Fiber-optic Multipoint Radiation Sensing System using Waveguide Scintillators

Abstract

Novel fiber-optic radiation sensors and a multipoint measurement method that takes advantage of them have been developed. The new sensor design, which we call a “waveguide scintillator”, consists of a scintillating material and a wavelength-shifting fiber (WLSF). The WLSF is embedded in the scintillating material, and each end is connected to a transparent optical fiber. These waveguide scintillators can be connected in series along an optical fiber loop to form a radiation monitoring system, and each end of the fiber loop is terminated with a photodetector. This new radiation monitoring arrangement dispenses with the need for electronic apparatus at each measuring point and consequently improves resistance to noise. Furthermore, it offers the advantages of multipoint monitoring—meaning that radiation intensity can be measured at multiple sensors—using only two photodetectors. We have examined the light output characteristics and time resolution of a prototype arrangement of these new waveguide scintillators, thus confirming the feasibility of multipoint measurements using a system of multiple waveguide scintillators connected in series in an optical fiber loop.