Ion Track Technology

PhysicsConsult

Reimar Spohr

PostHeaderIcon Abstract

Tracks of very heavy ions in polymers. P. Apel, A. Schulz, R. Spohr, C. Trautmann, V. Vutsadakis. Nuclear Inst. and Methods in Physics Research, B 131 (1997) 55-63.

A comparative study of latent and etched track parameters in various polymers is performed with the emphasis on the tracks of very heavy particles such as 238U ions in the energy range of 1–11.6 MeV/u. Samples of polyethylene terephthalate (PET), polypropylene (PP) and polysulphone (PSU) films were irradiated with heavy ions of various masses. The etching kinetics of the tracks in PET were investigated by a conductometric technique. The sizes of a highly damaged "track core" and a cross-linked "halo" were derived from the kinetics of the etching curves for the ions of various masses. The ratio of track to bulk etch rate, V, was determined as a function of the ion energy loss, dE/dx. In the case of PP a distinct maximum of the V(dE/dx) function at dE/dx = 7 keV/nm was observed. No profound increase of V was observed when passing from Xe to U tracks in both PET and PSU. Obviously, at very high energy losses the destruction and construction processes coexist and the relative role of construction increases at a certain level of dE/dx. The experimental data seem to indicate that accelerated ions of moderate masses are favoured for the production of structures with a high aspect ratio.