On the registration of low energy (E approximately 1 keV/amu) ion tracks in dielectric minerals

This paper deals with the interaction of low energy (approximately 1 keV/amu), heavy (Z > 10) ions with solid state track detectors. Such ions, losing their energy mainly by nuclear collisions, trigger the formation of very short latent tracks of damaged material showing an enhanced chemical reactivity. Indeed, shallow etch pits have been successfully revealed in muscovite mica etched in 40% hydrofluoric acid. We investigated in detail the variations of these etch pit characteristics with various parameters (atomic number Z and energy E of the incident ions, thermal annealing temperature T). We had in view to extrapolate to such low energies the track model developed by Dartyge et al. at energies >= 1 MeV/amu. Our main results concern (i) the etching of the tracks as a function of Z and E, (ii) the fine structure of the etch pits as a function of Z and (iii) the annealing properties of the tracks. (author)