Real-time gamma dosimetry using PMMA optical fibres for applications in the sterilization industry

The use of polymethylmethacrylate ( PMMA)- based plastic optical fibre as an intrinsic real- time gamma dosimeter is investigated. The radiation- induced attenuation of the fibres is monitored in situ during the course of irradiation. The PMMA fibre exhibited a linear radiation-induced attenuation response at various wavelengths for a dose range of 50 Gy to 50 kGy. The sensitivity, ranging from 0.4 dBm(-1) kGy(-1) to 0.03 dBm(-1) kGy(-1), is wavelength dependent, with high sensitivity at the lower wavelengths.