Implementation of Optical-Fiber Postmortem Dose Measurements: A Proof of Concept

We describe the implementation of a versatile system and the corresponding method to perform fast postmortem optical attenuation measurements on irradiated optical-fibers (OFs) for dosimetry purposes. The measurement is based on the radiation-induced attenuation (RIA) phenomenon. We use a dual-wavelength optical time-domain reflectometer (OTDR) coupled with a suitable radiation-sensitive OF. We demonstrate that radiation dose levels higher than 100 Gy(SiO2) can be measured efficiently with 1-m-long samples. The accuracy of the measurement increases with the increasing radiation dose if the length of the sample is kept fixed. We also highlight the possible limitations of our approach and, more generally, limitations related to performing accurate RIA measurement (online or postmortem) on short single-mode (SM) OF samples. The technological solution we propose can be tailored to address different radiation environments.