Measurement of a wide-range of X-ray doses using specialty doped silica fibres

Using six types of tailor-made doped optical fibres, we carry out thermoluminescent (TL) studies of X-rays, investigating the TL yield for doses from 20mGy through to 50Gy. Dosimetric parameters were investigated for nominal 8wt% Ge doped fibres that in two cases were co-doped, using B in one case and Br in the other. A comparative measurement of surface analysis has also been made for non-annealed and annealed capillary fibres, use being made of X-ray Photoelectron Spectroscopy (XPS) analysis. Comparison was made with the conventional TL phosphor LiF in the form of the proprietary product TLD-100, including dose response and glow curves investigated for X-rays generated at 60kVp over a dose range from 2cGy to 50Gy. The energy response of the fibres was also performed for X-rays generated at peak accelerating potentials of 80kVp, 140kVp, 250kVp and 6MV photons for an absorbed dose of 2Gy. Present results show the samples to be suitable for use as TL dosimeters, with good linearity of response and a simple glow curve (simple trap) distribution. It has been established that the TL performance of an irradiated fibre is not only influenced by radiation parameters such as energy, dose-rate and total dose but also the type of fibre. •Nominal 8wt% Ge-doped SiO2 fibre co-doped with B or Br.•The photonic crystal fibre (PCF) collapsed shows the greatest TL response.•TL yield of all fibres show linear response with X-ray dose.•High response tailor-made fibre suitable for use as a TL dosimeter.•XPS shows less hydrocarbon in annealed capillary fibre elevating surface Ge2p3/2.