Development of beta ray scanner for imaging foliar uptake of radiocesium

Abstract

Large quantities of radionuclides were released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) into the atmosphere, which then contaminated the soil and vegetation surrounding the FDNPP. The research on radiocesium contamination of agricultural products and wild plants is important. Therefore, we developed a simple beta ray scanner to obtain radiographs of the transport and foliar uptake of radiocesium. This simple beta ray scanner comprised a beta ray detector, a motorized sample stage, a shielding box, and a personal computer. Beta rays released from radiocesium were detected effectively using a plastic scintillator plate coupled to multipixel photon counter devices. The spatial resolving power was approximately 6 mm $\times$ 4 mm (FWHM). In a preliminary experiment, a drop of radiocesium solution was placed on the upper surface of a radish leaf. Time-lapse images of radiocesium in the leaf were obtained by the beta ray scanner. Images of isotope transport in the leaf were successfully obtained with the beta ray scanner. The beta ray scanner will be used in our future research on the mechanism of the foliar uptake of radiocesium.