Development of a PSF-detector for contaminated areas

Abstract

Hitachi-GE Nuclear Energy, Ltd. has developed the Dose rate meter called "D-phod (Detector for photon dose)" using fiber optics as a radiation sensor to figure out the dose rate of Fukushima area which is contaminated by radioactive materials. D-phod is a tool that can rapidly measure linear or curved dose rate up to 20m along fiber optics. Element technology has already established, however, existing measurement system is unfit to measure environmental dose rate. Therefore, we improved it to be able to be used as a survey meter and completed D-phod. It enables to measure a wide range of environment reasonably. In this paper, we report the development of D-phod which solved the problems mentioned above and can be put into practical use.

Forest type effects on the retention of radiocesium in organic layers of forest ecosystems affected by the Fukushima nuclear accident

“…This system consists of a 10-m-long PSF that responds to gamma radiation, light detection units connected to both sides of the PSF, a signal processing unit, and other components50. The system can provide numerical values of the gamma-ray dose rate in air along the 10-m-long PSF at an interval of 0.5 m.…”

High-Spatial-Resolution Position-Sensitive Plastic Scintillation Optical Fiber Bundle Detector

“…There are a few methods for estimating the gamma-ray source position using the PSOF detector by measuring the time difference, height of pulse, or light power difference in the transmitted path of scintillation light. Using the time difference method, many researchers estimated the position of a gamma ray with FWHMs that were in the range of 3.29-9.12% of the total length of the PSOF [4,15,16,[18][19][20][21][22]. Other researchers used the difference in signal height to estimate the positions of gamma-ray sources.…”

“…Soramoto et al [15], Emoto et al [18], Nohtomi et al [19], Chichester et al [20], and Gamo et al [21] estimated the position of the gamma-ray source using the time difference method. Previous experimental results for spatial resolution showed that the FWHMs were in the range of 3.29-9.12% of the total length of the PSOF.…”