Optical fibre sensor for the online monitoring of gamma radiation doses

The radiation-induced attenuation in poly-methylmethacrylate (PMMA) based plastic optical fibres is monitored online during exposure to gamma radiation, in an investigation in to their use as an intrinsic real-time gamma radiation dosimeter. The PMMA fibre exhibited a linear radiation-induced attenuation response at various wavelengths for a dose range of 50Gy to 50kGy. The sensitivity, ranging from 0.4 dBm- 1/kGy to 0.03 dBm-1/kGy, is wavelength dependant, with higher sensitivity at the lower wavelengths.