Conductometric study of the radial track etch rate: Free shape analysis

A general formula for data analysis in conductometric experiments on latent track structure has been obtained without any pore shape assumption. An iterative equation, which was derived from pore geometry defined in a rest frame model, enables us to estimate the precise pore shape of the latent tracks during an etching. Polyethylene terephthalate (PET) films irradiated by Kr ions have been studied by this iteration technique. Radial etch rates reach convergence after a few iteration cycles and are less affected by the error of the breakthrough time. The iteration technique also reveals that a cylinder approximation, which is widely used for calculating a pore size, overestimates the transverse size of etched heavy ion tracks in the range less than 10 nm. (C) 2000 Elsevier Science B.V. All rights reserved.