Measurement of Spatial Dose-Rate Distribution Using Scintillating Optical Fiber

Abstract

  In order to measure spatial gamma dose-equivalent-rate distribution at radiation fields in nuclear facilities, a measuring method applying the time-of-flight (TOF) method for a detector using plastic scintillation fibers (PSFs) has been studied. The detector is consisted of a PSF bundle attached photomultiplier tubes at the both ends of it, and two directional photons of scintillation light emitted at the incident position of radiation are sent to the TOF equipment. The position resolution, which was obtained by exposing collimated gamma-rays, was about 30 cm for FWHM. The sensitivity of this detector was about 0.33 cps／μSv/h•cm, and it can be measure for gamma rays up to 10 mSv/h and at energy range from 514 keV to 1400 keV. It was found that the unfolding method developed was much effective to evaluate spatial distribution of gamma dose-equivalent-rate.