Radiation sensing is performed through special doped fibres which show a first order (or even linear) increase of the radiation-induced optical attenuation around 1300 to 1500 nm when placed in a radiation field. The temperature dependence of the response is negligible in the envisaged operating range (20 to 90 °C), while the dose-rate dependence was demonstrated to below in a region between 1 and 100 Gy/h.
In order to obtain distributed radiation sensing, the use of a high-resolution Optical Time Domain Reflectometer (OTDR) was attempted. Although the specifications, such as a high spatial resolution, high sensitivity and dynamic range seemed to be ideal for distributed measurements, results obtained were disappointing. Finally, distributed radiation sensing was abandoned for this project.