On-line evaluation of spatial dose-distribution by using a 15m-long plastic scintillation-fiber detector

A 15m-long plastic scintillation fiber (PSF) detector has been applied to the on-line evaluation of spatial dose-distribution inside radiation facilities. The aim of this study is to realize the real-time measurement system which is not only simple but also reliable for monitoring use. Determination of radiation-incident points was made by the measurement of time difference that two directional signals of the scintillation light reach both ends of the PSF [so called “time-of-flight (TOF) method”]. The PSF used had practically enough sensitivity to detect both fast neutrons and gamma-rays.