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Futakawa, Masatoshi; Kogawa, Hiroyuki; Hasegawa, Shoichi; Ikeda, Yujiro; Riemer, B.*; Wendel, M.*; Haines, J.*; Bauer, G.*; Naoe, Takashi; Okita, Kohei*; et al.
Journal of Nuclear Materials, 377(1), p.182 - 188, 2008/06
Times Cited Count：28 Percentile：85.1(Materials Science, Multidisciplinary)no abstracts in English
Kogawa, Hiroyuki; Shobu, Takahisa; Futakawa, Masatoshi; Ahmed, B.*; Haga, Katsuhiro; Naoe, Takashi*
Journal of Nuclear Materials, 377(1), p.189 - 194, 2008/06
Times Cited Count：12 Percentile：61.74(Materials Science, Multidisciplinary)It is important to understand the bubble formation behavior from the viewpoint of development on the micro bubble injection method into mercury to mitigate pressure waves in mercury target for spallation neutron source. Observation of bubble formation was carried out by using the high intense X-ray from SPring-8. A thin nozzle of 100 
m in inner diameter and 200 m in outer diameter was installed into the bottom of vessel filled with mercury. Helium gas was injected to mercury through the nozzle. Bubble formation behavior in mercury was compared with that in water. Bubble formation behavior in mercury was quite different from that in water; though the bubble grew contacting the inside of the nozzle in water, it grew surrounding the outside of the nozzle in mercury. It seems that the wettability between the liquid and material of the nozzle causes the difference of bubble formation. This paper will discuss about the wettability effect on the bubble generation.
Kogawa, Hiroyuki; Hasegawa, Shoichi; Futakawa, Masatoshi; Riemer, B.*; Wendel, M.*; Haines, J.*
Journal of Nuclear Materials, 377(1), p.195 - 200, 2008/06
Times Cited Count：3 Percentile：23.55(Materials Science, Multidisciplinary)In beam test was carried out at the LANSCE-WNR to investigate pressure wave mitigation in mercury targets for the MW-class spallation neutron sources under international collaboration between SNS and JSNS. A mercury loop with micro bubble generator was used for the target. The loop target consists of the rectangular pipe which was made of stainless steel. The total length of the loop is about 2 m. Strain sensors were set on many points of loop to measure the strain on the pipe wall caused by the pressure wave. The maximum strain at 350 mm apart from the proton bombarded point appeared after 5.5 ms after the proton bombardment. The wave propagation velocity was slower than the stress wave and the pressure wave propagation velocities and became 65 m/s in the IBBTL. Numerical analysis result shows that the maximum strain at 350 mm apart from the proton bombarded point appeared at 5.5 ms after proton bombardment as well as the experimental due to interaction between liquid and solid.
CKikuchi, Kenji; Kamata, Kinya*; Ono, Mikinori*; Kitano, Teruaki*; Hayashi, Kenichi*; Oigawa, Hiroyuki
Journal of Nuclear Materials, 377(1), p.232 - 242, 2008/06
Times Cited Count：17 Percentile：72.86(Materials Science, Multidisciplinary)Corrosion behavior of F82H and JPCA was studied in the circulating LBE loop. Those are candidate materials of Japanese ADS beam windows. Maximum temperatures were kept to 450 and 500 C with 100 C constant temperature difference. Main flow velocity was 0.4 to 0.6 m/s in every case. Oxygen concentration was controlled to 2
4
10
mass% although there was an exception. Testing time durations were 500 to 3000 hrs. Round bar type specimens were put in the circular tube of the loop. Electron beam welded joint in the middle part of specimens were also studied. Optical micrograph, electron micrograph, X-ray element analyses and X-ray diffraction were investigated. Consequently for a long-term behavior a linear law is recommended to predict corrosion in the ADS beam design.
Yoshiie, Toshimasa*; Xu, Q.*; Sato, Koichi*; Kikuchi, Kenji; Kawai, Masayoshi*
Journal of Nuclear Materials, 377(1), p.132 - 135, 2008/06
Times Cited Count：11 Percentile：59.16(Materials Science, Multidisciplinary)Reaction kinetic analysis was used to estimate the damage evolution in window materials of 800 MWth ADS. Parameters were fitted to F82H of the STIP-II experiment and EC316LN of the STIP-I experiment. In F82H, the concentration of bubbles was almost constant and the bubble size increased, while the concentration of interstitial type dislocation loops increased and their size was constant between 310
and 300 dpa. EC316LN showed almost the same behavior. Swelling increased almost linearly with irradiation dose above 3 dpa between 673 K and 773 K.
Teshigawara, Makoto; Wakui, Takashi; Maekawa, Fujio; Futakawa, Masatoshi; Kato, Takashi; Kikuchi, Kenji; Nakamura, Koji*; Fukai, Takashi*; Yoshida, Nobutoshi*; Naoe, Takashi*; et al.
no journal, ,
The spallation neutron source facility (JSNS) in J-PARC project is under construction. Highest neutron intensity, especially peak intensity, is provided to neutron beam users in JSNS. However, the pressure wave caused by the intense pulsed proton beam gives vibration related pitting damage on the target beam window, resulting in a shorter life-time. It is very important to monitor the pitting damage of the target beam window to estimate its life-time. Laser Doppler method is a useful acoustic vibration measurement technique to monitor damage caused by pitting damage. We adopted a retro-reflecting corner cube mirror to enable this measurement. We developed a retro-reflective corner cube mirror with the reflectivity of 12 %, which is made by Ni using electroforming. Finally, we could install the retro-reflective mirror on the real target container with an optimized brazing method (Ag based brazing).
Ouchi, Nobuo; Yoshikawa, Hiroshi; Sakaki, Hironao; Ueno, Akira; Hasegawa, Kazuo
no journal, ,
no abstracts in English
Kikuchi, Kenji; Saito, Shigeru; Tsujimoto, Kazufumi; Kawai, Masayoshi*; Dai, Y.*
no journal, ,
STIP specimens irradiated at SINQ target 3 included helium and hydrogen isotopes generated in the spallation reaction process. A total amount of residual gases with having mass four in the specimens were measured by mass spectrometer or helium leak detector. JPCA is a modified austenitic stainless steel by adding Ti. F82H is a reduced-activation ferritic-martensitic steel developed in fusion program. Specimens are TEM disks and pulled tensile specimens. Samples were heated up to 2000C and allresidual gases were released. A amount of gas was compared with the reported values on the different steels and agreed with other data within 50%.
Kikuchi, Kenji; Saito, Shigeru; Hamaguchi, Dai; Tezuka, Masao
no journal, ,
JLBL-1 is a circulation loop of Pb-Bi. The loop was operated more than 9000 hrs. During an operation pieces of Pb-Bi are sampled from loop tube, test pieces, filter, electro-magnetic pump and valve. We observed Fe-Cr precipitation at lower temperature part. These materials are dissolved at high temperature part of test loop and transported to the lower temperature part. Interesting matter is how much materials are exited in the Pb-Bi. We analysed Fe, Cr and Ni in the portion of sampled Pb-Bi by ICP mass spectrometer and found that Cr and Fe was over the saturated valuesin LBE.
Kikuchi, Kenji; Tezuka, Masao; Yamamura, Tsutomu*
no journal, ,
Wetting experiment of Pb-Bi was done in the gold image furnace by changing temperatures up to 500 degree C. A piece of solid Pb-Bi was put on the plate made of aluminum, SS316L and cast iron. Shapes are observed by microscope and data was recorded by video system. Contacting angles between Pb-Bi and metal plate are meadured. Bad wetting was described by the order of Aluminum, SS316 and Cast iron. Bad wetting makes good corrosion resistenace but bad heat transfer. Wetting property is seemed to be a parameter to be compatible with Pb-Bi.
Nishihara, Kenji; Kikuchi, Kenji
no journal, ,
Irradiation damage to the beam window in the concept of 800 MWth accelerator-driven system is evaluated. Transport of proton and neutron up to 1.5 GeV, which is incident proton energy, is calculated by PHITS code that is the Monte Carlo code for particle and heavy ion and TWODANT code that is 2-dimentional deterministic transport code. The beam window is irradiated at center of the accelerator-driven system by 20 MW proton beam and fast neutron from the core during 300 effective full power days. A displacement, production rate of hydrogen and helium isotopes, and neutron and proton fields is estimated, assuming the realistic beam profiles.
