Theory of Radiation Chemistry. VII. Structure and Reactions in Low LET Tracks

Abstract

The low LET track of an electron is composed of a random sequence of more or less isolated entities called spurs, blobs, and short tracks. The distribution function for these track entities has been considered in detail by a Monte Carlo technique. In order to evaluate the effect of the more accurate structure on calculated chemical yields, as contrasted with the simpler spur model, the diffusion equations were solved numerically for the one radical case. The more elaborate track model introduced here has a kind of high LET component embedded in it through the ``short tracks.'' This investigation shows that for electron irradiations all LET effects result from the variation in fraction of energy deposited in short tracks. Effects of overlapping of various track entities during the diffusion and reaction phase are negligible.