the basis of ambipolar diffusion. It is shown that at high L.E.T., 200 keV µm–1, the density of ions is great enough for ion atmospheres to be set up, so that the diffusion of oppositely charged ions is mutually influenced (the Debye length is much smaller than the track radius), throughout the significant lifetime of the track. Expressions are derived for the relevant ambipolar diffusion constants with scavenging occurring, which change as scavenging and neutralization of ions take place. These, applied to a diffusion model of the track, yield curves of G(scavenged ions) against scavenger concentration which agree well with experiment. These concepts should be helpful in interpreting the scavenging of ions produced by the high L.E.T. component of γ and fast electron irradiation.