Abstract
Autoradiography using imaging plates is a conventional method for the visualization of the distribution of radionuclides. Imaging plates have high sensitivity to the charged particles of α- and β-rays but are also sensitive to γ-rays. When the radioactivity level in the sample is low, a longer exposure time is needed, and shielding of the natural background radiation is necessary. Large imaging plates (e.g., 35 × 40 cm), which can obtain the radioactivity distribution over a wider area, were developed. In this work, a low-background shielding box is developed for large imaging plates, and the shielding characteristics of the box and sensitivities of the imaging plate to α-, β-, and γ-rays are quantitatively investigated. It is shown, by considering the sensitivity of imaging plates to α-, β-, and γ-rays, that most images of environmental samples are the result of α- or β-rays emitted from radionuclides at the sample surface, but not from the whole sample. To exemplify autoradiography using the presented shielding box, some environmental samples contaminated with radioactive fallout from the Fukushima Daiichi Nuclear Power Plant accident are measured. The distribution of radionuclides is clearly visualized and, furthermore, information of the migration of radiocesium in the sample is obtained.
Highlights
Many techniques for detecting radiation using scintillators, semiconductors, and position-sensitive detectors were developed
The background count rates (PSL mm−2 ·h−1 ) of the Imaging plates (IPs) were measured in different shielding boxes as a function of the exposure time for up to 48 h
The reduction ratio shows a small difference between 5- and 10-cm-thick lead shielding, mainly as the IP had a higher sensitivity to β-rays than to γ-rays
Summary
Many techniques for detecting radiation using scintillators, semiconductors, and position-sensitive detectors were developed. Saran wrap is charged during unrolling, and the charged film collects radon progenies 214 Pb and 214 Bi, which emanate from concrete walls into the air. The background was measured using Saran wrap and Al foil. The γ-ray peak counts of 214Pb (half-life: 26.8 min) against the elapsed time for Saran wrap film 60Co. Theand γ-ray peak counts of 214. Pbγ-ray (half-life: 26.8room min) against the elapsed for Saran wrap film. Saran wrap filmunrolled was measured unrolled the normalroom experimental room. Shown in Figure and Al foil in the Co γ-ray in irradiation were measured a Ge. Saran wrap filmsunrolled in both rooms showed a reduction of 214Pbroom. Al foil showed an almost constant count rate These results indicate that Saran wrap films collect 214Pb
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
