研究報告

第35巻(2015)

研究報告35 - 1  論文 - Original

LHDプラズマに曝したステンレス鋼の表面変質とヘリウムの吸蔵・放出
Surface Properties and Retention of Helium in Stainless Steel Exposed to LHD Plasmas

吉田直亮1、湯上尚之2、木村陽太2、藤原正1、 荒木邦明1、吉原麗子1、渡邊英雄1、時谷政行3、増崎貴3、波多野雄治4、 松山政夫4、大矢恭久3、奥野健二5
1九州大学応用力学研究所、816-8580 春日市春日公園6-1
2九州大学大学院総合理工学研究科、816-8580 春日市春日公園6-1
3自然科学研究機構核融合科学研究所、509-5292 土岐市下石町322-6
4富山大学研究推進機構水素同位体科学研究センター、930-8555 富山市五福3190
5静岡大学大学院理学領域、422-8529 静岡市駿河区大谷836

N. Yoshida1, N. Yugami2, Y. Kimura2, T. Fujiwara1, K. Araki1, R. Yoshihara1, H. Watanabe1, M. Tokitani3, S. Masuzaki3, Y. Hatano4, M. Matsuyama4, Y. Oya5, K. Okuno5
1Research Institute for Applied Mechanics, Kyushu University, Kasuga-Koen, Kasuga, Fukuoka 816-8580, Japan
2Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-Koen, Kasuga, Fukuoka 816-8580, Japan
3National Institute for Fusion Science, Oroshi, Toki, Gifu 509-5292, Japan
4 Hydrogen Isotope Research Center, Organization for Promotion or Research, University of Toyama, Gofuku, Toyama 930-8555, Japan
5Faculty of Science, Shizuoka University, Ohya, Suruga-ku, Shizuoka 422-8529, Japan

Abstract
Modification of the plasma facing surface of LHD and its effects on the retention and desorption of He were examined by exposing 316L stainless steel coupons to LHD plasmas. In the erosion dominant area, formation of dense He bubbles and mixing of deposited impurities (C, O, Fe, Cr, Ni) occurred in a subsurface region of about 20 nm-thick. In the deposition dominant area, the surface was covered by a porous carbon rich layer. Retention of He was saturated in both areas. In the erosion dominant area, He was trapped by the radiation-induced defects formed in the very thin subsurface region. The concentration of He trapped in the impurity deposition (He/C) in the deposition dominant area was estimated to be 0.9%.

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研究報告35 - 2  論文 - Original

Ptナノ粒子の粒子成長とCO吸着
Growth and CO chemisorption study of platinum nanoparticles on α-Al2O3

田口 明、尾崎 智弘
富山大学 研究推進機構 水素同位体科学研究センター
〒930-8555 富山市五福3190

Akira Taguchi*, Tomohiro Ozaki
Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555, Japan

Abstract
Pt nanoparticles sputter-deposited on α-Al2O3 support were investigated by FE-SEM measurements and CO chemisorption studies. Pt nanoparticles formed in the early stages of sputter deposition were well isolated, and the particle size distribution of Pt nanoparticles evaluated by FE-SEM measurements was narrow. Longer sputter deposition resulted in growth and coalescence of Pt nanoparticles. Such a transition of Pt from nanoparticles to film by sputter deposition was properly evaluated by CO chemisorption studies.

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研究報告35 - 3  論文 - Original

放射性汚染水の減容化に対する氷結晶法の適用性
Applicability of Freezing Technique for Volume Reduction of Waste Water Contaminated with Radioactive Materials

松山 政夫a,*、阿部 信介a、対馬 勝年b
a富山大学 研究推進機構 水素同位体科学研究センター
b富山大学 理学部
〒930-8555 富山市五福3190

Masao Matsuyamaa,*, Shinsuke Abea, and Katsutoshi Tusimab
aHydrogen Isotope Research Center, Organization for Promotion of Research, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan
bFaculty of Science, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan

Abstract
The applicability of a freezing technique to the reduction of the volume of waste water contaminated with radioactive materials such as 137Cs, 90Sr, and 90Y has been examined. Simulated waste water containing a trace amount of added non-radioactive cesium (ca. 20 wt. ppm) was used in this study. A cooling pipe was immersed in the simulated waste water, and the cesium concentration in the ice produced around the pipe and the residual water were measured by an atomic absorption spectrometry after a given time. The temperature of the cooling fluid flowed through the pipe was regulated below 273 K using a conventional cooling device. The cesium concentration in the formed ice was found to be more 200 times lower than that in the initial simulated waste water. The same results were obtained for waste water with added radioactive cesium (137Cs), and similar phenomena observed for simulated water containing strontium, yttrium, and NaCl with cesium. It was suggested that the cesium concentration is strongly affected by the number of bubbles in the ice, crystal size of the ice, and the total impurity concentration in the waste water. Our results indicate that freezing is a promising candidate technique for the processing of radioactive waste water.

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研究報告35 - 4  論文 - Original

液体シンチレーションカウンタにおける波高スペクトルへの化学クエンチングの影響
Effect of chemical quenching on pulse height spectrum in liquid scintillation counter

原 正憲a,*,中野 史菜a,阿部 信介a,中山 将人a
a富山大学水素同位体科学研究センター、〒930-8555 富山市五福3190

Masanori HARAa,*, Fumina NAKANOa, Shinsuke ABEa, Masato NAKAYAMAa
aHydrogen Isotope Research Center, University of Toyama, Toyama 930-8555, Japan

Abstract
In liquid scintillation counting, quenching correction of the sample is indispensable for measuring radioactivity. The chemical quenching is corrected by a quenching correction curve obtained with a quenched standard set. In this work, the applicability of a quenched standard set to various chemical substances was studied using angle distributions in 2D scintillation spectra. The quenching dependence of the angle distributions measured from various chemical quenchers was found to coincide. Namely, the relationship between the chemical quenching and the angle distribution is maintained whatever chemical substances is used. This result indicates that a single quenched standard can be used to correct for the effect of various chemical quenchers.

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研究報告35 - 5  論文 - Original

多角バレルスパッタリング装置を用いたオキシ窒化リン酸リチウム(LiPON)電解質調製
Preparation of Lithium Phosphorus Oxynitride (LiPON) Electrolytes Using the Polygonal Barrel-Sputtering System

西澤 秀基、井上 光浩、阿部 孝之
富山大学研究推進機構水素同位体科学研究センター 〒930-8555富山市五福3190

Hideki Nishizawa, Mitsuhiro Inoue, Takayuki Abe
Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555, Japan


Abstract
Lithium phosphorous oxynitride (LiPON) electrolytes for solid-state lithium batteries were prepared using the polygonal barrel-sputtering system. When sputtering was carried out at an N2 gas pressure of 4 Pa and an AC power of 100 W for 120 min using a Li3PO4 target plate, a worm-like deposition was formed on the planer silicon substrate. An N1s peak was observed at around 400 eV in the X-ray photoelectron spectroscopy survey spectrum of the sputtered sample. This N1s peak was deconvoluted into two peaks: one at 397.4 eV ascribed to P-N<P bond formation and the other at 399.0 eV reflecting P-N=P bond formation. Based on these data, the formed deposit was assigned to LiPON. The ion conductivity of the prepared LiPON was evaluated by impedance measurements. A semicircle was obtained in the Cole-Cole plot, from which the ion conductivity was determined to be 1.8 × 10-6 S cm-2, close to those of typical LiPON films in the literature (1.7 × 10-6-6.4 × 10-6 S cm-2). Thus, LiPON films can be prepared by the polygonal barrel-sputtering system.

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研究報告35 - 6  ノート - Note

電気抵抗測定から見た酸素存在下でのPdの水素吸収・放出挙動
Hydrogen absorption-desorption behaviors on Pd in the presence of oxygen evaluated by electrical resistance measurements with NIM components

赤丸悟士a,*、古里咲輝a、原 正憲a、松山政夫a
富山大学水素同位体科学研究センター、930-8555富山市五福3190

Satoshi Akamaruaa,*, Saki Furusatoa, Masanori Haraa, Masao Matsuyamaa
Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555, Japan


Abstract

To understand the hydrogen absorption and desorption behaviors of Pd under air, we performed real time measurements of the electrical resistance of Pd under gas mixture with various oxygen contents. The hydrogen absorption rate was independent of oxygen concentration. Conversely, the hydrogen desorption rate in the presence of oxygen was faster than that without oxygen, suggesting that the additional desorption path including water formation reaction appears in the hydrogen desorption process in the presence of oxygen. The hydrogen concentration in Pd at equilibrium decreased with increasing oxygen concentration in gas phase because the hydrogen adsorption sites become partially occupied by oxygen atoms.

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