2.3 Sample preparation for analysis
An aluminum alloy sample holder for 84 samples (Fig. 1) was specifically designed so
that X-ray would travel through it without generating background fluorescence from the
aluminum alloy substrate. To achieve this condition, the sample units were bottomless or
effectively holes at 45° to normal. The sample holder was placed at 45° to the beam and
fluorescence was detected at 90° to the beam. This setup gave an optimal geometry for X-ray
excitation and detection with the lowest scattering background. Uniform filling of the holes with
sample presented a challenge that was resolved by using Kapton® polyimide film to provide a