Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Terasaka, Yuta; Watanabe, Kenichi*; Uritani, Akira*
Nuclear Instruments and Methods in Physics Research A, 996, p.165151_1 - 165151_8, 2021/04
Times Cited Count：3 Percentile：45.55(Instruments & Instrumentation)For the measurement of radiation distribution inside the Fukushima Daiichi Nuclear Power Station (FDNPS) buildings, the evaluation of a small-diameter quartz optical fiber as a one-dimensional position-sensitive sensor was conducted. The sensor determines the incident position of radiation into the fiber using the time-of-flight information of emitted Cerenkov photons in the optical fiber. Compared with the conventional sensor using the plastic scintillating fiber, the quartz optical fiber has much higher position resolution, which may be the result of the improvement of timing characteristics caused by the prompt emission mechanism of the Cerenkov radiation. Additionally, the response of position-sensitive quartz optical fiber sensor under high radiation field was evaluated, and good count rate linearity was confirmed using the 10 m long quartz optical fiber with a diameter of 0.4 mm up to the dose rate at least 20 mSv/h, and the radiation tolerance property up to the accumulated dose of 1 kGy was evaluated.
Yuguchi, Takashi*; Ogita, Yasuhiro; Kato, Takenori*; Yokota, Rintaro*; Sasao, Eiji; Nishiyama, Tadao*
Journal of Asian Earth Sciences, 192, p.104289_1 - 104289_16, 2020/05
Times Cited Count：5 Percentile：31.49(Geosciences, Multidisciplinary)Quartz from a granitic pluton is found to have formed through sequential growth events under different mechanisms and crystallization temperatures, which can provide new insights into magmatic processes of granitic magmas that were eventually consolidified into plutons. The events were identified using (1) the description of crystal shape and occurrence, (2) the study of the internal structure with cathodoluminescence (CL), and (3) derivation of the crystallization temperatures based on TitaniQ thermometry. The magmatic quartz crystals from the Toki granite, central Japan, are characterized as having the following internal structures: oscillatory zonation, no-oscillatory zonation with luminescence graduation (gradational zonation), and heterogeneous CL. The quartz crystals with oscillatory zonation were formed in the temperature range of about 800 
C to below 700 C, which is referred to as oscillatory zoning temperature (OZT) conditions. The CL zonation pattern was controlled by the temperature conditions and titanium diffusivity in the melt (magma). The crystallization process of quartz within the Toki granite reveals the cooling processes of the granitic pluton; the lithofacies with a high frequency of oscillatory-zoned quartz underwent slower cooling under the OZT conditions than those in other lithofacies.
Takeuchi, Tomoaki; Shibata, Hiroshi; Hanakawa, Hiroki; Uehara, Toshiaki*; Ueno, Shunji*; Tsuchiya, Kunihiko; Kumahara, Hajime*; Shibagaki, Taro*; Komanome, Hirohisa*
JAEA-Technology 2017-026, 26 Pages, 2018/02
JAEA-Technology-2017-026.pdf:4.0MB
Under severe accidents, high-integrity transmission techniques are necessary so as to monitor the situation of the nuclear power plant. In this study, effects of gamma irradiation up to 10
Gy on properties of optical devices were evaluated toward the development of a radiation-resistant in-water wireless transmission system using visible light. After the irradiation, for the LEDs, the total luminous flux decreased and the browning of resin lenses occurred. Meanwhile, the current-voltage characteristics hardly changed. For the PDs, the light sensitivity decreased and the browning of resin window occurred. The dark currents of PDs did not become large enough to adversely affect transmission. These results indicated that both the decreases of the total luminous flux of the LEDs and the light sensitivity of the PDs were mainly caused by not the degradation of the semiconductor parts but the browning of the resin parts by the irradiation. In addition, basic decrease behaviors of light transmission of several different types of glasses by gamma irradiation were also obtained so as to select the suitable optical windows and filters for the developing radiation-resistant in-water wireless transmission system.
Tokuyasu, Kayoko; Yasue, Kenichi; Komatsu, Tetsuya; Tamura, Itoko; Horiuchi, Yasuharu
QST-M-2; QST Takasaki Annual Report 2015, P. 189, 2017/03
Understanding the stage of mountain building is crucial to the stability assessment of geological environments in geological disposal system. In this context, we have carried out the research and development of provenance analysis techniques to elucidate the mountain-building stage. Here we present the results focusing on the R&D using the Electron Spin Resonance (ESR) signals from quartz in sediments and their basement rocks.
JNC TN8400 2001-008, 36 Pages, 2001/03
JNC-TN8400-2001-008.pdf:2.92MB
Research on geologic disposal of high-level radioactive waste(HLW) has been underway in many countries. Bentonite exhibiting a low permeability, high swelling property and high sorption capacity for many radioelements is proposed as a buffer material in many countlies. Recently, cementitious materials are considered as candidate matelials for the geologic disposal of high-level radioactive waste. As the pH and the Ca, Na, K contents of hyperalkaline pore water from the cementitious materials are high, this hyperalkaline pore water would alter the buffer material. The main aim of this study is to investigate the effect of alkaline pore water into the bentonite. Used materials are montmorillonite, albite and quartz composing bentonite. These minerals mixed in a constant ratio (1:1wt%) made to react to distilled water and the alkali solutions (pH11-13). These studies have been conducted at temperatures of 50 - 150C and run times of 10 - 200 day. XRD(X-ray powder diffraction) and SEM (Scanning Electron Microscopy) analyses were applied to studying the structure and quantitative data of each sample. From the result of this study, the main formed mineral of this experiment was analcime, which showed the tendency with a large amount of generation at a higher pH and temperature. Quantitative data of this study was conducted by X-ray powder diffraction method. THe order of the amount of the second analcime in each experiment is shown in the following. Montmorillonite and albite mixing test 
Montmorillonite test Montmorillonite and quartz mixing test Activation energies (E
) using the quantitative data of each test are shown in the following. (1)Montmorillonite test : 54.9kJ/mol (2)Montmorillonite and albite mixing test : 51.9kJ/mol (3)Montmorillonite and quartz mixing test : 59.6kJ/mol
*; Takahashi, Nao*
JNC TJ7440 2000-014, 40 Pages, 2000/02
JNC-TJ7440-2000-014.pdf:17.73MB
no abstracts in English
Sato, Tsutomu; Yanase, Nobuyuki; I.S.Williams*; W.Compston*; M.Zaw*; T.E.Payne*; P.L.Airey*
Radiochimica Acta, 82, p.335 - 340, 1998/00
no abstracts in English
*; Oyama, Yukio; *; Maekawa, Fujio; *; Takahashi, Akito*; Ikeda, Yujiro
Fusion Technology 1996, 0, p.857 - 860, 1996/00
no abstracts in English
Tanaka, Tadao; Onuki, Toshihiko
Geochemical Journal, 28(5), p.369 - 376, 1994/00
Times Cited Count：5 Percentile：15.93(Geochemistry & Geophysics)no abstracts in English
probed by positron annihilationUedono, Akira*; *; *; Ito, Hisayoshi
Journal of Physics; Condensed Matter, 6, p.8669 - 8677, 1994/00
Times Cited Count：26 Percentile：81.18(Physics, Condensed Matter)no abstracts in English
Suzuki, Atsuyuki*; Nagasaki, Shinya*
PNC TJ1602 92-001, 75 Pages, 1992/03
For the safety assessment of high level waste disposal system, it is important to understand the migration behaviors of actinides in the near- or far-field. Although the importance of migration of actinides which form the colloids has been pointed out recently, the migration behaviors of colloids are not fully understood. In this study, the migration behaviors of colloids were investigated experimentally by column method. In the experiments, quartz powder was used as the solid. Ferric hydrous oxide colloids were prepared as the real colloids and neptunium(V) formed Np(V)-Fe(III) pseudocolloids by sorption. Some fractions of the colloids eluted with the eluting solution. Also observed were strongly retarded fractions. Non-negligible fractions were found to migrate faster than the eluting solution. These migration characteristics were qualitatively understood in this work.
Yonezawa, Chushiro; Hoshi, Michio
Bunseki Kagaku, 39, p.25 - 31, 1990/00
no abstracts in English
Morita, Yosuke; Kawakami, Waichiro
IEEE Transactions on Nuclear Science, 36(1), p.584 - 590, 1989/02
Times Cited Count：32 Percentile：93.52(Engineering, Electrical & Electronic)no abstracts in English
Sasaki, Yuji; *; *; *; *
Chikyu Kagaku, 23, p.97 - 103, 1989/00
no abstracts in English
Morita, Yosuke; Kawakami, Waichiro
EIM-87-11, p.87 - 98, 1986/00
no abstracts in English
Hirao, Toshio; Morita, Yosuke; Kawakami, Waichiro
EIM-87-12, p.99 - 109, 1986/00
no abstracts in English
; *
Oyo Butsuri, 55(3), p.248 - 252, 1986/00
no abstracts in English
