XPS and PIXE Analysis of Doped Silica Fibre for Radiation Dosimetry

The material characteristics of doped SiO₂ fibre are studied, the electron traps in the product medium creating a situation attractive for their application in thermoluminescence (TL) radiation dosimetry. To date, rather limited research has been conducted towards gaining an essential understanding of the magnitude of TL signal and material characteristics of doped fibres. Characterization is being sought to ensure that the mechanism of TL yield in optical fibres is well understood, allowing a favourable well controlled production situation to be established. The intended end point is to specify dosimeters, not only for clinical dosimetry but also for their application in industrial/energy-industry settings. Investigation of the surface oxidation state of the Ge-doped SiO₂ optical preform has been carried out using the X-ray photoelectron spectroscopy technique. In a further development using the fibre forming technology, particle-induced X-ray emission/Rutherford back scattering measurements have been employed to ascertain dopant concentrations of Ge-doped-cladding photonic crystal fibres (PCFs) with a view to improving TL yield. Present results concern uncollapsed and collapsed-hole-PCFs.