Ion tracks in an organic material: Application of the liquid drop model

The liquid drop model (LDM) was developed to perform radiation damage studies in metals in an ionic energy range where molecular dynamics cannot be used because of computational restraints. In this work, the model is extended in an effort to explain the observation of tracks in organic insulators in an energy range here other theoretical models fail. The detector material was Makrofol E and the studied ions had specific energies between 1.4 and 100 keV/n. The tracks were observed via a replica method by transmission electron microscopy. The electronic, as well as the nuclear energy deposition by an individual ion were considered, then the thermal spike evolution is studied. The LDM predicts track diameters much larger than previous models. Most of these tracks now can be developed. Although the model still has free parameters and shows some discrepancies with experimental data, its agreement is better than that obtained through the consideration of other models. (C) 2001 Elsevier Science B.V. All rights reserved.