Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
HIDEO WATANABE Last modified date:2022.06.13

Associate Professor / Advanced Energy Engineering Science, High Energy Material Science / Division of Nuclear Fusion Dynamics / Research Institute for Applied Mechanics

1. Katsuhito Takahashi , Tomio Iwasaki, Hideo Watanabe, Kenta Murakami, Effect of zirconium-ion irradiation on properties of secondary phase particles in zirconium-oxide film, Journal of Nuclear Materials, 2021.12.
2. Hideo Watanabe ,Yoshiki Saita ,Katsuhito Takahashi ,Kazufumi Yasunaga, Desorption of Implanted Deuterium in Heavy Ion-Irradiated Zry-2, quantum beam science,, 5(2), 9, 2021.04, To understand the degradation behavior of light water reactor (LWR) fuel-cladding tubes under neutron irradiation, a detailed mechanism of hydrogen pickup related to the point defect formation (i.e., a-component and c-component dislocation loops) and to the dissolution of precipitates must be elucidated. In this study, 3.2 MeV Ni3+ ion irradiation was conducted on Zircaloy-2 samples at room temperature. Thermal desorption spectroscopy is used to evaluate the deuterium desorption with and without Ni3+ ion irradiation. A conventional transmission electron microscope and a spherical aberration-corrected high-resolution analytical electron microscope are used to observe the microstructure. The experimental results indicate that radiation-induced dislocation loops and hydrides form in Zircaloy-2 and act as major trapping sites at lower (400–600 °C) and higher (700–900 °C)-temperature regions, respectively. These results show that the detailed microstructural changes related to the hydrogen pickup at the defect sinks formed by irradiation are necessary for the degradation of LWR fuel-cladding tubes during operation..
3. Peng Song, Akihiko Kimura, Kiyohiro Yabuuchi, Peng Dou, Hideo Watanabe, Jin Gao, Yen Jui Huang, Assessment of phase stability of oxide particles in different types of 15Cr-ODS ferritic steels under 6.4 MeV Fe ion irradiation at 200 °C, Journal of Nuclear Materials, 10.1016/j.jnucmat.2019.151953, 529, 2020.04, Three types of 15Cr-ODS ferritic steels were irradiated with 6.4 MeV Fe3+ at 200 °C up to a nominal displacement damage of 10 dpa to assess the phase stability of different sorts of oxide particles under ion-irradiation. Before the irradiation, dominant oxide particles in (Y, Ti) ODS, (Y, Al) ODS and (Y, Zr) ODS steels were identified as Y-Ti-O, Y-Al-O, and Y-Zr-O types, respectively, and the difference in the average diameters and number densities of oxide particles among the three ODS ferritic steels was as small as within the factor of two. After the irradiation, the number densities and volume fractions of oxide particles in all the three ODS steels decreased with increasing dpa regardless of the different dispersion morphologies, chemical compositions and crystal structures of the particles, which was interpreted in terms of the dominant mechanism of ballistic dissolution with a moderate occurrence of radiation-enhanced diffusion (RED) and re-precipitation of the nano-clusters. Almost no significant difference in the phase stability of oxide particles was recognized among the three types of ODS ferritic steels. However, normalized volume fractions of Y-Zr-O particles were slightly bigger than those of Y-Ti-O and Y-Al-O at high damage levels. Moreover, Y-Al-O particles underwent the loss of moiré fringe because of the amorphization of oxide particles, while the δ-phase Y4Zr3O12 in (Y, Zr) ODS still maintained crystalline structure even at ∼ 20 dpa/local. It is concluded that Y-Zr-O particles are more stable than Y-Al-O and possibly Y-Ti-O particles..
4. Shiro Entani, Konstantin V. Larionov, Zakhar I. Popov, Masaru Takizawa, Masaki Mizuguchi, Hideo Watanabe, Songtian Li, Hiroshi Naramoto, Pavel B. Sorokin, Seiji Sakai, Non-chemical fluorination of hexagonal boron nitride by high-energy ion irradiation, Nanotechnology, 10.1088/1361-6528/ab5bcc, 31, 12, 2020.01, Two-dimensional materials such as hexagonal boron nitride (h-BN) and graphene have attracted wide attention in nanoelectronics and spintronics. Since their electronic characteristics are strongly affected by the local atomic structure, the heteroatom doping could allow us to tailor the electronic and physical properties of two-dimensional materials. In this study, a non-chemical method of heteroatom doping into h-BN under high-energy ion irradiation was demonstrated for the LiF/h-BN/Cu heterostructure. Spectroscopic analysis of chemical states on the relevant atoms revealed that 6% ± 2% fluorinated h-BN is obtained by the irradiation of 2.4 MeV Cu2+ ions with the fluence up to 1014 ions cm-2. It was shown that the high-energy ion irradiation leads to a single-sided fluorination of h-BN by the formation of the fluorinated sp 3-hybridized BN..
5. Kazuhito Ohsawa, Takeshi Toyama, Yuji Hatano, Masatake Yamaguchi, Hideo Watanabe, Stable structure of hydrogen atoms trapped in tungsten divacancy, Journal of Nuclear Materials, 10.1016/j.jnucmat.2019.151825, 527, 2019.12, Stable structures of hydrogen atoms trapped in a divacancy in tungsten and their binding energies are presented on the basis of first-principle calculations. The hydrogen atoms are favorable sitting in the vicinity of octahedral interstitial sites (O-sites) next to the divacancy. Besides, hydrogen atoms preferentially occupy O-sites located in the center of the divacancy. As hydrogen atoms increases, O-sites located in the periphery of the divacancy are also occupied by the hydrogen atoms. The divacancy in tungsten is energetically unstable, compared with two isolated monovacancies. However, the divacancy is extremely stabilized by the hydrogen atom trapping. The binding energy of the divacancy depends on the sort of the hydrogen isotope..
6. Characterization of interface irradiation damage in Ti-clad V-4Cr-4Ti composite material
7. Jean Marc Costantini, Gérald Lelong, Maxime Guillaumet, Didier Gourier, Seiya Takaki, Norito Ishikawa, Hideo Watanabe, Kazuhiro Yasuda, Optical reflectivity of ion-irradiated cerium dioxide sinters, Journal of Applied Physics, 10.1063/1.5100582, 126, 17, 2019.11, Reflection spectra of cerium dioxide sintered samples were measured in the UV-visible range after irradiation with various heavy ions (2.4-MeV Cu, 5-MeV W, 10-MeV W, 36-MeV W, 100-MeV Kr, and 200-MeV Xe). Differential reflectance spectra of irradiated samples after subtraction of the reference sample spectrum are fit with six broad Gaussian bands centered at about 1.2, 2.2, 2.8, 4.0, 4.8, and 6.2 eV. The growth curves of most bands show a saturation behavior vs ion fluence. Reflection spectra are consistent with the UV-visible absorption spectra of electron-irradiated ceria single crystals for photon energies lower than 3.2 eV, corresponding to the optical gap. The spectra are tentatively analyzed on the basis of charge transfer bands and the 4f-5d transitions related to the Ce3+ ions in the distorted environment formed by irradiation. More insight into defect formation is given by the reflection spectra rather than the absorption ones due to the limitation in the absorption of the optical gap. These data are also discussed with reference to the radiation damage processes by electronic excitations and nuclear collisions in ceria..
8. Moeko Nakata, Keisuke Azuma, Akihiro Togari, Qilai Zhou, Mingzhong Zhao, Takeshi Toyama, Yuji Hatano, Naoaki Yoshida, Hideo Watanabe, Masashi Shimada, Dean Buchenauer, Yasuhisa Oya, Dynamics evaluation of hydrogen isotope behavior in tungsten simulating damage distribution, Fusion Engineering and Design, 10.1016/j.fusengdes.2019.03.114, 146, 2096-2099, 2019.09, 0.8 MeV and 6 MeV iron (Fe) ions were implanted into tungsten (W) to produce the irradiation damages with the various damage distributions. Thereafter, 1.0 keV deuterium ion (D2 +) implantation was performed to evaluate the D retention behavior on damage distribution in W. The experimental results showed that the total D retentions were decreased by increasing the damage concentration introduced near the surface region by 0.8 MeV Fe ion implantation. The retention of D trapped by vacancy clusters and voids, which would be the stable trapping sites with higher trapping energies, were reduced, suggesting that the recombination of D atom into D2 on the W surface was enhanced due to D accumulation near the surface region. It can be said that the hydrogen retention behavior in PFMs will be controlled by the damage distribution near the surface..
9. Jean Marc Costantini, Gaëlle Gutierrez, Hideo Watanabe, Kazuhiro Yasuda, Seiya Takaki, Gérald Lelong, Maxime Guillaumet, William J. Weber, Optical spectroscopy study of modifications induced in cerium dioxide by electron and ion irradiations, Philosophical Magazine, 10.1080/14786435.2019.1599145, 99, 14, 1695-1714, 2019.07, UV-visible absorption spectroscopy and Raman spectroscopy were used to study damage production in cerium dioxide epitaxial films and polycrystalline sintered samples after irradiation with electrons for three energies to span the threshold displacement energies of cerium and oxygen atoms, and 2.4-MeV Cu ions. Neither amorphization nor specific colour-centre bands were detected. Evolutions of the refractive index were derived from the interference fringes in the optical transmission spectra of epilayers after irradiation. No significant change of the refractive index occurred for the 1.0-MeV electron irradiation, whereas a maximum decrease by 28 ± 8% was deduced for the 1.4-MeV and 2.5-MeV energies. These modifications are consistent with ballistic damage on the cerium sublattice for high electron energies producing Ce3+ ions. However, no significant change of refractive index was found for the Cu ion irradiation. This likely stems from the high rate of Frenkel pair recombination in the collision cascades induced by more energetic recoils than for the electron irradiations, combined with electronic excitations and hole capture on Ce3+ ions. This study reveals modifications of the electronic structure upon irradiation that could take place in other non-amorphizable oxide systems..
10. Yun Wang, Hideo Watanabe, Dongyue Chen, Junya Kaneda, Naoto Shigenaka, Effect of Ta addition on irradiation resistance properties of austenitic stainless steels for reactor pressure vessel internals, 27th International Conference on Nuclear Engineering: Nuclear Power Saves the World!, ICONE 2019 Proceedings of the 27th International Conference on Nuclear Engineering, ICONE 2019 - "Nuclear Power Saves the World!", 2019.05, In order to elevate the resistance against irradiation-assisted stress corrosion cracking (IASCC) of reactor pressure vessel internals (RINs) in the environment of boiling water reactor (BWR), austenitic stainless steels (SSs) with tantalum (Ta) addition have been examined. The oversized element Ta is considered to reduce the concentration of free vacancy due to trapping effect. It is expected that radiation-induced grain boundary (GB) segregation of constituent element such as chromium (Cr) can be suppressed by Ta addition. In this study the irradiation tests were performed with Fe2+ ion in a dose range from 0.1 to 3 dpa on the specimens sampled from base materials and heat-affected zone (HAZ) of welding joint plates. Considering the Cr segregation might also occur during the heat history of welding process, we first confirmed and discussed the effect of Ta addition to SUS310S on irradiation resistance properties in the HAZ. The radiation-induced segregation (RIS) on random GBs in HAZ after the irradiation tests was evaluated by scanning transmission electron microscope (STEM) and X-ray energy dispersive spectroscopy (XEDS). The improvement of resistance against RIS by Ta addition was evaluated. Further the effect of Ta addition on radiation induced hardening was investigated on the base materials, but from the results of nanoindentation test the obvious relief of radiation-induced hardening was not confirmed. The corrosion properties after heavy ion irradiation were also discussed on the base materials in the conditions of electrochemical potentiokinetic reactivation (EPR) test. GB corrosion was observed on the ion-irradiated surface of commercial material of SUS310S. However, no GB corrosion was observed on the irradiated surface of SUS310S with 0.4 % Ta addition, indicating the effect of Ta addition on the improvement of resistance against IASCC..
11. K. Hanada, N. Yoshida, M. Hasegawa, A. Hatayama, K. Okamoto, I. Takagi, T. Hirata, Y. Oya, M. Miyamoto, M. Oya, T. Shikama, A. Kuzmin, Z. X. Wang, H. Long, H. Idei, Y. Nagashima, K. Nakamura, O. Watanabe, T. Onchi, H. Watanabe, K. Tokunaga, A. Higashijima, S. Kawasaki, T. Nagata, S. Shimabukuro, Y. Takase, S. Murakami, X. Gao, H. Liu, J. Qian, R. Raman, M. Ono, Particle balance investigation with the combination of the hydrogen barrier model and rate equations of hydrogen state in long duration discharges on an all-metal plasma facing wall in QUEST, Nuclear Fusion, 10.1088/1741-4326/ab1858, 59, 7, 2019.05, The fuel particle balance during long duration discharges in the Q-shu University Experiment with steady state spherical tokamak (QUEST) was investigated. QUEST has all-metal plasma facing walls (PFWs) that were temperature controlled during the experiments. The presence of a transport barrier for hydrogen (H) at the interface between a plasma-induced deposition layer and metallic substrate was confirmed by nuclear reaction analysis with exposing deuterium plasma. An effective method to evaluate global hydrogen flux to PFWs is proposed, taking advantage of the nature of wall saturation. The outgoing flux of fuel particles from the PFWs just after the plasma termination was proportional to the square of wall-stored H, which indicates that enhanced recombination of solved hydrogen played an essential role in dynamic retention and was in agreement with predictions from the H-barrier model. A simple calculation based on the combination of wall modelling and rate equations of the H states denoted a significant impact of wall modelling on the time response of the plasma density. Hence, a proper wall model including the effects of the deposition layer creating the H barrier is required to be developed, even for all-metal PFW devices..
12. Kenji Matsumoto, Akira Sasaki, Naoki Yoshida, Hideo Watanabe, Surface damage under tribological conditions induced by electrical discharge, Tribology Online, 10.2474/trol.14.214, 14, 4, 214-219, 2019.01, We have seen small black spots or craters on the surface of worn machine parts. They are considered to be caused by discharges of static electricity. However, there is no clear evidence of being caused by discharges of static electricity, as nobody can see the phenomena when discharges are caused there. Using TEM (Transmission Electron Microscope) and SEM (scanning electron microscope), the authors examined the black spots which were found on the lubricated surfaces of machine components and the ones which were artificially caused by spark discharges on a surface of a test material. The results of this study showed that the grains of black spots on the lubricated surface of worn machine parts were almost identical to those which were artificially caused by discharges of static electricity. Moreover, melted wear debris that might have been formed during spark discharge, was found in an oil filter, showing that there was high temperature melting the metal..
13. Y. Hishinuma, M. Tanaka, T. Tanaka, K. Matsuda, Hideo Watanabe, T. Muroga, Microstructure and peeling behavior of MOCVD processed oxide insulator coating before and after ion beam irradiation, Nuclear Materials and Energy, 10.1016/j.nme.2018.06.001, 16, 123-127, 2018.08, The mechanical durability and soundness of the several oxide coating materials used as the electrical insulator and tritium permeation barrier are important design parameters on an advanced liquid breeding blanket system. We tried to investigate the adhesion strength evaluation due to the peeling behavior on the MOCVD processed multilayered oxide coating (Er2O3/Y2O3) on the stainless steel (SUS) substrate before and after Cu2+ ion beam irradiation using the nano-scratch tester. The adhesion strength of the coating material was able to estimate easily from the scratch trace and scratch stress, and the nano-scratch test was suitable method to evaluate the mechanical durability and soundness. After the Cu2+ ion beam irradiation, the adhesion strength was decreased with increasing the displacement per atom (dpa). The adhesion strength degradation by the Cu2+ ion beam irradiation was caused by the embrittlement of the thicker and amorphous Fe-(Y)-O interlayer formation between Y2O3 buffer layer and SUS substrate based on the displacement damage dose effect..
14. Hideo Watanabe, Katsuhito Takahashi, Kazufumi Yasunaga, Yun Wang, Yasuhisa Aono, Yusaku Maruno, Kenichi Hashizume, Effects of an alloying element on a c-component loop formation and precipitate resolution in Zr alloys during ion irradiation, Journal of Nuclear Science and Technology, 10.1080/00223131.2018.1486244, 1-13, 2018.07, It is important to clarify the mechanisms of the dislocation loop formation, dissolution of precipitates to understand the degradation behavior of the fuel cladding tubes in light water reactors (LWR) under neutron irradiation. In this study, 3.2 MeV Ni ion irradiation was carried out at 400°C on Zircaloy-2 and two types of model alloys with and without Fe (Zr-1.5Sn-0.3Fe and Zr-1.5Sn). To understand the effects of hydrogen, 60 and 300 ppm pre-injected Zircaloy-2 samples were also irradiated. The microstructure was observed with a conventional transmission electron microscopy. Additionally, the dissolution of precipitates and the enrichment of the alloying element due to irradiation were analyzed using a spherical aberration (Cs)-corrected high-resolution analytical electron microscope. After ion irradiation at 400°C, the dissolution of Fe-enriched precipitates and the c-component dislocation loops were observed in the region of peak ion damage. Observations by STEM-EDS showed that Fe atoms were enriched in the c-component dislocation loops. On the contrary, the c-component dislocation loops were detected in Fe-containing alloys (Zircaloy-2 and Zr-1.5Sn-0.3Fe alloy) but were not in the Zr-1.5Sn alloy. These results indicate that the dissolution of Fe-enriched precipitates and the enhanced formation of c-component dislocation loops are essential for the degradation of LWR fuel cladding under irradiation..
15. Takuya Nagasaka, Haiying Fu, Nobuyuki Kometani, Takeshi Miyazawa, Takeo Muroga, Hideo Watanabe, Masanori Yamazaki, Takeshi Toyama, Impact property of low-activation vanadium alloy NIFS-HEAT-2 after electron beam welding and neutron irradiation, Fusion Science and Technology, 10.1080/15361055.2017.1352428, 72, 4, 645-651, 2017.11, In order to investigate the effect of post-weld heat treatment (PWHT) and post-irradiation annealing (PIA), electron-beam-weld specimens of the reference low activation vanadium alloy, NIFS-HEAT-2, were neutronirradiated to a fluence of 7.62 × 1023 neutron m-2 (E > 1 MeV) at 563 K in Belgian Reactor-2. In the present experiments, unexpected oxidation of the surface of the samples occurred during the neutron irradiation, and significantly degraded impact properties of the weld metal, while the degradation was not significant for the base metal. The removal of the oxidized layer by electro-polishing improved the impact properties of the weld metal. Although complete removal of the oxidized layer could not be confirmed, it is revealed that impact absorbed energy of the weld metal with post-weld heat treatment at 1073 K was comparable to that of the base metal after the postirradiation polishing. In other words, irradiation embrittlement of the weld metal was successfully suppressed by the PWHT. PIA at 773 K and above was effective to recover the irradiation hardening and irradiation embrittlement. Mechanisms of the irradiation hardening, irradiation embrittlement and its recovery were discussed..
16. K. Hanada, N. Yoshida, T. Honda, Z. Wang, A. Kuzmin, I. Takagi, T. Hirata, Y. Oya, M. Miyamoto, H. Zushi, M. Hasegawa, K. Nakamura, A. Fujisawa, H. Idei, Y. Nagashima, O. Watanabe, T. Onchi, K. Kuroda, H. Long, H. Watanabe, K. Tokunaga, A. Higashijima, S. Kawasaki, T. Nagata, Y. Takase, A. Fukuyama, O. Mitarai, Investigation of hydrogen recycling in long-duration discharges and its modification with a hot wall in the spherical tokamak QUEST, Nuclear Fusion, 10.1088/1741-4326/aa8121, 57, 12, 2017.10, Fully non-inductive plasma maintenance was achieved by a microwave of 8.2 GHz and 40 kW for more than 1 h 55 min with a well-controlled plasma-facing wall (PFW) temperature of 393 K, using a hot wall in the middle-sized spherical tokamak QUEST, until the discharge was finally terminated by the uncontrollability of the density. The PFW was composed of atmospheric plasma-sprayed tungsten and stainless steel. The hot wall plays an essential role in reducing the amount of wall-stored hydrogen and facilitates hydrogen recycling. The behaviour of fuel hydrogen in the PFW was investigated by monitoring the injection and evacuation of hydrogen into and from the plasma-producing vessel. A fuel particle balance equation based on the presence of a hydrogen transport barrier between the deposited layer and the substrate was applied to the long-duration discharges. It was found that the model could readily predict the observed behaviour in which a higher wall temperature likely gives rise to faster wall saturation..
17. Yuki Uemura, Shodai Sakurada, Hiroe Fujita, Keisuke Azuma, Quilai Zhou, Takumi Chikada, Yasuhisa Oya, Yuji Hatano, Naoaki Yoshida, Hideo Watanabe, Makoto Oyaizu, Kanetsugu Isobe, Masashi Shimada, Dean Buchenauer, Robert Kolasinski, Effect of helium irradiation on deuterium permeation behavior in tungsten, Journal of Nuclear Materials, 10.1016/j.jnucmat.2017.04.041, 490, 242-246, 2017.07, In this study, we measured deuterium (D) gas-driven permeation through tungsten (W) foils that had been pre-damaged by helium ions (He+). The goal of this work was to determine how ion-induced damage affects hydrogen isotope permeation. At 873 K, the D permeability for W irradiated by 3.0 keV He+ was approximately one order of magnitude lower than that for un-damaged W. This difference diminished with increasing temperature. Even after heating to 1173 K, the permeability returned to less than half of the value measured for un-damaged W. We propose that this is due to nucleation of He bubbles near the surface which potentially serve as a barrier to diffusion deeper into the bulk. Exposure at higher temperatures shows that the D permeability and diffusion coefficients return to levels observed for undamaged material. It is possible that these effects are linked to annealing of defects introduced by ion damage, and whether the defects are stabilized by the presence of trapped He..
18. Y. Matsukawa, S. Kitayama, K. Murakami, Y. Shinohara, K. Yoshida, H. Maeno, H. L. Yang, T. Toyama, Kazuhiro Yasuda, Hideo Watanabe, A. Kimura, H. Muta, S. Yamanaka, Y. F. Li, Y. Satoh, S. Kano, H. Abe, Reassessment of oxidation-induced amorphization and dissolution of Nb precipitates in Zr−Nb nuclear fuel cladding tubes, Acta Materialia, 10.1016/j.actamat.2017.01.032, 127, 153-164, 2017.04, The surface oxide film of a Zr−2.5Nb alloy subjected to long term corrosion at 633 K in simulated primary coolant of pressurized water reactors has been analyzed. The primary concerns were whether Nb precipitates exhibit amorphization upon oxidation, and whether they dissolve into the matrix, as suggested by previous studies. Their behavior is of particular interest, from the viewpoint of engineering, as the mechanism of improving corrosion resistance of Zr fuel cladding by Nb addition, and from the viewpoint of basic materials science, as the critical condition of solid-state amorphization. If amorphization and dissolution proceed simultaneously, it would follow that amorphization occurs at conditions where both O and Nb atoms are mobile; under such conditions diffusion-induced amorphization has never been observed. It was found that the Nb precipitates exhibited amorphization without dissolution. Some of the inconsistencies among the previous studies were found to be artifacts of materials characterization methods. The final configuration of precipitates was amorphous Nb2O5, which is distinct from the other Nb oxides in terms of its dielectric nature with a wide band gap. The matrix initially contained a large amount of Nb greater than the solubility. Although the excess Nb atoms did not precipitate by thermal aging alone, oxidation was found to enhance their precipitation at this temperature. It appears that amorphization can occur even when the motion of atoms is not frozen-in..
19. Yuta Aihara, Yasuhiro Kamada, Takeshi Murakami, Satoru Kobayashi, Hideo Watanabe, Correlation between magnetic hysteresis properties & vickers hardness in cladded reactor pressure vessel steel, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 10.2320/jinstmet.JAW201702, 81, 10, 475-479, 2017.01, We investigated the microstructure, magnetic hysteresis properties, and micro Vickers hardness of nuclear reactor pressure vessel(RPV) steel cladded with austenitic stainless steel. Characterization of the crystalline structure by electron backscatter diffraction revealed the existence of a delta ferrite phase in the austenitic cladding, and the formation of coarse and fine grain microstructures in the heat affected zone(HAZ)of the RPV steel. The block specimen was cut into small pieces and magnetic hysteresis loops were measured with a vibrating sample magnetometer. Although the saturation magnetization of the RPV steel was constant, the coercivity in the HAZ region decreased gradually as a function of distance from the weld fusion boundary. A linear correlation was confirmed between the coercivity and hardness. This study demonstrates the feasibility of a magnetic evaluation of hardness and microstructures in RPV steel..
20. Y. Oya, H. Fujita, C. Hu, Y. Uemura, S. Sakurada, K. Yuyama, X. Li, Y. Hatano, N. Yoshida, Hideo Watanabe, Y. Nobuta, Y. Yamauchi, M. Tokitani, S. Masuzaki, T. Chikada, Effect of impurity deposition layer formation on D retention in LHD plasma exposed W, Nuclear Materials and Energy, 10.1016/j.nme.2016.07.005, 9, 84-88, 2016.12, Effect of carbon based mixed-material deposition layer formation on hydrogen isotope retention was studied. The tungsten (W) samples were placed at four different positions, namely PI (sputtering erosion dominated area), DP (deposition dominated area), HL (higher heat load area), and ER (erosion dominated area) during 2013 plasma experimental campaign in Large Helical Device (LHD) at National Institute for Fusion Science (NIFS), Japan and were exposed to ∼ 4000 shots of hydrogen plasma in a 2013 plasma experimental campaign. Most of the sample surface except for ER was covered by a mixed-material deposition layer formed by plasma experimental campaign, which consisted of carbon, but some metal impurities were contained. For ER sample, He bubbles were formed due to long term He discharge cleaning and He plasma experiments during the plasma experimental campaign. The additional 1�keV D2+ implantation was performed to evaluated the D retention enhancement by plasma exposure. It was found that both of H and D retentions were clearly increased. In particular, the H retention was controlled by the thickness of the carbon-dominated mixed-material deposition layer, indicating most of the H was trapped by this mixed-material deposition layer. It is concluded that the accumulation of low-Z mixed-material layer on the surface of the first wall is one of key issues for the determination of hydrogen isotope retention in first wall..
21. Hideo Watanabe, K. Yamasaki, A. Higashijima, H. Taguma, T. Nagasaka, T. Muroga, Microstructural changes of Y-doped V-4Cr-4Ti alloys after ion and neutron irradiation, Nuclear Materials and Energy, 10.1016/j.nme.2016.06.001, 9, 447-450, 2016.12, High-purity Y-doped V-4Cr-4Ti alloys (0.1–0.2 wt. % Y), manufactured by the National Institute for Fusion Science (NIFS), were used for this study. Heavy-ion and fission-neutron irradiation was carried out at temperatures 673–873 K. During the ion irradiation at 873 K, the microstructure was controlled by the formation of Ti(C,O,N) precipitates lying on the (100) plane. Y addition effectively suppressed the growth of Ti(C,O,N) precipitates, especially at lower dose irradiation to up to 4 dpa. However, at higher dose levels (12.0 dpa), the number density was almost at the same levels irrespective of the presence of Y. After neutron irradiation at 873 K, fine titanium oxides were also observed in all V alloys. However, smaller oxide sizes were observed in the Y-doped samples under the same irradiation conditions. The detailed analysis of EDS showed that the center of the Ti(C,O,N) precipitates was mainly enriched by nitrogen. The results showed that the contribution of not only oxygen atoms picked up from the irradiation environment but also nitrogen atoms is essential to understand the microstructural evolution of V-4Cr-4Ti-Y alloys..
22. Y. Matsukawa, T. Takeuchi, Y. Kakubo, T. Suzudo, H. Watanabe, H. Abe, T. Toyama, Y. Nagai, The two-step nucleation of G-phase in ferrite, Acta Materialia, 10.1016/j.actamat.2016.06.013, 116, 104-113, 2016.09, By combining atom probe tomography (APT) with transmission electron microscopy (TEM) we have attempted to identify the stage at which solute clusters transform into compounds crystallographically distinct from the matrix, in the precipitation of the G-phase (Ni16Si7Mn6) from ferrite solid solution subjected to isothermal annealing at 673 K. Based on a systematic analysis on the number density, size, composition and structure of solute clusters as a function of annealing time, the nucleation of the G-phase was found to occur via a two-step process: spontaneous growth of solute clusters first, followed by a structural change transforming into the G-phase. Moreover, the structural change was found to occur via another two-step process. There was a time lag between the end of cluster growth to become a critical size (mean diameter: ∼2.6 nm) and the start of the structural change. During the incubation period solute enrichment occurred inside the clusters without further size growth, indicating that the nucleation of the G-phase occurs at the critical size with a critical composition. Judging from the results of APT, TEM and the simulation of electron diffraction patterns, the critical composition was estimated to be Ni16Si3.5(Fe,Cr)3.5Mn6..
23. S. Entani, M. Mizuguchi, H. Watanabe, Liybov Yu. Antipina, Effective fluorination of single-layer graphene by high-energy ion irradiation through a LiF overlayer, ROYAL SOCIETY OF CHEMISTRY, 10.1039/c6ra09631j, RSC Adv. 2016. 6, 68525-68529, 2016.06.
24. V. Kh Alimov, Y. Hatano, N. Yoshida, H. Watanabe, M. Oyaidzu, M. Tokitani, T. Hayashi, Surface modification and sputtering erosion of reduced activation ferritic martensitic steel F82H exposed to low-energy, high flux deuterium plasma, Nuclear Materials and Energy, 10.1016/j.nme.2016.01.001, 7, 25-32, 2016.05, Targets prepared from Reduced Activation Ferritic Martensitic (RAFM) steel F82H were exposed to low-energy (200eV) deuterium (D) plasma at various temperatures with highfluxes of about 1022 D/m2s to various fluences in the range from 1025 to 2.5×1026 D/m2. Under the plasma exposure, micro-structured layers are formed on the target surfaces, and the surface morphology is dependent on the exposure temperature. The erosion yield of the F82H samples increases by a factor of about two as the exposure temperature rises in the range from 403 to 773K..
25. H. Watanabe, S. Arase, T. Yamamoto, P. Wells, T. Onishi, G. R. Odette, Hardening and microstructural evolution of A533b steels irradiated with Fe ions and electrons, Journal of Nuclear Materials, 10.1016/j.jnucmat.2015.12.045, 471, 243-250, 2016.04, Radiation hardening and embrittlement of A533B steels is heavily dependent on the Cu content. In this study, to investigate the effect of copper on the microstructural evolution of these materials, A533B steels with different Cu levels were irradiated with 2.4 MeV Fe ions and 1.0 MeV electrons. Ion irradiation was performed from room temperature (RT) to 350°C with doses up to 1 dpa. At RT and 290°C, low dose (<0.1 dpa) hardening trend corresponded with ΔH ∝ (dpa)n, with n initially approximately 0.5 and consistent with a barrier hardening mechanism, but saturating at ≈0.1 dpa. At higher dose levels, the radiation-induced hardening exhibited a strong Cu content dependence at 290°C, but not at 350°C. Electron irradiation using high-voltage electron microscopy revealed the growth of interstitial-type dislocation loops and enrichment of Ni, Mn, and Si in the vicinities of pre-existing dislocations at doses for which the radiation-induced hardness due to ion irradiation was prominent..
26. V. Kh. Alimov, Y. Hatano, N. Yoshida, H. Watanabe, M. Oyaidzu, M. Tokitani, T. Hayashi, Surface modification and sputtering erosion of reduced activation ferritic martensitic steel F82H exposed to low-energy high flux deuterium plasma, Nuclear Materials and Energy,, 7, (2016), 25-32, 2016.01.
27. H. Kurishita, M. Hatakeyama, M. Nari, S. Matsuo, T. Shikama, N. Ohno, H. Watanabe, K. Tokunaga, T. Hino, Current Activities in the Interface Joint Researcih at Tohoku University- Advanced Education of Radiation Effects on Fusion Materials, Plasma and Fusion Research,, 9, 2016, 440-340, 2015.09.
28. T. Miyazawa, T. Nagasaka, R. Kasada, Y. Hishinuma, T. Muroga, H. Watanabe, T. Yamamoto, S. Nogami, M. Hatakeyama, Evoluation of Irradiation Hardening of Ion-irradiated V-4Cr-4Ti-0.15Y Alloys by Nanoidentatiion Techniques, Journal of Nuclear Materials,, 455, 2014, 440-444, 2015.08.
29. Y. Oya, X. Li, K. Yuyama, L. Zhang, S. Kondo, T . Hinoki, Y. Hatano, H. Watanabe, N. Yoshida, T. Chikada, Thermal desorpiton behavior of deuterium for 6MeV Fe ion irradiated W with various damge concentrations, Journal of Nuclear Materials,, 461, 2015, 336-340, 2015.03.
30. M. Miyamoto, H. Takaoka, K. Ono, S. Morito, N. Yoshida, H. Watanabe, A. Sagara, Crystal orientation dependence of surface modification in molybdenum mirror irradiated with helium ions, Journal of Nuclear Materials,, 455, 2014, 297-300, 2014.07.
31. H. Watanabe, N. Futagami, S. Naitou, N. Yoshida, Microsturucture and Thermal Desorption of Deterium in Heavy Ion Irradiated Pure Tungsten, Journal of Nuclear Materials, 10.1016/j.jnucmat.2014.03.060, 455, 2014, 51-55, 2014.04.
32. H. Kurishita, S. Matsuo, H. Arakawa, T. Sakamoto, S. Kobayashi, K. Nakai, H. Okano, Hideo Watanabe, Naoaki Yoshida, Y. Torikai, Y. Hatano, T. Takida, M. Kato, A. Ikegaya, Y.Ueda, M. Hatakeyama, T. Shikama, Current status of nanostructured tungsten-based materials development, Physica Scripta, 10.1088/0031-8949/2014/T159/014032, T159(2014), 014032(7PP), 1-7, 2014.04.
33. Hiroaki Kurishita, Masahiko Hatakeyama, Minoru Narui, Satoru Matsuno, Tatsuo Shikama, Kohei Tada, Noriyasu Ohno, Takao Takeuchi, Yuji Hatano, Masaki Nishiura, Hideo Watanabe, KAZUTOSHI TOKUNAGA, Tomoaki Hino, Yoshino Ueda, Takeo Muroga, Akio Sagara, Osamu Kaneko, Current Activities in the Interactive Joint Research at Tohoku University – Advanced Evaluation of Radiation Effects on Fusion Materials - *), Plasma and Fusion Research: Regular Articles, 10.1585/pfr.9.3405136, 9, 3405136(2014), 3405136-1-3405136-4, 2014.03.
34. Y. Oya, S. Masuzaki, M. Tokitani, M. sato, H. Uchimura, Naoaki Yoshida, HIDEO WATANABE, Y. Yamaguchi, T. Hino, M. Miyamoto, Y. Hatano, K. Okuno, Comparison of Hydrogen Isotope Retention for Tungsten Probe in LHD Vacuum Vessel during the Experimental Campaigns in 2011 and 2012, Fusion Engineering and Design, 10.1016/j.fusengdes.2013.12.018, 89, (2014), 1091-1095, In Press, 2014.01.
35. KENJI MATSUMOTO, HIDEO WATANABE, Naoaki Yoshida, A TEM Investigation of Crack Formation Mechanism on Chrome-Molybdenum Steel Tested under Real Driving Conditions, Society of Tribologists and Lubrication Engineers, 10.1080/10402004.2013.783660, Tribology Transactions, 56, Issues 6, 897-907, 2013.08.
36. Takuya Nagasaka, Yoshimitsu Hishinuma, Takeo Muroga, HIDEO WATANABE, Hideo Sakasegawa, Hiroyasu Tanigawa, Masami Ando, Analysis on precipitation behavior of reduced activationferritic/martensitic steels with extraction residue tests, Fusion Engineering and Design, 10.1016/j.fusengdes.2013.037, 88,Issues9-10, 2013, 2565-2568, 2013.06.
37. Takuya Nagasaka, Takeo Muroga, WATANABE HIDEO, Takeshi Miyazawa, Masanori Yamazaki, Kenji Shinozaki, Impact property of low-activation vanadium alloy after laser welding and heavy neutron irradiation, Journal of Nuclear Materials, 10.1016/j.jnucmat.2013.05.046, 442,Issues1-3,Supplement 1, 2013, s364-s369, 2013.05.
38. Y.Kamada, J.N.Mohapatra, H. Kikuchi, S. Kobayashi, T. Murakami, HIDEO WATANABE, Neutron Irradiation Effects on Mechanical and Magnetic Properties of Pre-deformed Iron-based Model Alloys, Journal of the Magnetics Society of Japan , Vol.37, No.3-2, 2013, 147-150, 2013.05.
39. Y. Hatano, M. Shimada, T. Otsuka, Y. Oya, V.Kh. Alimov, M. Hara, J. Shi, M. Kobayashi, T. Oda, G. Cao, K. Okuno, T. Tanaka, K. Sugiyama, J. Roth, B. Tyburska-P¨ uschel, J. Dorner, Yoshida Naoaki, N. Futagami, WATANABE HIDEO, M. Hatakeyama, Deuterium trapping at defects created with neutron and ion irradiations in tungsten, NUCLEAR FUSION , 10.1088/0029-5515/53/7/073006, 53,No.7, 2013, 073006-1-073006-7, 2013.05.
40. Tomonori Tokunaga, HIDEO WATANABE, Naoaki Yoshida, Takuya Nagasaka, Ryuta Kasada, Akihiko Kimura, Masayuki Tokitani, Masatoshi Mitsuhara, Hideharu Nakashima, Suguru Masuzaki, Takeshi Takabatake, Nobuyoshi Kuroki, Koichiro Ezato, Satoshi Suzuki, Masato Akiba, Manufacture of Vacuum Plasma Spraying Tungsten with Homogenous Texture on Reduced Activation Ferritic Steel at about 873K, Plasma and Fusion Research: Regular Articles, 10.1585/prf.8.1405111, Volume 8, 1405111(2013), 1405111-1-1405111-6, 2013.05.
41. Yasuhisa Oya, Suguru Masuzaki, Masayuki Tokitani, Naoaki Yoshida, HIDEO WATANABE, Yuji Yamauchi, Tomoaki Hino, Mitsutaka Miyamoto, Yuji Hatano, Kenji Okuno, Enhancement of hydrogen isotope retention capacity for the impurity deposited tungsten by long-term plasma exposure in LHD, Fusion Engineering and Design, 88,Issues9-10, 2013, 1699-1703, 2013.04.
42. WATANABE HIDEO, A. Hiragane, S. Shin, Yoshida Naoaki, Y. Kamada, Effect of stress on radiation-induced hardening of A533B and Fe–Mn model alloys, Journal of Nuclear Materials, 10.1016/j.jnucmat.2013.04.029, 442,Issues1-3,Supplement 1, 2013, s776-s781, 2013.04.
43. Q.Xu, K.Sato, X.Z.Cao, P.Zhang, bB.Y.Wang, T.Yoshiie, HIDEO WATANABE, Naoaki Yoshida, Interactions of deuterium with vacancies induced by ion irradiation in W, Nuclear Instruments and Methods in Physics Research B:Beam Interactions with Materials and Atoms, 315, 2013, 146-148, 2013.04.
44. Muroga Takeo, Nagasaka Takuya, P.F. Zheng, Y. F. Li, WATANABE HIDEO, Dislocation evolution during thermal creep deformation in V-4Cr-4Ti with various thermal and mechanical treatments, Journal of Nuclear Materials, 10.1016/j.jnucmat.2013.03.061, 442, 2013, s354-s359, 2013.03.
45. WATANABE HIDEO, Tokunaga Tomonori, Yoshida Naoaki, Nagasaka Takuya, Muroga Takeo, Investigation on the microstructure of W-coated low-activation alloy V-4Cr-4Ti , Journal of Nuclear Materials, 10.1016/j.jnucmat.2013.02.051, 442, 2013, s292-s296, 2013.03, V系低放射性構造材料(NIFS-HEAT2)にWをロウ付け並びにVPS(Vacumme Plasma Spray)法にて接合し、界面の電子顕微鏡観察を実施した。界面近傍ではV中にチタン析出物が
46. Yasuhisa Oya, Suguru Masuzaki, Tetsuo Fujishima, Masayuki Tokitani, Yoshida Naoaki, WATANABE HIDEO, Yuji Hamauchi, Tomoaki Hino, Mitsutaka Miyamoto, Yuji Hatano, Kenji Okuno, Enhaancement of hydrogen isotope retention in tungsten exposed to LHD plasmas, Journal of Nuclear Materials, 10.1016/j.jnucmat.2013.01.231, 438, 2013, s1055-s1058, 2013.01.
47. Yasuhisa Oya, Masashi Shimada, Tomonori tokunaga, WATANABE HIDEO, Yoshida Naoaki, Yuji Hatano, Ryuta Kasada, Takuya Nagasaka, Akihiko Kimura, Kenji Okuno, Behavior of deuterium retention and surface morphology for VPS-W/F82H, Journal of Nuclear Materials, 10.1016/j.jnucmat.2013.01.321, 442, 2013, s242-s245, 2013.01.
48. T.Tokunaga, WATANABE HIDEO, Yoshida Naoaki, T.Nagasaka, R.Kasada, Y.Lee, A.Kimura, M.Tokitani, T.Hinoki, H.Nakasima, S.Masuzaki, T.Takabatake, N.Kuroki, K.Ezato, S.Suzuki, M.Akiba, Development of high-grade VPS-tungsten coating on F82H reduced activation steel , Journal of Nuclear Materials, 10.1016/j.jnucmat.2012.11.004, 442, 2013, s287-s291, 2012.12.
49. Yasuhiro Kamada, WATANABE HIDEO, Seiji Mitani, Jitendra Narayana Mohapatra, Hiroaki Kikuchi, Satoru Kobayashi, Masaki Muzuguchi, Koki Takanashi, Ion-irradiation enhancement of materials degradation in Fe–Cr single crystals detected by magnetic technique, Journal of Nuclear Materials, 10.1016/j.jnucmat.2012.11.042, 442, 2013, s861-s864, 2012.12.
50. N. Ohno, Y. Hirahata, M. Yamagiwa, S. Kajita, M. Takagi, Yoshida Naoaki, Reiko Yoshihara, Tomonori Tokunaga, M. Tokitani, Influence of crystal orientation on damages of tungsten exposed to helium plasma, Journal of Nuclear Materials, accepted for publication, 2012.12.
51. WATANABE HIDEO, A. Hiragane, S. Shin, Yoshida Naoaki, Kamada Yasuhiro, The effects of stress on radiation-induced hardening of A533B and Fe-Mn alloys , Journal of Nuclear Materials, accepted for publication, 2012.12.
52. Tomonori Tokunaga, WATANABE HIDEO, Yoshida Naoaki, T. Nagasaka, R. Kasada, A. Kimura, M. Tokitani, M. Mitsuhara, H. Nakashima, S. Masuzaki, T. Takabatake, N. Kuroki, K. Ezato, S. Suzuk, M. Akiba, Manufacture of vacuum plasma sprayed tungsten with homogenous texture on metallic substrate at low temperatures, Plasma and Fusion Research, submitted, 2012.12.
53. Influence of Heat Treatment after Ion Irradiation on Joint Strength of Copper and Tungsten.
54. HIDEO WATANABE, S.Masaki, S.Masubuchi, Naoaki Yoshida, K.Dohi, Effects of Mn addition on dislocation loop formation in A533B and model alloys, Jouenal of Nuclear Materials, 10.1016/j.jnucmat.2012.08.029, 439, 2013, 268-275, 2012.09.
55. WATANABE HIDEO, M.Masaki, S.Masubuchi, Yoshida Naoaki, Kamada Yasuhiro, Effects of Mn addition on Dislocation Loop Formation in A533B and Model Alloys Journal of Nuclear Materials, Journal of Nuclear Materials, 439, 268-275, 2012.08, 実用材料であるA533B並びにFeモデル合金を用いてMn添加の影響が転位ループ(マトリクス欠陥)の数密度増加に起因するものであることを、電子線照射並びにイオン照射実験から秋化にした。.
56. Microstructure Changes of Pure Copper after Irradiation under Periodic Temperature Variation.
57. Masashi Shimada, Y. Hatano, Y. Oya, T. Oda, M. Hara, G. Cao, M. Kobayashi, M. Sokolov, HIDEO WATANABE, B. Tyburska-Puschel, Y. Ueda, P. Calderoni, K. Okuno, Overview of the US–Japan collaborative investigation on hydrogen isotope retention in neutron-irradiated and ion-damaged tungsten
, Fusion Engineering and Design, 10.1016/j.fusengdes.2012.02.103, 87, 2012, 1166-1170, 2012.04.
58. S.K. Sharma, hideki zushi, Naoaki Yoshida, HIDEO WATANABE, M. Osakabe, Y. Takeri, M. Hasegawa, T. Tanabe, KAZUTOSHI TOKUNAGA, kazuaki hanada, Hiroshi Idei, M. Sakamoto, Kazuo Nakamura, Akihide Fujisawa, S. Tashima, Analysis of PWI footprint traces and material damage on the first walls of the spherical tokamak QUEST, Fusion Engineering and Design, 10.1016/j.fusengdes.2011.10.001, 87, 2012, 77-86, 2011.11.
59. Kazuhito Ohsawa, Keisuke Eguchi, Hideo Watanabe, Masataka Yamaguchi and Masatoshi Yagi, Configuration and binding energy of multiple hydrogen atoms trapped in movovacancy in bcc transition metals, PHYSICAL REVIEW B, 10.1103/PhysRevB.85.094102, 85, 2012, 094102-1~8, 2011.11.
60. Takuya Nagasaka, Yoshimitsu Hishinuma, Takeo Muroga, Yanfen Li, HIDEO WATANABE, Hiroyasu Tanigawa, Hideo Sakasegawa, Masami Ando, Extraction residue analysis on F82H-BA07 heat and other reduced activation ferritic/martensitic steels , Fusion Engineering and Design, 10.1016/j.fusengdes.2010.11.006, 86, 2011, 2581-2584, 2011.10.
61. Yasuhisa Oya, Masashi Shimada, Makoto Kobayashi, Takuji Lda, Masanori Hara, Hideo Watanabe, Yuji Hatano, Pattorick Calderoni and Kenji Okuno, Comparison of deuterium retention for ion-irradiated and neutron-irradeated tungsten, PHYSICA SCRIPTA, 10.1088/0031-8949/2011/T145/014050, T145, 014050(5PP), 2011.05.
62. Yasuhiro Kamada, Hideo Watanabe, Seiji Mitani, Jun-ichi Echigoya, Hiroaki Kikuchi, Satoru Kobayashi and Koki Takanashi , Magnetic Properties of Ion Irradiated Epitaxial Fe Films, Joural of Physics : Conference Series, Vol. 266(2011) pp.012035/1-5, Vol.50, No.9 pp.2134to2138, 2011.04.
63. Nagasaka Takuya, Muroga Takeo, WATANABE HIDEO, Kasada Ryota, Kimura Akihiko, Mechanial properties of V-4Cr-4Ti alloy after first-wall coating with tungsten, Journal of Nuclear Materials, 306-309, 417 , 2011.04.
64. T.Muroga,T.Nagasaka,H.Watanabe,M.Yamazaki, The effect of final heat treatment temperature on radiation response of V-4Cr-4Ti, Journal of Nuclear Materials, 2011.04.
65. WATANABE HIDEO, Yoshida Naoaki, Nagasaka Takuya, Muroga Takeo, The microstructure and hardness changes of neutron irradiated weld joint of vanadium alloy, Journal of Nuclear Materials, 2011.04.
66. Takuya Nagasaka, Yoshimitsu Hishinuma, Takeo Muroga, Yanfen Li, HIDEO WATANABE, Hiroyasu Tanigawa, Hideo Sakasegawa, Masami Ando, Extraction residue analysis on F82H-BA07 heat and other reduced activation
ferritic/martensitic steels, Fusion Engineering and Design, 10.1016/j.fusengdes.2010.11.006, 86, 2011, 2581-2584, 2010.12.
67. Hideo WATANABE,Naoaki YOSHIDA, Environmntal EffectS on Titanium Oxide Formation in V-4Cr-4Ti Alloys, Reports of Research Institute for Applied Mechanics,Kyushu University, 139, 81-84, 2010.09.
68. T.Muroga,T.Nagasaka,J.M.Chen,Y.F.Li,H.Watanabe, Microstructure of creep-deformed V-4C-4Ti strengthened by precipitation and cold rollng, Journal of Nuclear Materials, 606-609, 386-388 606-609, 2009.04.
69. Y.Sumino, H.Watanabe, N.Yoshida, The microstructural evolution of precipitate strengthened copper alloys by varying temperature irradiation, Journal of Nuclear Materials, 386-388 654-657, 2009.04.
70. H.Watanabe, A.Higashijima, N.Yoshida, T.Nagasaka,T.Muroga, The microstructure of laser welded Y doped V-4C-4Ti alloys after ion irradiation, Journal of Nuclear Materials, 386-388 598-601, 2009.04.
71. Yasuhiro Kamada, Hideo Watanabe, Seiji Mitani, Jun-ichi Echigoya, Hiroaki Kikuchi, Satoru Kobayashi Naoaki Yoshida and Koki Takanashi , Effects of Room Temperaturre Heavy-Ion Irradiation on Magnetic and Electrical Properties of a Single Crystalline Iron Thin Film
, Materials Transactions, Vol.50, No.9 pp.2134to2138, 2009.04.
72. Q. Xu, T. Yoshiie, H. Watanabe, and N. Yoshida, Effects of oversized element Sn on diffusion of Intersititial cluster in Ni irradiated by ions and neutrons, Journal of Nuclear Materials, 367-370(2007)361-367, 2007.05.
73. H. Watanabe, K, Yamazaki, A. Higashizima, N. Yoshida, T. Nagasaka and T. Muroga, The microstructure of laser welded V-4Cr-4Ti alloy after neutron irradiation, Journal of Nuclear Materials, 367-370(2007)794-799, 2007.05.
74. T. Nagasaka,T. Muroga, K. Fukumoto, H. Watanabe, M. L. Grossbeck, J. Chen, Development of fabrication technology for low activation vanadium alloys as fusion blanket structural materials, Nulc. Fusion , Vol.5.618-625, 2006.05.
75. Y. Sumino, H. Watanabe, N. Yoshida, and T,Muroga, The Microstructure of Pure Copper After Stepwise Change of Irradiation Temperature, Material Scicence Forum, 475-479, 1479-1482, Vols. 475-479(2005)pp.1479-1482, 2005.10.
76. H. Watanabe, M. Nagamine, K. Yamasaki, N. Yoshida, Nam-JIn Heo, T. Nagasaka and T,Muroga, The Microstructure of Laser Welded V-4Cr-4Ti Alloys After Ion Irradiation, Material Scicence Forum, 475-479, 1491-1495, Vols. 475-479(2005)pp.1491-1496, 2005.10.
77. Effects of Ion Irradiation on Laser Welded V-4Cr-4Ti Alloy(NIFS-HEAT2).
78. Recent Progress of Varying Temperature Irradiation Experiments on Microstructure Development in Austenitic Stainless Steels.
79. M. Hatakeyama, H. Watanabe, T. Muroga and N. Yoshida, The precipitation behavior of ion irradiated V-4Vr-4Ti alloys at various oxygen and nitrogen levels, Journal of Nuclear Materials, 10.1016/j.jnucmat.2004.04.076, 329, 420-424, 329-333(2004)420-424, 2004.01.
80. Ham-Jin HEO, T. Nagasaka, T. Muroga, A. Nismura, K. Shinozaki, H. Watanabe, Mechanical Properites of Laser Weldment of V-4Cr-4Ti Alloy, Fusion Science and Technology, 44, 2, 470-474, Vol.44.470-474, 2003.09.
81. H. Watanabe, D. J. Edwards, Y. Aono, N. Yoshida, Microstructure of Neutron Irradiated SS316L/DS-Cu Joint, Journal of Nuclear Materials, 10.1016/S0022-3115(02)01205-9, 307, 335-338, Vol.307-311.335-338, 2002.12.
82. H. Watanabe, T. Muroga, N. Yoshida, Effects of Temperature Variation Change on Vadadium Alloys Irradiated in HFIR, Journal of Nuclear Materials, Vol.307-311.403-407, 2002.12.
83. H. Watanabe, M. Suda, T. Muroga, N. Yoshida, Oxide Formation of a Purified V-4Cr-4Ti Alloys During Heat Treatment and Ion Irradiation, Journal of Nuclear Materials, 10.1016/S0022-3115(02)01097-8, 307, 408-411, Vol.307-311.408-411, 2002.12.
84. H. Watanabe, N. Yoshida, ODS銅/ステンレス接合材料の中性子照射による組織変化, まてりあ、日本金属学会, 第40巻、第12号、1027, 2002.03.
85. H. Watanabe, T. Muroga, N. Yoshida, Effects of Varying Temperature Irradiation of the Microstructure of Neutron Irradiated Austenitic Stainless Steels, 日本金属学会, 2002.03.
86. T. Muroga, S.J.Zinkle, A. L. Qualls, H. Watanabe, Varying Temperature Irradiation Experiment in HFIR, Journal of Nuclear Materials, 10.1016/S0022-3115(01)00675-4, 299, 2, 148-156, Vol. 299 148-156, 2001.11.
87. K. Yasunaga, H. Watanabe, N. Yoshida, T. Murorga, N. Noda, Correlation between Defect Structure and Hardness in Tantalum Irradiated by Heaby Ions, Journal of Nuclear Materials, 10.1016/S0022-3115(00)00354-8, 283, 179-182, Vol.283-287 179-182, 2000.10.
88. H. Watanabe, T. Arinaga, K. Ochiai, T. Muroga, N. Yoshida, Microstructure of Vanadium Alloys during Ion Irradiated with Stepwise Change of Temperature, Journal of Nuclear Materials, 10.1016/S0022-3115(00)00307-X, 283, 286-290, Vol. 283-287 286-290, 2000.10.
89. D. Hamaguchi, T. Muroga, H. Watanabe, N. Yoshida, Influence of Variable Temperatures Irradiation on Microstructural Evolution in Phosphorus Doped Fe-Cr-Ni alloys, Journal of Nuclear Materials, 10.1016/S0022-3115(00)00133-1, 283, 319-323, Vol. 283-287 319-323, 2000.10.