Ionization of Liquids by Radiation. II. Dependence of the Zero-Field Ion Yield on Temperature and Dielectric Constant

Publisher Website
Google Scholar
Abstract
The positive‐ and negative‐ion mobilities and the yield of separated ion pairs have been determined for irradiated hexane over the temperature range 200°—300°K, and for carbon tetrachloride and 1,4‐dioxane at room temperature. The effect of radiation quality on the ion yield in hexane was also studied. The ion mobilities were changed in hexane by small amounts of added foreign substances. The temperature coefficient of mobility is greater than that of the solvent viscosity for both positive and negative ions in hexane. Our data do not allow any firm conclusion regarding the nature of the negative ion in pure hexane. The data on ion yields in hexane are discussed in terms of the theoretical energy‐loss spectrum of the primary fast electron which is responsible for the ionization, and Onsager's expression for the escape probability on an ion pair formed near to each other in a fluid medium. The number of high‐energy secondaries (above 1000 eV) is much too small to account for the observed yields of separated charge. It is concluded that electrons, generated by ionization with kinetic energies below 100 eV, travel much farther on the average from their parent ions than would be expected by extrapolation of electron ranges measured at higher energies.

This publication has 18 references indexed in Scilit: