Composition and orientation dependent annealing of ion tracks in apatite - Implications for fission track thermochronology

Abstract

The annealing behaviour of swift heavy-ion tracks in apatite from different origins is studied as a function of their crystallographic orientation and the mineral composition. The tracks were generated by irradiating the apatite samples with 2.3 GeV Bi ions, which have a comparable rate of energy loss to fission tracks in this mineral. The track radius was investigated using synchrotron-based small-angle x-ray scattering (SAXS) combined with ex situ annealing. Results indicate that tracks parallel to the c-axis are initially larger and anneal slower than those perpendicular to the c-axis. Natural variation in the mineral composition shows stronger annealing resistance of ion tracks with high..