SAXS study of ion tracks in San Carlos olivine and Durango apatite

Abstract

a b s t r a c tIon tracks were generated in crystalline San Carlos olivine (Mg,Fe) 2 SiO 4 and Durango apatite Ca 10 (PO 4 ) 6 F 2 using different heavy ions ( 58 Ni, 101 Ru, 129 Xe, 197 Au, and 238 U) with energies ranging between 185 MeV and 2.6 GeV. The tracks and their annealing behavior were studied by means of synchrotron based small angle X-ray scattering in combination with in situ annealing. Track radii vary as a function of electronic energy loss but are very similar in both minerals. Furthermore, the annealing behavior of the track radii has been investigated and preliminary results reveal a lower recovery rate of the damaged area in olivine compared with apatite.

SAXS study on the morphology of etched and un-etched ion tracks in apatite

“…From the fits in figure 2, the average latent track radius measured by SAXS for Durango apatite irradiated with 2.3 GeV Bi ions is 5.00±0.08 nm which consistent with the previous studies for apatite [15,16]. On the other hand, for the sample irradiated with 185 MeV, the track radius is 0.5 nm larger with a value of 5.50±0.12 nm which also matches the result reported in [4]. This has been observed previously and explained by the so-called velocity effect [4].…”

“…On the other hand, for the sample irradiated with 185 MeV, the track radius is 0.5 nm larger with a value of 5.50±0.12 nm which also matches the result reported in [4]. This has been observed previously and explained by the so-called velocity effect [4]. The values of electronic energy loss dE/dx for both irradiation conditions calculated from SRIM2008 [17] are 24 keV/nm for 185 Mev Au ions and 29.1 keV/nm for 2.3 Gev Bi ions respectively.…”

“…The strong oscillating scattering intensities yield information about the track radii and indicate monodisperse tracks with a sharp density change between the tracks and matrix material [3,4,11]. As reported in previous studies [3,4,6,12], the most suitable model that fits the scattering intensity from ion tracks in Durango apatite is a cylinder model with a constant density. The solid lines in figure 2 represent the analytical fits to this model.…”

“…Additionally, un-irradiated samples were measured and the scattering signals were used as a reference for background removal. Experimental details for SAXS measurements of ion tracks can be found in references [3,4]. The ion tracks from the samples can be aligned such that the tracks axis is nearly parallel to the x-ray beam.…”

“…At this facility it is also possible to generate ion tracks under high pressure and high temperature conditions. Previous studies in our group focussed on the variations in un-etched track morphology characterised by synchrotron based small angle x-ray scattering (SAXS) [3,4]. SAXS is a non-destructive technique used to study the size, orientation and spatial arrangement of nano-to micro-sized objects.…”