Model for Neutralization and Scavenging of Charges in Irradiated Dielectric Liquids. I. Evolution of the Neutralization Process in Multiple Ion-Pair Cases

Abstract

A diffusion model has been constructed for calculating the survival probability, as a function of time, against neutralization in multiple ion‐pair cases in irradiated dielectric liquids. Such situations are generated by the absorption of a substantial amount of energy in a relatively small region. The geometry of the region is taken as spherical for energy deposit $\text{〈 500}\mathrm{eV}$ and as cylindrical if energy deposit is $\text{≥ 500}\mathrm{eV}$ . The infinite‐time limit of the so‐calculated survival probability gives the probability of escaping charge neutralization which is calculated and compared with two experiments. The agreement is satisfactory. The mutual electrostatic interaction between the charges is considered through a screened field within the framework of prescribed diffusion. The relevant Smoluchowski equation is then integrated in time to give the desired survival probability. Special considerations, as described in the text, are necessary at long time limits. The results are compared between the two geometries used here and also with earlier work on isolated ion pair.