Characterisation of radioluminesence based optical fibre dosimeter in radiotherapy beam applications

A PMMA (polymethyl methacrylate) based plastic optical fibre is coated with radiation sensitive inorganic scintillators that fluoresce when exposed to ionising radiation. The emitted signal penetrates the fibre and propagates along the fibre where it is remotely monitored using a fluorescence spectrometer. The dosimeter is characterised for a range of parameters associated with radiotherapy treatment plans, including field size and dose rate. The results demonstrate good repeatability, with a maximum percentage error of 0.59% and the response is independent of dose rate.