Radial size and chemical structure of nuclear tracks in polymers

The radial size and chemical structure of latent tracks in CR-39 plastics and other polymers for heavy ions has been studied. AFM observations were performed on the irradiated CR-39 subsequent to the slight chemical etchings. The track core radii for C, O, Ne, Fe and Xe ions evaluated from the intersections of the extrapolated lines, fitted to each growth curve of etch pit radius, were found to be in the range between 2 and 8 nm. UV-visible spectra of the irradiated CR-39 were obtained at various fluences. Based on a track overlapping model, the track core radii are evaluated for O, Ne, Ar, Si and Fe ions. Local dose at track core radii of heavy ions in CR-39 were assessed based on the dose distribution model by R.Katz. (author)