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Journal Articles

Structural characterization and magnetic behavior of uranium compound U$$_2$$Pt$$_6$$Al$$_{15}$$

Haga, Yoshinori; Sugai, Takashi*; Matsumoto, Yuji*; Yamamoto, Etsuji

JPS Conference Proceedings (Internet), 29, p.013003_1 - 013003_5, 2020/02

Journal Articles

Off-gas processing system operations for mercury target vessel replacement at J-PARC

Kai, Tetsuya; Uchida, Toshitsugu; Kinoshita, Hidetaka; Seki, Masakazu; Oi, Motoki; Wakui, Takashi; Haga, Katsuhiro; Kasugai, Yoshimi; Takada, Hiroshi

Journal of Physics; Conference Series, 1021(1), p.012042_1 - 012042_4, 2018/06

 Times Cited Count:0 Percentile:0.11

Journal Articles

Status quo of the injector for the IFMIF/EVEDA prototype accelerator

Shinto, Katsuhiro; Ichikawa, Masahiro; Takahashi, Yasuyuki*; Kubo, Takashi*; Tsutsumi, Kazuyoshi; Kikuchi, Takayuki; Kasugai, Atsushi; Sugimoto, Masayoshi; Gobin, R.*; Girardot, P.*; et al.

Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1009 - 1012, 2014/10

The prototype accelerator is being developed as an engineering validation for the International Fusion Materials Irradiation Facility (IFMIF) equipped with an accelerator-driven-type neutron source for developing fusion reactor materials. This prototype accelerator is a deuteron linear accelerator consisting of an injector, an RFQ, a superconducting linac and their auxiliaries. It aims to produce a CW D$$^+$$ beam with the energy and current of 9 MeV/125 mA. The injector test was completed at CEA/Saclay in 2012 for producing a CW H$$^+$$ beam and a CW D$$^+$$ beam with the energy and current of 100 keV/140 mA. After the beam test at CEA/Saclay, the injector was transported to the International Fusion Energy Research Centre (IFERC) located in Rokkasho, Aomori, Japan. In the end of 2013, installation of the injector was started at IFERC for the injector beam test beginning from summer 2014 in order to obtain better beam qualities to be satisfied with the injection and acceleration of the following accelerators. In this paper, some results of the injector beam test performed at CEA/Saclay and the status quo of the installation of the injector at IFERC are presented.

Journal Articles

Development of Au-In-Cd decoupler by a Hot Isostatic Pressing (HIP) technique for short pulsed spallation neutron source

Oi, Motoki; Teshigawara, Makoto; Harada, Masahide; Naoe, Takashi; Maekawa, Fujio; Kasugai, Yoshimi

Journal of Nuclear Materials, 450(1-3), p.117 - 122, 2014/07

 Times Cited Count:3 Percentile:28.59(Materials Science, Multidisciplinary)

In order to utilize Au-In-Cd alloy as a decoupler, it is required to bond between the Au-In-Cd alloy and aluminum alloy with enough bonding strength (more than 30 MPa). We adopted a Hot Isostatic Pressing (HIP) technique to realize bonding between Au-In-Cd and aluminum alloy, because it is available for curved shape of moderator vessel. As a HIP conditions of the temperature of 535 $$^{circ}$$C, pressure of 100 MPa and holding time of 1 hour, we got enough tensile strength of the bonding surface (86.6 MPa). It is larger than the required strength of 30 MPa.

Journal Articles

Activation detector measurements at the hadron absorber of the NuMI neutrino beamline at Fermilab

Matsuda, Norihiro; Kasugai, Yoshimi; Matsumura, Hiroshi*; Iwase, Hiroshi*; Toyoda, Akihiro*; Yashima, Hiroshi*; Sekimoto, Shun*; Oishi, Koji*; Sakamoto, Yukio*; Nakashima, Hiroshi; et al.

Progress in Nuclear Science and Technology (Internet), 4, p.337 - 340, 2014/04

The Neutrinos at the Main Injector (NuMI) at Fermilab produces intense neutrino beam to investigate the phenomena of the neutrino mixing and oscillation. The Hadron Absorber, consists of thick blocks of aluminum, iron and concrete, is placed at the end of decay volume as a dump for primary proton and secondary particles generated in NuMI. In order to estimate the shielding effect, the reaction rate measurements with activation detector were carried out on the back surface of the absorber. The induced activities in the detectors were measured by analyzing their $$gamma$$-ray spectra using HPGe detectors. Two kind of peak was showed on two-dimensional distributions of obtained reaction rates at right angle to the beam direction. One was strong peaks at the both horizontal side. And, another smaller was at the top. It was concluded that these peaks were the results of particles streaming through the gaps in the Hadron Absorber shielding.

Journal Articles

Electronic stopping power dependence of ion-track size in UO$$_{2}$$ irradiated with heavy ions in the energy range of $$sim$$1MeV/u

Ishikawa, Norito; Sonoda, Takeshi*; Sawabe, Takashi*; Sugai, Hiroyuki*; Sataka, Masao*

Nuclear Instruments and Methods in Physics Research B, 314, p.180 - 184, 2013/11

 Times Cited Count:16 Percentile:82.29(Instruments & Instrumentation)

In order to investigate electronic stopping power dependence of ion-track size in UO$$_{2}$$, ion-tracks in UO$$_{2}$$ irradiated with various ions with the specific energy in the order of 1 MeV/u have been observed by a transmission electron microscope. The ion-tracksize shows monotonic increase as a function of the electronic stopping power. Theion-track size obtained for UO$$_{2}$$ is smaller than that obtained for CeO$$_{2}$$, although these two compounds have same crystallographic structure and similar thermal properties. The ion-track sizes for irradiations with ions having relatively low energy of about1 MeV/u are smaller than those expected from the thermal spike models based on melting temperature criterion. The possible interpretations for the unusually smallion-tracks observed for UO$$_{2}$$ are discussed.

Journal Articles

Fitting method for spectrum deduction in high-energy neutron field induced by GeV-protons using experimental reaction-rate data

Kasugai, Yoshimi; Matsuda, Norihiro; Sakamoto, Yukio; Nakashima, Hiroshi; Yashima, Hiroshi*; Matsumura, Hiroshi*; Iwase, Hiroshi*; Hirayama, Hideo*; Mokhov, N.*; Leveling, A.*; et al.

Reactor Dosimetry; 14th International Symposium (ASTM STP 1550), p.675 - 689, 2012/08

Under the collaborative study project of JASMIN, shielding experiments has been carried out using the anti-proton target station (Pbar) of Fermilab. In the experiment, the multi-foil activation technique was utilized, and the neutron spectra in high-energy region between 1 and 100 MeV were deduced by using the "fitting method", which is newly developed. In this method, we made an assumption that neutron energy spectra could be expressed with a simple function. The validity of the fitting method was confirmed by comparison with the results of the unfolding method and the theoretical calculations. Finally, it was found that there are simple correlations between reaction rates and the adjusting parameters in the fitting function. The correlations are useful for estimating the adjusting parameters easily, and a neutron spectrum in the high-energy region can be deduced from a set of reaction-rate data without the complicated calculations of unfolding.

JAEA Reports

Result of study on storage plan for irradiated components generated at MLF in J-PARC

Kinoshita, Hidetaka; Wakui, Takashi; Matsui, Hiroki; Maekawa, Fujio; Kasugai, Yoshimi; Haga, Katsuhiro; Teshigawara, Makoto; Meigo, Shinichiro; Seki, Masakazu; Sakamoto, Shinichi; et al.

JAEA-Technology 2011-040, 154 Pages, 2012/03

JAEA-Technology-2011-040.pdf:8.08MB

In the MLF, relatively high level irradiated components will be generated. Therefore, these components can not be kept in standard facilities. For the irradiated components at the MLF, the storage plan using the facilities in the Nuclear Science Research Institute has been studied, but the concrete plan is not decided yet. In this report, outline of the components, prehistory of the studying for storage, schedule of the component generation and status of the possible facility, which is a hot laboratory, are described. Resulting from the comparison between the generation schedule and the plan of the hot laboratory, the difference is very large. Present status of the hot laboratory and the cost estimation of the modification to use for storage of the MLF components were studied. Using the hot laboratory seems not to have advantage from the view point of cost and modification method. Therefore, the study on a new storage facility construction will be started as soon as possible.

JAEA Reports

Influence of Great East Japan Earthquake on neutron source station in J-PARC

Sakai, Kenji; Sakamoto, Shinichi; Kinoshita, Hidetaka; Seki, Masakazu; Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; Naoe, Takashi; Kasugai, Yoshimi; Tatsumoto, Hideki; et al.

JAEA-Technology 2011-039, 121 Pages, 2012/03

JAEA-Technology-2011-039.pdf:10.87MB

This report investigates the behavior, damage and restoration of a neutron source station of the MLF at the Great East Japan Earthquake and verified the safety design for emergency accidents in the neutron source station. In the MLF, after an occurrence of the Earthquake, strong quakes were detected at the instruments, the external power supply was lost, all of the circulators shut down automatically, and the hydrogen gas was released. The leakages of mercury, hydrogen and radio-activation gases did not occur. While, the quakes made gaps between the shield blocks and ruptured external pipe lines by subsidence around the building. But significant damages to the components were not found though the pressure drop of compressed air lines influenced on a target trolley lock system and so on. These results substantiated the validity of the safety design for emergency accidents in the source station, and suggested several points of improvement.

Journal Articles

Influence of Great East Japan Earthquake on neutron target station in J-PARC

Sakai, Kenji; Futakawa, Masatoshi; Takada, Hiroshi; Sakamoto, Shinichi; Maekawa, Fujio; Kinoshita, Hidetaka; Seki, Masakazu; Haga, Katsuhiro; Kogawa, Hiroyuki; Wakui, Takashi; et al.

Proceedings of 20th Meeting of the International Collaboration on Advanced Neutron Sources (ICANS-20) (USB Flash Drive), 6 Pages, 2012/03

This report investigates behaviors and damages of each component in a neutron target station of the MLF at the J-PARC at the time of the Great East Japan Earthquake (GEJE). At the date of the GEJE, in the MLF, strong quakes were detected at several instruments, an external power supply were lost, all of the circulation systems were shut down automatically, and a hydrogen gas was released as planned. Leakage of activation liquids and gases did not occur. While, the quakes made gaps between shield blocks and ruptured external pipe lines for air and water by subsidence. But significant damages on the components of the target station were not found though a loss of compressed air supply affected lock systems with air cylinders and pneumatic operation values. These results substantiated a validity of safety design on the target station for emergency accidents.

Journal Articles

Electronic structure of heavy fermion uranium compounds studied by core-level photoelectron spectroscopy

Fujimori, Shinichi; Okochi, Takuo*; Kawasaki, Ikuto; Yasui, Akira; Takeda, Yukiharu; Okane, Tetsuo; Saito, Yuji; Fujimori, Atsushi; Yamagami, Hiroshi; Haga, Yoshinori; et al.

Journal of the Physical Society of Japan, 81(1), p.014703_1 - 014703_9, 2012/01

 Times Cited Count:35 Percentile:83.28(Physics, Multidisciplinary)

High-energy-resolution core-level and valence-band photoelectron spectroscopic studies were performed for the heavy Fermion uranium compounds UGe$$_2$$, UCoGe, URhGe, URu$$_2$$Si$$_2$$, UNi$$_2$$Al$$_3$$, UPd$$_2$$Al$$_3$$, and UPt$$_3$$ as well as typical localized and itinerant uranium compounds to understand the relationship between the uranium valence state and their core-level spectral line shapes. The core-level spectra of UGe$$_2$$, UCoGe, URhGe, URu$$_2$$Si$$_2$$, and UNi$$_2$$Al$$_3$$ are rather similar to those of itinerant compounds, suggesting that U 5$$f$$ electrons in these compounds are well hybridized with ligand states. On the other hand, the core-level spectra of UPd$$_2$$Al$$_3$$ and UPt$$_3$$ show considerably different spectral line shapes from those of the itinerant compounds, suggesting that U 5$$f$$ electrons in UPd$$_2$$Al$$_3$$ and UPt$$_3$$ are less hybridized with ligand states, leading to the correlated nature of U 5$$f$$ electrons in these compounds.

Journal Articles

Shielding experiments under JASMIN collaboration at Fermilab, 4; Measurement and analyses of high-energy neutron spectra in the anti-proton target station

Matsuda, Norihiro; Kasugai, Yoshimi; Sakamoto, Yukio; Nakashima, Hiroshi; Matsumura, Hiroshi*; Iwase, Hiroshi*; Kinoshita, Norikazu*; Hirayama, Hideo*; Yashima, Hiroshi*; Mokhov, N.*; et al.

Journal of the Korean Physical Society, 59(2), p.2055 - 2058, 2011/08

 Times Cited Count:0 Percentile:0(Physics, Multidisciplinary)

It is important to obtain neutron spectra and its intensity on shielding experiment. Deduction of high-energy neutron spectra were done using fitting and unfolding methods based on the shielding data obtained at the anti-proton (pbar) target station in Fermilab. The neutron spectra for fitting method is useful to be easily obtained and the values gave reasonable results compared with nuclear data. Therefore, that for unfolding methods included inconsistency. Furthermore, the deduced neutron spectra were verified through the calculation analyses by PHITS code.

Journal Articles

Detailed characterization of U-Co binary compounds

Matsuda, Tatsuma; Sugai, Takashi; Haga, Yoshinori; Yamamoto, Etsuji; Onuki, Yoshichika

Journal of the Physical Society of Japan, 80(Suppl.A), p.SA101_1 - SA101_3, 2011/07

Journal Articles

Possible long-periodic magnetic structure in SmPb$$_{3}$$

Ito, Takashi; Higemoto, Wataru; Ninomiya, Kazuhiko; Amato, A.*; Sugai, Takashi; Haga, Yoshinori; Suzuki, Hiroyuki*

Journal of the Physical Society of Japan, 80(Suppl.A), p.SA075_1 - SA075_3, 2011/07

A series of cubic SmX$$_3$$ (X=In, Sn, Pb) compounds has a $$Gamma_8$$ crystalline-electric-field ground state with various multipolar degrees of freedom. These show phase transitions at low temperatures and a possibility of multipolar ordering has been suggested. However, no microscopic experimental data is available so far and details of the ordered states have not been clarified yet. We performed muon spin relaxation measurements in order to elucidate nature of multipoles in these systems. A breaking of time-reversal symmetry was observed in all the ordered phases in zero applied field, indicating the primary order parameters are magnetic. We also obtained information about the ordered structures from a microscopic point of view.

Journal Articles

Identification of erythroid progenitors induced by erythropoietic activity in ${it Xenopus laevis}$

Kosaka, Nami*; Sugai, Tatsuhisa*; Nagasawa, Kazumichi*; Tanizaki, Yuta*; Meguro, Mizue; Aizawa, Yoichi*; Maekawa, Shun*; Adachi, Motoyasu; Kuroki, Ryota; Kato, Takashi

Journal of Experimental Biology, 214(6), p.921 - 927, 2011/03

 Times Cited Count:23 Percentile:68.66(Biology)

Oxygen is essential for the survival of animals. Red blood cells are responsible for transporting oxygen to tissues. We established a semi-solid colony forming assay, and showed that recombinant xlEPO induces erythroid colony formation in vitro and detected an increased level of erythropoietin activity in blood serum during acute anemic stress. In addition, the study demonstrated the possible presence of multiple, non-xlEPO, factors in anemic serum supportive of erythroid colony formation. These results indicate that erythropoiesis mediated by erythropoietin is present in amphibian species and, furthermore, that the regulatory mechanisms controlling peripheral erythrocyte number may vary among vertebrates.

Journal Articles

Incommensurate-to-commensurate magnetic phase transition in SmIn$$_3$$ observed by muon spin relaxation

Ito, Takashi; Higemoto, Wataru; Ninomiya, Kazuhiko; Luetkens, H.*; Sugai, Takashi; Haga, Yoshinori; Suzuki, Hiroyuki*

Journal of the Physical Society of Japan, 80(3), p.033710_1 - 033710_4, 2011/03

 Times Cited Count:4 Percentile:36.01(Physics, Multidisciplinary)

Magnetic susceptibility $$chi$$ and muon spin relaxation ($$mu$$SR) measurements are reported on SmIn$$_3$$ with a $$Gamma_8$$ ground state. Anomalies corresponding to successive phase transitions were observed in $$chi$$ at $$T_{rm I}sim$$16.5 K, $$T_{rm II}sim$$15.1 K, and $$T_{rm III}sim$$14.7 K. A spontaneous local magnetic field was detected below $$T_{rm I}$$ using the $$mu$$SR technique on the contrary to a pure quadrupolar ordering scenario proposed in the phase between $$T_{rm I}$$ and $$T_{rm II}$$. This result clearly indicates that the primary order parameters in all the ordered phases are magnetic. The local field distribution changes at around $$T_{rm II}$$ from a continuous broad one to a sharp one with decreasing temperature, suggesting that an incommensurate to commensurate magnetic phase transition takes place at this temperature. A possible magnetic structure in the ground state and importance of multipolar interactions are discussed.

Journal Articles

Single crystal growth and physical properties of ternary uranium compounds U$${M_2}$$Al$$_{10}$$ ($$M$$=Fe, Ru and Os)

Sugai, Takashi; Haga, Yoshinori; Matsuda, Tatsuma; Yamamoto, Etsuji; Tateiwa, Naoyuki; Honda, Fuminori*; Settai, Rikio*; Onuki, Yoshichika

Journal of Physics; Conference Series, 273, p.012122_1 - 012122_4, 2011/02

 Times Cited Count:0 Percentile:0.03

Journal Articles

Shielding experiments at high energy accelerators of Fermilab, 2; Spatial distribution measurement of reaction rate behind the shield and its application for Moyer model

Yashima, Hiroshi*; Kasugai, Yoshimi; Matsuda, Norihiro; Matsumura, Hiroshi*; Iwase, Hiroshi*; Kinoshita, Norikazu*; Mokhov, N.*; Leveling, A.*; Boehnlein, D.*; Vaziri, K.*; et al.

Progress in Nuclear Science and Technology (Internet), 1, p.48 - 51, 2011/02

The shielding experiment was performed at the anti-proton production target station in Fermi National Accelerator Laboratory. Aluminum, Bismath, Niobium, Copper and Indium samples were placed behind the shields. After irradiation, induced activities of samples were measured by using HPGe detector. The spatial distribution of reaction rate of samples which were placed behind the iron and concrete shields were obtained. The measured data shows that the reaction rates on the outer surfaces of the iron and concrete shields increases toward the downstream of the target. The obtained reaction rates were also fitted to Moyer's formula, and the attenuation lengths for iron and concrete shields were obtained.

Journal Articles

Shielding experiments at high energy accelerators of Fermilab, 4; Calculation analyses

Matsuda, Norihiro; Kasugai, Yoshimi; Matsumura, Hiroshi*; Yashima, Hiroshi*; Iwase, Hiroshi*; Kinoshita, Norikazu*; Sanami, Toshiya*; Mokhov, N.*; Leveling, A.*; Boehnlein, D.*; et al.

Progress in Nuclear Science and Technology (Internet), 1, p.57 - 60, 2011/02

The anti-proton (pbar) production target in Fermi National Accelerator Laboratory can be produced a wide variety of secondary particles including of anti-protons, by bombarding with protons accelerated to 120 GeV. The shielding experimental data, which was obtained around the pbar target, make possible to validate the accuracies of the general-purpose Monte Carlo simulation codes. In this paper, spatial distribution of reaction rates were calculated with two-dimensional (r-z) geometry simplified the real pbar target station using the PHITS, MARS and MCNPX code. These experimental data in iron shield were compared with the calculated data. The comparison for attenuation length of iron were good agreement between the experiments and calculations.

Journal Articles

Reconstruction of Holocene environmental changes in the Kiso-Ibi-Nagara compound river delta, Nobi Plain, central Japan, by diatom analyses of drilling cores

Saegusa, Yoshie*; Sugai, Toshihiko*; Ogami, Takashi*; Kashima, Kaoru*; Sasao, Eiji

Quaternary International, 230(1-2), p.67 - 77, 2011/01

 Times Cited Count:6 Percentile:22.08(Geography, Physical)

We reconstructed Holocene environmental changes by analyzing diatom assemblages of four drilling cores from the Nobi Plain, central Japan. We identified five diatom assemblage zones: (1) freshwater species dominant; (2) increase of marine and brackish-marine species, indicating transgression; (3) marine species dominant; (4) increase of freshwater species, indicating marine regression as a result of delta progradation; and (5) freshwater species dominant, in ascending order. It became clear that the shoreline migrated landward (transgression) faster than it migrated seaward (regression) by the comparison the diatom assemblages and lithological units. The transgressive diatom assemblage changes (decrease in marine-brackish water species) took up to 1000 years, whereas regressive changes required only a few hundred years. Diatom analysis is useful for reconstructing not only Holocene sea-level changes and sedimentary environments but also local geographic effects.

93 (Records 1-20 displayed on this page)