Detection of high Z (>20) trace elements in calcareous biological materials by PIXE using a Si(Li) detector requires suppression of pile-up due to high intensity Ca and P X-rays. These X-rays may be attenuated evenly by pinhole. Data processing will be straightforward if the filter material is uniform in thickness and if the dimensions of the hole are well-known. However, trying this approach, numerous minuscule punctures and pits in the aluminium foils to start from were detected by STIM microanalysis. Instead of pursuing an ideal filter, a non-ideal aluminium pinhole filter was calibrated for further use. A model was drawn-up and the required parameters were determined, including Si(Li) crystal depth, solid angle, beam energy and an STIM area mass density map.
|Tijdschrift||Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms|
|Status||Gepubliceerd - 2000|