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Volume 64, Issue 12
Displaying 1-7 of 7 articles from this issue
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Article
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Naoyuki KANDA, Ying WANG, Noriaki KATAOKA, Ryuta YAMADA, Hiroshi IMAIZ ...2015 Volume 64 Issue 12 Pages 717-728
Published: December 15, 2015
Released on J-STAGE: December 29, 2015
JOURNAL OPEN ACCESSThe Fukushima Daiichi Nuclear Power Plant Accident happened in 12 - 15th March 2011. This accident caused to the radioactive contamination in the near area. In this work, some lake waters and the sediments were collected in Fukushima Prefecture and Niigata City to clarify the effect of the accident on the area contaminated. As to the collected lake water, an enrichment of “the specific activity of tritium(T specific activity)” in each water collected was carried out by the solid polymer electrolyte(SPE) apparatus, and the T specific activity was measured by a liquid scintillation counter. Based on the T specific activity thus measured, the influence of the accident to the environment was investigated. At the same time, specific activities of radioactive caesiums in the lake sediments were also measured. Consequently, the influence of the Fukushima Daiichi Nuclear Power Plant Accident to the adjacent lakes(e.g., in Fukushima Prefecture and Niigata City) was quantitatively clarified. From the above‐mentioned matters, it is found that the effect of the accident on Niigata City is so small, and the accident gradually decreases in Fukishima Prefecture.View full abstractDownload PDF (5773K) -
Xiaosong Xiaosong, Yang TIAN, Kenji SHIMAZOE, Takeshi FUJIWARA, Hiroyu ...2015 Volume 64 Issue 12 Pages 729-735
Published: December 15, 2015
Released on J-STAGE: December 29, 2015
JOURNAL OPEN ACCESSA high-energy X-ray/gamma-ray imaging system based on a hydrogenated amorphous silicon(a-Si:H)/crystalline silicon(c-Si) heterojunction strip detector was developed. The imaging system will be applied in nondestructive testing of concrete structures. We fabricated 50-channel heterojunction strip detectors with a1mm pitch on 500μm thick p-type silicon wafers. The average leakage current was 2.9nA per channel at 120V reverse bias. Energy resolutions of 2.8keV FWHM at 59.5keV and 2.9keV FWHM at 122keV were obtained at 18℃. The position sensitivity of the strip detector was measured by edge-on irradiation with a 137Cs gamma-ray source. Edge-on gamma-ray imaging of a tungsten object using the prototype was performed. A module consisting of 20 stacked silicon strip detectors is being constructed.View full abstractDownload PDF (4165K)
Technical Report
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Takao KAWANO, Yoshiaki ANDO, Yuuichi IZUMI2015 Volume 64 Issue 12 Pages 737-744
Published: December 15, 2015
Released on J-STAGE: December 29, 2015
JOURNAL OPEN ACCESSInstant coffee contains natural potassium-40 and is a very comprehensible educational tool for illustrating naturally existing radiations and radioisotopes because potassium-40 emits radiations. In the present study, a compression and formation method was applied to 10 varieties of commercially available instant coffees and 10 coffee block radiation sources were fabricated. Thus fabricated radiation sources were examined by comparing their dimensions(side length and thickness), weights and radioactivity of 40K. For comparison, radioactivity of 40K contained in 6 varieties of commercially available regular coffees was also measured. It was found that the dimensions and weights of the fabricated radiation sources did not significantly vary by difference of instant coffees, and the average radioactivity of 40K contained in the 10 coffee block radiation sources was 16.6Bq, being about 1.7times more intensive than that of regular coffees.View full abstractDownload PDF (4381K)
Materials(Data)
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Takeshi IIMOTO, Tomohisa KAKEFU, Itaru TAKAHASHI, Rieko TAKAKI2015 Volume 64 Issue 12 Pages 745-752
Published: December 15, 2015
Released on J-STAGE: December 29, 2015
JOURNAL OPEN ACCESSA mission on the development of nuclear science and technology education program for secondary school students in the Asia‐Pacific Ocean area by the IAEA(2012 - 2015 years) is in progress. Attractive educational programs covering fields of science, technology, engineering and mathematics(STEM) have been developed. Selected pilot countries(the Philippines, Malaysia, Indonesia, UAE) use the programs and education tools as their trial under their own circumstances. Background and trends of this activity, Japanese support to the activity, and its future scope are introduced.View full abstractDownload PDF (5463K)
Review Article
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Katsumi HIROSE2015 Volume 64 Issue 12 Pages 753-764
Published: December 15, 2015
Released on J-STAGE: December 29, 2015
JOURNAL OPEN ACCESSFukushima Dai-ichi Nuclear Power Plant(F1NPP) accident, which occurred as a result of huge earthquake and resulting tsunami, had a severe impact on world communities as did Japanese, because of cause of serious radioactivity contamination in the environment. Long-term effects of radioactivity contamination from F1NPP are concerned. To assess the long-term environmental effects of the F1NPP accident, it is important to review the history of global radioactivity contamination, which started from Hiroshima and Nagasaki nuclear explosions in Aug. 1945. Radionuclides released in the environment as a result of atmospheric nuclear explosions, nuclear reactor accident and others are migrated between atmosphere, hydrosphere, biosphere and lithosphere according to natural processes. We describe long-term environmental behaviors of anthropogenic radionuclides derived from the atmospheric nuclear explosions and others, which is useful to predict the behaviors and fate of the F1NPP-derived radionuclides.View full abstractDownload PDF (8264K)
Serial Lectures
Neutron Scattering Study on Dynamics of Atomic and Molecular Motions
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Takatsugu MASUDA2015 Volume 64 Issue 12 Pages 765-774
Published: December 15, 2015
Released on J-STAGE: December 29, 2015
JOURNAL OPEN ACCESSThe enhanced simultaneous order in magnetism and dielectricity, multiferroics, has been extensively studied since the discovery of its experimental realization in the perovskite manganite TbMnO3. Among the multiferroic materials Ba2CoGe2O7 is a rare experimental realization where the electric polarization is represented by spin-nematic operators. We revealed the existence of spin-nematic interaction by combination of magnetization and neutron scattering experiments and we determined the dielectric energy by analyzing neutron scattering spectrum. We propose that the spin-nematic interaction constant can be a performance index of multiferroic device.View full abstractDownload PDF (6229K)
2-D Capturing of Radiations
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Tatsuo TORII2015 Volume 64 Issue 12 Pages 775-782
Published: December 15, 2015
Released on J-STAGE: December 29, 2015
JOURNAL OPEN ACCESSRadioactive materials were diffused in the environment by the accident of the Fukushima Daiichi Nuclear Power Plant, TEPCO. Radiation monitoring from the sky is effective to find the contaminated areas quickly in Fukushima Prefecture, where 70% is occupied by the forests. In this report, it is given an outline about a monitoring technology from the sky using unmanned aerial vehicles and a new measuring technique under development as well as the aerial monitoring using the manned helicopter.View full abstractDownload PDF (5004K)
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