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Irradiation parameters and track radii extracted from SAXS measurements. Table 1 is nearly parallel to the X-ray beam. Tilting the sample by 10°, for example, results in highly anisotropic scattering in the form of narrow streaks that are shown in Fig. 1(b) and (d). This anisot- ropy results from the high aspect ratio of the ion tracks, which are only a few nanometers wide and up to tens of micrometers long. X-ray intensities of radial sectors perpendicular to the streaks in the anisotropic images resemble those of unirradiated samples. This suggests the lack of significant density fluctuations on the nanometer length scale along the ion tracks. Transmission SAXS measurements were performed at the SAXS/ WAXS beamline at the Australian Synchrotron with an X-ray energy of 12keV and a camera length of approximately 1600 mm. Mounting the samples on a three-axis goniometer allowed for precise alignment of the ion tracks with respect to the X-ray beam. Measurements were taken with the ion tracks tilted by 0°, 5° and 10° with respect to the X-ray beam and spectra were collected with a Pilatus 1 M detector with exposure times of 5 and 10s. Scattering from un-irradiated samples was measured for background removal and the absolute scattering was calibrated using a glassy carbon standard [21].

Table 1 Irradiation parameters and track radii extracted from SAXS measurements. Table 1 is nearly parallel to the X-ray beam. Tilting the sample by 10°, for example, results in highly anisotropic scattering in the form of narrow streaks that are shown in Fig. 1(b) and (d). This anisot- ropy results from the high aspect ratio of the ion tracks, which are only a few nanometers wide and up to tens of micrometers long. X-ray intensities of radial sectors perpendicular to the streaks in the anisotropic images resemble those of unirradiated samples. This suggests the lack of significant density fluctuations on the nanometer length scale along the ion tracks. Transmission SAXS measurements were performed at the SAXS/ WAXS beamline at the Australian Synchrotron with an X-ray energy of 12keV and a camera length of approximately 1600 mm. Mounting the samples on a three-axis goniometer allowed for precise alignment of the ion tracks with respect to the X-ray beam. Measurements were taken with the ion tracks tilted by 0°, 5° and 10° with respect to the X-ray beam and spectra were collected with a Pilatus 1 M detector with exposure times of 5 and 10s. Scattering from un-irradiated samples was measured for background removal and the absolute scattering was calibrated using a glassy carbon standard [21].

Related Figures (5)

Fig. 1. Scattering image of samples irradiated with 2.2 GeV Au ions (a) olivine with the X-ray beam parallel to the ion tracks, (b) with the tracks tilted by ~10°, (c) apatite w: the X-ray beam parallel to the ion tracks, (d) with the tracks tilted by ~10°. Fig. 1(a) and (c) show isotropic scattering images from the ion racks in olivine and apatite, respectively, when the ion track axis where q is the scattering vector, L the length of the track, R the track radius, py the density difference between track and matrix, and J, is the first order Bessel function. A narrow Gaussian distribution of
Fig. 1. Scattering image of samples irradiated with 2.2 GeV Au ions (a) olivine with the X-ray beam parallel to the ion tracks, (b) with the tracks tilted by ~10°, (c) apatite w: the X-ray beam parallel to the ion tracks, (d) with the tracks tilted by ~10°. Fig. 1(a) and (c) show isotropic scattering images from the ion racks in olivine and apatite, respectively, when the ion track axis where q is the scattering vector, L the length of the track, R the track radius, py the density difference between track and matrix, and J, is the first order Bessel function. A narrow Gaussian distribution of
Fig. 2. SAXS scattering intensity from ion tracks in olivine (symbols) and corresponding fits with the hard cylinder model (solid lines) for different irradiation conditions (see Table 1).
Fig. 2. SAXS scattering intensity from ion tracks in olivine (symbols) and corresponding fits with the hard cylinder model (solid lines) for different irradiation conditions (see Table 1).
Fig. 3. Absolute scattering intensities from ion tracks in apatite samples irradiated with 185 MeV Au ions after background removal as a function of scattering vector q. The solid lines are the corresponding fits to the hard cylinder model.
Fig. 3. Absolute scattering intensities from ion tracks in apatite samples irradiated with 185 MeV Au ions after background removal as a function of scattering vector q. The solid lines are the corresponding fits to the hard cylinder model.
Fig. 4. Track radii as a function of electronic energy loss for different irradiation conditions; the solid and dashed lines are to guide the eye. The inset shows the electronic energy loss of Au ions as a function of energy in apatite calculated with SRIM2008. The vertical lines indicate the energy of the two different Au beams used. Absolute calibration of the scattering intensities enables an esti- mation of the density change within the ion tracks in olivine to be about 1 + 0.7% as compared with the crystalline matrix. This value is similar to the density change observed in apatite [19].
Fig. 4. Track radii as a function of electronic energy loss for different irradiation conditions; the solid and dashed lines are to guide the eye. The inset shows the electronic energy loss of Au ions as a function of energy in apatite calculated with SRIM2008. The vertical lines indicate the energy of the two different Au beams used. Absolute calibration of the scattering intensities enables an esti- mation of the density change within the ion tracks in olivine to be about 1 + 0.7% as compared with the crystalline matrix. This value is similar to the density change observed in apatite [19].
Fig. 5. Track radius as a function of annealing time for isothermal in situ annealing at 350°C extracted from the fits for olivine and apatite. Error bars are included in the graph that in some cases are smaller than size of the data point. Dashed lines are to guide the eye.
Fig. 5. Track radius as a function of annealing time for isothermal in situ annealing at 350°C extracted from the fits for olivine and apatite. Error bars are included in the graph that in some cases are smaller than size of the data point. Dashed lines are to guide the eye.
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