松山政夫¹⁾、塚田真理¹⁾、奥野健二²⁾、大矢恭久³⁾、相良明男⁴⁾、野田信明⁴⁾、渡辺国昭¹⁾

¹⁾ 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
²⁾ 静岡大学理学部放射化学研究施設、〒422-8592　静岡市大谷836
³⁾ 東京大学アイソトープ総合センター、〒113-0032　東京都文京区弥生2-11-16
⁴⁾ 核融合科学研究所、〒509-5292　土岐市下石町322-6

M. Matsuyama¹⁾, M. Tsukada¹⁾, K. Okuno²⁾, Y. Oya³⁾, A. Sagara⁴⁾, N. Noda⁴⁾, K. Watanabe¹⁾

¹⁾ Hydrogen Isotope Research Center, Toyama University, Gofuku 3190, Toyama 930-8555, Japan
²⁾ Radiochemistry Research Laboratory, Faculty of Science, Shizuoka University, Ohya 836, Shizuoka 422-8529, Japan
³⁾ Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
⁴⁾ National Institute for Fusion Science, Oroshi-cho 322-6, Toki 509-5292, Japan

Abstract

　The effects of helium pre-irradiation on trapping and release behavior of tritium implanted into thin boron films deposited on a plate of stainless steel type S316 were examined by an isothermal heating method and β-ray-induced spectrometry (BIXS). BIXS results showed that the helium pre-irradiation caused an increase in the trapping amount of surface tritium. Isothermal heating of the samples was carried out at temperatures in the range of 473 to 723K, and the decreasing rate of surface tritium was measured by tracking changes in the intensity of X-rays induced by β-rays. It was found that the decreasing rate of residual tritium obeyed first order reaction kinetics, indicating that the helium pre-irradiation has no influence on the tritium release kinetics. Apparent activation energy of the decreasing rate was determined to be 0.3 eV from temperature dependence of the decreasing rate constant, which was about two-times larger than that measured without pre-irradiation of helium.

早川　亮¹⁾，西野雅奈子²⁾，波多野 雄治¹⁾，Vasily Alimov³⁾, Alexander I. Livshits³⁾, 池野進²⁾，中村幸男⁴⁾，大藪修義⁴⁾，渡辺国昭¹⁾

¹⁾ 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
²⁾ 富山大学工学部物質生命システム工学科, 〒930-8555 富山市五福3190
³⁾ Bonch-Bruyevich University of Telecommunications, 61 Moika, St. Petersberg 191186, Russia
⁴) 核融合科学研究所, 〒509-5292 岐阜県土岐市下石町322-6

Ryo Hayakawa¹⁾, Kanako Nishino²⁾, Yuji Hatano¹⁾, Vasily Alimov³⁾, Alexander Livshits³⁾, Susumu Ikeno²⁾, Yukio Nakamura⁴⁾, Nobuyoshi Ohyabu⁴⁾, Kuniaki Watanabe¹⁾

¹⁾ Hydrogen Isotope Research Center, Toyama University, Gofuku 3190, Toyama 930-8555, Japan
²⁾ Department of Material Systems Engineering and Life Science, Faculty of Engineering, Toyama University, Toyama 930-8555, Japan
³⁾ Bonch-Bruyevich University of Telecommunications, 61 Moika, St. Petersberg 191186, Russia
⁴⁾ National Institute for Fusion Science, Oroshi-cho, Toki 509-5292, Japan

Abstract

　Sticking coefficient of H₂, α, on a vanadium surface was measured after heat treatments in vacuum at 673, 873, 973 and 1273 K. The values of α were comparable after heat treatments at 673, 873 and 973 K, while significant reduction was observed after heat treatment at 1273 K. Arrhenius plots of α showed that the pre-exponential factor, α₀, was far smaller than unity for all heat treatment conditions. This observation indicated that only minor portions of surface sites were active for hydrogen ingress. Change in chemical surface state of V by heat treatments in vacuum at 673, 873, 1073 and 1273 K was also investigated by means of X-ray photoelectron spectroscopy. The specimen surface was mainly covered by VO at 673 K and by an oxygen adlayer at 873 K. Sulfur appeared at 1073 K and completely substituted for oxygen at 1273 K. Namely, sulfur became the dominant surface impurity in the temperature region where α showed significant reduction. It was therefore concluded that the barrier effect of oxygen, including formation of a VO layer, was much weaker than that of sulfur under the present conditions.

鳥養祐二1)，村田大樹1)，A. Perevezentsev2)，渡辺国昭1)，松山政夫1)

1) 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
2) EURATOM/UKAEA
Fusion Association, Culham Science Center, Abingdon, OX14 3DB, UK

(author_e)Y. Torikai1), D. Murata1), A. Perevezentsev2), K. Watanabe1), M. Matsuyama1)

(address_e)1) Hydrogen Isotope Research Center, Toyama University, Gofuku 3160, Toyama 930-8555, Japan 2) EURATOM/UKAEA Fusion Association, Culham Science Center, Abingdon, OX14 3DB, UK

Abstract

　Depth profiles of tritium in stainless steel type 316 loaded at several different conditions at JET were analyzed by β-ray-induced X-ray spectrometry (BIXS), in order to investigate the possibilities of the measurement method. The tritium depth profiles obtained by BIXS were compared with that obtained by chemical etching and radioluminography (RLG) methods. It was found that most of tritium depth profiles near surface (up to ≈2μm) obtained by BIXS were in good accordance with chemical etching and RLG methods. In the same time significant difference between BIXS and RLG was found in determination of tritium depth profiles in the sub-surface layer. The reasons for the deviations will be discussed.

北見知士¹⁾，田口　明²⁾，赤丸悟士²⁾，阿部孝之²⁾

¹⁾ 日本ピラー工業株式会社, 669-1333　兵庫県三田市下内神字打場541-1
²⁾ 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

Tomohito Kitami¹⁾, Akira Taguchi²⁾, Satoshi Akamaru²⁾, Takayuki Abe²⁾

¹⁾ Nippon PillarPacking Co., Ltd. 541-1 Utsuba, Shimo Uchigami, Sanda, Hyogo 669-1333
²⁾ Hydrogen Isotope Research Center, Toyama University, Gofuku3190, Toyama 930-8555

Abstract

　Surface coating of bolts and nuts, both of which possess complicated structures, has been successfully carried out by using a barrel-sputtering system. The formed Au film showed good adhesion in a scotch tape test and under the condition of ultrasonic treatment. No pin-hole was observed in examination by SEM which revealed that the surface of the Au film was very smooth, and that the surface configuration of a Au-coated bolt was very similar to that of a bare one. The SEM measurement of the cross-sectional area of a Au-coated nut showed homogeneous coating with a uniform film thickness on not only the external surface but also the screw thread which is in hindered surface. These results indicate that the barrel-sputtering system can be utilized as an alternative to electro- and electroless plating for homogeneous surface coating.

原　正憲¹，赤丸悟士¹，波多野雄治¹，松山政夫¹，柴尾幸伸²，渡辺国昭¹

¹ 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
² アロカ株式会社　金

Masanori HARA¹, Satoshi AKAMARU¹, Yuji HATANO¹, Masao MATSUYAMA¹, Yukinobu SHIBAO², Kuniaki WATANABE¹

¹ Hydrogen Isotope Research Center, Toyama University, Gofuku 3190, Toyama 930-8555, JAPAN
² ALOKA Co., LTD. Kuroda 1-17, Kanazawa, Ishikawa 921-8051, JAPAN

Abstract

　A computer system for dose assessment was installed to evaluate radiation dose of each worker in a controlled area and to automatically produce reports on dose assessment. The main computer was connected to both a tritium monitor control computer and a gate control computer. This computer network has been isolated from a public network. The gate control computer registers data on working hours of each worker in the controlled area and on tritium concentration of each room. The dose assessment computer acquires essential data from the gate control computer to evaluate the radiation dose of each worker. The potential of the specialized network system to improve dose assessment was examined over a period of two years. It was found that this system significantly contributed to improvement of dose assessment. The basis of assessment was made clear, and reports on dose assessment without errors were readily produced.

赤丸悟士，原　正憲，松山政夫，渡辺国昭

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 Akamaru, Masanori Hara, Masao Matsuyama, Kuniaki Watanabe

Hydrogen Isotope Research Center, Toyama University, Gofuku 3190, Toyama 930-8555, Japan

Abstract

　Elemental tritium of 3.7x10₁₂ Bq (100 Ci) was loaded into the Tritium Experimental System for 100 Ci/run in the Hydrogen Isotope Research Center. Tritium gas loaded a stainless steel cylinder, which was purchased from American Radiolabeled Chemical Inc., was transferred to a tritium storage getter in the system. Tritium leakage in a glove box was not observed during the gas transfer operation, indicating that tritium handling could be carried out in safe. The tritium storage getter almost absorbed the gas in the cylinder. Analysis of the quadrapole mass spectrum showed that the residual gas mainly contained tritiated hydrocarbons, ³He and only a small amount of elemental tritium. Analysis of the gas absorbed into the getter was also performed. The volume of absorbed gas corresponded approximately to that of 100 Ci elemental tritium gas, but radioactivity measured by BIXS was only about 80 Ci.