Morphology and annealing kinetics of ion tracks in minerals

¹ Department of Electronic Materials Engineering, The Australian National University, ACT 0200, Australia
² Department of Geological Sciences, University of Michigan, Ann Arbor, Michigan 48109-1005, USA
³ GSI Helmholtz Centre for Heavy Ion Research 64291 Darmstadt, Germany
⁴ Technische Universität Darmstadt, 64289 Darmstadt, Germany

Abstract

We have studied the morphology and annealing kinetics of ion tracks in Durango apatite using synchrotron small angle X-ray scattering. The non-destructive, artefact-free technique enables us to determine the track radii with a resolution of fractions of a nanometre. The tracks were generated using different heavy ions with energies between 185 MeV and 2.6 GeV. The track morphology is consistent with the formation of long cylindrical amorphous tracks. The annealing kinetics, measured by SAXS in combination with ex situ and in situ annealing experiments, suggests structural relaxation followed by recrystallisation of the damaged material. The measurement methodology shown here provides a new means for in-depth studies of ion-track formation in minerals under a wide variety of geological conditions.