Study on fundamental properties of a PSF detector by using Monte Carlo simulation

Plastic Scintillation Fiber(PSF) detector is used in Fukushima for the measurement of contamination level after the accident of the Fukushima Dai-ichi NPP (2011). By using this device, it is possible to grasp the one-dimensional counting rate distribution of the radiation quickly. But, the accuracy of such measurements has not been examined yet in detail. The purpose of the present work is to study fundamental properties of a PSF detector by using Monte Carlo Simulation. We generated uniform random-number by FORTRAN language and simulated the incident time, the incident position on PSF and the radioactivity strength (i.e. injection rate to PSF). As a result, it was found that the detection efficiency of PSF varied with the change of incident position and incident rate in a radiation field. From the above result, it seems that it is necessary to take account of the position dependence of the detection efficiency for the measurement in high radiation fields as well as the incident-rate dependence. (author)