Abstract for the Fourth Foresight Conference on Molecular Nanotechnology.

Direct observation of latent nuclear tracks in organic material by atomic force microscopy

N. Rozlosnik (a) L.S. Bohus (b) C. Birattari (c) L. Biro (d) K. Havancsak

Dr. Noemi Rozlosnik
Dept. of Atomic Physics, Eotvos University, Budapest, Hungary
H-1088. Budapest, Puskin u. 5-7.
Hungary, Europe
Tel: 361-2667902
Fax: 361-2660206
Email: noemi@ceasar.elte.hu
Position: associate professor
L.S. Bohus
Dept. de Fisica, Universadad Simon Bolivar, Caracas, Venesuela
C. Birattari
Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Italia
L. Biro

Latent nuclear tracks are damaged zones, created along the paths of speedy heavy ions moving in solids. Although a lot of simple or more complicated model exist, we do not yet have a satisfactory explanation for the production of latent tracks in solids by highly energetic ionizing charged particles. The direct image of the surface morphology of these track made by atomic force microscope gives new information about it. Nuclear track recording solids, in wich tracks can be enlarged to visible size by chemical etching, have found wide application. Among these the so-called CR-39 is one of the most homogeneous polymer with which high resolution and sensitivity can be achieved. In a systematic study of the properties of track formation the recording material should be isotrop, which can be satisfied only by totally amorphous polymer.

In our study we investigated CR-39 samples irradiated by oxygen ions in a wide range of energy (from 12.64 MeV to 126 MeV). The atomic force microscope used in this study was a TopoMetrix Explorer. We observed almost all of the possible processes on the suface. We found track cores (10-20 nm) surrouned by much larger "berried" halo with diameter of 100-500 nm, corresponding to the electronic collision cascade. We observed roughly 1000 nm long tubes with a diameter 50-100 nm.

Corresponding author: Noemi Rozlosnik, E-mail: noemi@caesar.elte.hu