Optically stimulated luminescence in fluoride phosphate glass optical fibres for radiation dosimetry

Abstract

A novel approach to distributed radiation dosimetry is presented. Our approach uses optically stimulated luminescence in optical fibres to detect ionising radiation. This system is unique in that the optically stimulated luminescence mechanism occurs within the optical fibre itself, which then guides the resulting optical signal to a detector. Fluoride phosphate glass was identified as a suitable material, showing a strong optically stimulated luminescence response to ionising radiation. Optical fibres were fabricated from this glass and radiation-detection measurements performed. Radiation exposure was performed with a ⁹⁰Sr/⁹⁰Y beta source, optical stimulation was provided by a 532nm, 25mW diode laser. The luminescence signal was isolated using two Corning 7-59 filters and detected with an EMI 9635 QA photomultiplier tube. Detection of optically stimulated luminescence produced within the optical fibres is demonstrated. A relationship is shown between the intensity of the luminescence signal, and the applied radiation exposure. The optical fibres are shown to have a consistent response after repeated radiation exposures of 1380.5 ± 37.2 counts/sec. This demonstrates the capacity of the fibres to provide continuous and real-time detection.