This book describes the suitability of doped SiO2 fibres as ionizing radiation dosimeters. The physical characters of the amorphous medium are discussed, as is the origin of the thermoluminescence (TL) signal and desirable characteristics of such a dosimeter. The present work have established procedures and methodology for characterizing the TL yield of doped silica fibres, irradiated by a comprehensive range of sources, from low energy photons to megavoltages, through to neutrons and charged particles (from beta-sources, accelerated electrons and alpha-particles). Accelerator technology has been utilized, both in terms of elemental analysis (using PIXE and RBS studies), through to ion implantation of oxygen ions. The various TL media (Ge-doped, Al-doped, O2-doped, pure silica, TLD-700 and TLD-100 chips and rods) have been investigated. In terms of their TL parameters (dose response i.e. TL yield and sensitivity for various radiations, as above, energy response, mass dependence, TL glow curve, fading, reproducibility, effective atomic number and minimum detectable dose).