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Morishita, Yuki; Higuchi, Mikio*; Kaneko, Junichi*; Kitagawa, Yuichi*; Akedo, Jun*; Soma, Mitsugu*; Matsui, Hiroaki*
Nuclear Instruments and Methods in Physics Research A, 1057, p.168702_1 - 168702_8, 2023/12
Times Cited Count：0 Percentile：0.02(Instruments & Instrumentation)This paper describes the development of a large-area imaging detector capable of measuring the detailed distribution of alpha particles on hands and feet for use in entry/exit control monitors in decommissioning sites such as the Fukushima Daiichi Nuclear Power Plant. The detector was developed using a commercially available ZnS(Ag) scintillator and an electron multiplying CCD camera. The effectiveness of the detector was evaluated by measuring several types of radiation sources, and the results showed that it was possible to detect the position of alpha particles in a very short time, and contamination levels of up to 11 Bq/cm
could be visualized. As a result of the minimal detectable surface activity concentration evaluations, 2.0 minutes or more is required to achieve 4 Bq/cm, and 25.0 minutes or more is required to achieve 0.4 Bq/cm. The field of view of the detector was also checked, and it was confirmed that the setup had a field of view that could cover most of the hand and the sole of the shoe. This detector is expected to be useful for preventing internal uptake and decontamination.
Belik, A. A.*; Iikubo, Satoshi; Yokosawa, Tadahiro*; Kodama, Katsuaki; Igawa, Naoki; Shamoto, Shinichi; Azuma, Masaki*; Takano, Mikio*; Kimoto, Koji*; Matsui, Yoshio*; et al.
Journal of the American Chemical Society, 129(4), p.971 - 977, 2007/01
Times Cited Count：182 Percentile：95.3(Chemistry, Multidisciplinary)Structural properties of polycrystalline single-phased BiMnO samples prepared at 6 GPa and 1383 K have been studied by selected area electron diffraction (SAED), convergent beam electron diffraction (CBED), and the Rietveld method using neutron diffraction data measured at 300 and 550 K. The SAED and CBED data showed that BiMnO crystallizes in the centrosymmetric space group C2/c at 300 K. The analysis of Mn-O bond lengths suggested that the orbital order present in BiMnO at 300 K melts above T= 474 K. The phase transition at 474 K is of the first order and accompanied by a jump of magnetization and small changes of the effective magnetic moment and Weiss temperature.
NbS
Guo, F. Z.*; Matsushita, Tomohiro*; Kobayashi, Keisuke*; Matsui, Fumihiko*; Kato, Yukako*; Daimon, Hiroshi*; Koyano, Mikio*; Yamamura, Yasuhisa*; Tsuji, Toshihide*; Saito, Yuji
Journal of Applied Physics, 99(2), p.024907_1 - 024907_3, 2006/01
Times Cited Count：8 Percentile：31.28(Physics, Applied)Stereoatomscope was used to study the atomic arrangements of intercalation compound FeNbS. The three-dimensional atomic arrangements around different kinds of atoms (Nb and Fe) are visualized by taking the photoelectron angular distribution (PEAD) patterns at clockwise and counterclockwise circularly polarized lights. Atomic distances between the emitters and the scatterers are obtained from the PEAD patterns by measuring the rotation angles of the forward focusing peaks. The applications of stereoatomscope to intercalation compound show the possibility to build an ultimate microscope for scientist.
Nomoto, Kosuke*; Matsui, Mikio*; Inoue, Hiroyuki*; Yoshino, Naoto; Karasaki, Kenji*; Ito, Kazumasa*
JNC TJ8400 2005-005, 94 Pages, 2005/02
JNC-TJ8400-2005-005.pdf:7.92MB
In the safety assessment at geological disposal of High Level Nuclear Waste, it is necessary to understand several properties like hydrological, geological and chemical properties of the disposal site by site investigations. The investigation results should project to the ground water flow modeling, migration modeling and the parameter assignment of these models. Japan Nuclear cycle Development Institute is going to carry out two Underground Research Laboratory plans in order to push on with the project and help to make up the safety criteria of the geological disposal. Horonobe is one area of these plans. In Horonobe, following properties were identified./-There are saline and fresh water./-There is dissolved gas in the underground water./-The underground of some area has high water pressure./In this study, the analysis considering above properties were carried out for understanding of hydrological properties in sedimentary rock. In addition, the affection to the water flow and migration influenced by the results were examined.
Yoshino, Naoto; Nomoto, Kosuke*; Matsui, Mikio*; Nashimoto, Yutaka*
JNC TJ8400 2004-035, 227 Pages, 2005/01
JNC-TJ8400-2004-035.pdf:23.11MB
There are various uncertainty factors in the safety assessment for the geological disposal of High Level Nuclear Waste. And it is difficult to eliminate these uncertainty factors completely. Then it is important to evaluate the various uncertainty factors quantitatively for the safety assessment of the geological disposal. Japan Nuclear Cycle Development Institute focused on the groundwater flow analysis and studied about following issues in 2003 in order to quantify the variance of values which obtained by field investigation or numerical analysis. (1)The method to estimate the hydraulic conductivity and quantify the variability of estimated hydraulic conductivity. (2)The quantification of the key parameter's variability based on probability flow rate analysis. (3)Case study by the vertical two dimensional field. Two-dimensional numerical simulation program in which the uncertainty of the reach point in the ground water flow can be estimated was developed in above subjects. In this study, following three issues are studied (1)verification about the variance of the reach point estimated by 2-dimensional simulation program (2)development of 3-dimensional simulation program (3)Case study by 3-dimensional simulation program
Yoshino, Naoto; Nashimoto, Yutaka*; Matsui, Mikio*; Ito, Setsuo*; Nomoto, Kosuke*
JNC TJ8400 2003-071, 63 Pages, 2004/01
JNC-TJ8400-2003-071.pdf:43.22MB
In this paper authors focused on the uncertainty of the groundwater modeling, and following three issues are examined in order to estimate the spatial variance in the modeling field quantitatively; 1.The method to estimate the hydraulic conductivity and quantify the variability of estimated hydraulic conductivity. 2.The quantification of the key parameter's variability based on probability flow rate analysis. 3.Case study by the vertical two dimensional field.
Noguchi, Hiroshi; Murata, Mikio; Matsui, Hiroshi
7th Int. Congress of the IRPA, Radiation Protection Practice, Vol. 2, p.702 - 705, 1988/00
no abstracts in English
Morishita, Yuki; Higuchi, Mikio*; Kaneko, Junichi*; Kitagawa, Yuichi*; Akedo, Jun*; Soma, Mitsugu*; Matsui, Hiroaki*
no journal, ,
This paper describes the development of a large-area imaging detector capable of measuring the detailed distribution of alpha particles on hands and feet for use in entry/exit control monitors in decommissioning sites such as the Fukushima Daiichi Nuclear Power Plant. The detector was developed using a commercially available ZnS(Ag) scintillator and an electron multiplying CCD camera. The effectiveness of the detector was evaluated by measuring several types of radiation sources, and the results showed that it was possible to detect the position of alpha particles in a very short time, and contamination levels of up to 11 Bq/cm could be visualized. The field of view of the detector was also checked, and it was confirmed that the setup had a field of view that could cover most of the hand and the sole of the shoe. This detector is expected to be useful for preventing internal uptake and decontamination.
