Recent status of the cryogenic sample environment at the MLF, J-PARC

Ishikado, Motoyuki*; Takahashi, Ryuta*; Yamauchi, Yasuhiro*; Nakamura, Masatoshi*; Ishimaru, Sora*; Yamauchi, Sara*; Kawamura, Seiko; Kira, Hiroshi*; Sakaguchi, Yoshifumi*; Watanabe, Masao; et al.

JPS Conference Proceedings (Internet), 41, p.011010_1 - 011010_7, 2024/05

https://doi.org/10.7566/JPSCP.41.011010

Space weather benchmarks on Japanese society

Ishii, Mamoru*; Shiota, Daiko*; Tao, Chihiro*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Ishii, Takako*; Ichimoto, Kiyoshi*; Kataoka, Ryuho*; Koga, Kiyokazu*; Kubo, Yuki*; et al.

Earth, Planets and Space (Internet), 73(1), p.108_1 - 108_20, 2021/12

https://doi.org/10.1186/s40623-021-01420-5

We surveyed the relationship between the scale of space weather events and their occurrence rate in Japan and we discussed the social impact of these phenomena during the Project for Solar-Terrestrial Environment Prediction (PSTEP). The information was compiled for domestic users of space weather forecasts for appropriate preparedness against space weather disasters. This paper gives a comprehensive summary of the survey, focusing on the fields of electricity, satellite operations, communication and broadcasting, satellite positioning usage, aviation, human space activity, and daily life on the Earth's surface, using the cutting-edge knowledge of space weather. Quantitative estimations of the economic impact of space weather events on electricity and aviation are also given.

Hydrological and climate changes in southeast Siberia over the last 33 kyr

Katsuta, Nagayoshi*; Ikeda, Hisashi*; Shibata, Kenji*; Kokubu, Yoko; Murakami, Takuma*; Tani, Yukinori*; Takano, Masao*; Nakamura, Toshio*; Tanaka, Atsushi*; Naito, Sayuri*; et al.

Global and Planetary Change, 164, p.11 - 26, 2018/05

https://doi.org/10.1016/j.gloplacha.2018.02.012

Paleoenvironmental and paleoclimate changes in Siberia were reconstructed by continuous, high-resolution records of chemical compositions from a sediment core retrieved from the Buguldeika Saddle, Lake Baikal, dating back to the last 33 cal. ka BP. The Holocene climate followed by a shift at ca. 6.5 cal. ka BP toward warm and dry, suggesting that the climate system transition from the glacial to interglacial state occurred. In the last glacial period, the deposition of carbonate mud from the Primorsky Range was associated with Heinrich events (H3 and H1) and the Selenga River inflow was caused by meltwater of mountain glaciers in the Khamar-Daban Range. The anoxic bottom-water during Allerod-Younger Dryas was probably a result of weakened ventilation associated with reduced Selenga River inflow and microbial decomposition of organic matters from the Primorsky Range. The rapid decline in precipitation during the early Holocene may have been a response to the 8.2 ka cooling event.

Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex, 3; Neutron devices and computational and sample environments

Sakasai, Kaoru; Sato, Setsuo*; Seya, Tomohiro*; Nakamura, Tatsuya; To, Kentaro; Yamagishi, Hideshi*; Soyama, Kazuhiko; Yamazaki, Dai; Maruyama, Ryuji; Oku, Takayuki; et al.

Quantum Beam Science (Internet), 1(2), p.10_1 - 10_35, 2017/09

https://doi.org/10.3390/qubs1020010

Neutron devices such as neutron detectors, optical devices including supermirror devices and He neutron spin filters, and choppers are successfully developed and installed at the Materials Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC), Tokai, Japan. Four software components of MLF computational environment, instrument control, data acquisition, data analysis, and a database, have been developed and equipped at MLF. MLF also provides a wide variety of sample environment options including high and low temperatures, high magnetic fields, and high pressures. This paper describes the current status of neutron devices, computational and sample environments at MLF.

Development of in-pile instruments for fuel and material irradiation tests

Shibata, Akira; Kitagishi, Shigeru; Kimura, Nobuaki; Saito, Takashi; Nakamura, Jinichi; Omi, Masao; Izumo, Hironobu; Tsuchiya, Kunihiko

JAEA-Conf 2011-003, p.185 - 188, 2012/03

https://jopss.jaea.go.jp/pdfdata/JAEA-Conf-2011-003.pdf#page=195

To get measurement data with high accuracy for fuel and material behavior studies in irradiation tests, two kinds of measuring equipments have been developed; these are the Electrochemical Corrosion Potential (ECP) sensor, the Linear Voltage Differential Transformer (LVDT) type gas pressure gauge. The ECP sensor has been developed to determine the corrosive potential under high temperature and high pressure water condition. The structure of the joining parts was optimized to avoid stress concentration. The LVDT type gas pressure gauge has been developed to measure gas pressure in a fuel element during neutron irradiation. To perform stable measurements with high accuracy under high temperature, high pressure and high dosed environment, the coil material of LVDT was changed to MI cable. As a result of this development, the LVDT type gas pressure gauge showed high accuracy at 1.8% of a full scale, and good stability.

Establishment of experimental equipments in irradiation technology development building

Ishida, Takuya; Tanimoto, Masataka; Shibata, Akira; Kitagishi, Shigeru; Saito, Takashi; Omi, Masao; Nakamura, Jinichi; Tsuchiya, Kunihiko

JAEA-Testing 2011-001, 44 Pages, 2011/06

JAEA-Testing-2011-001.pdf:4.52MB

The Neutron Irradiation and Testing Reactor Center has developed new irradiation technologies to provide irradiation data with high technical value for the refurbishment and resume of the Japan Materials Testing Reactor (JMTR). For the purpose to perform assembling of capsules, materials tests, materials inspection and analysis of irradiation specimens for the development of irradiation capsules, improvement and maintenance of facilities were performed. The RI application development building was refurbished and maintained for above-mentioned purpose. After refurbishment, the building was named Irradiation Technology Development Building. It contains eight laboratories based on the purpose of use, and experimental apparatuses were installed. This report describes the refurbishment work of the RI application development building, the installation work and operation method of the experimental apparatuses and the basic management procedure of the Irradiation Technology Development Building.

Halo structure of the island of inversion nucleus Ne

Nakamura, Takashi*; Kobayashi, Nobuyuki*; Kondo, Yosuke*; Sato, Yoshiteru*; Aoi, Nori*; Baba, Hidetada*; Deguchi, Shigeki*; Fukuda, Naoki*; Gibelin, J.*; Inabe, Naoto*; et al.

Physical Review Letters, 103(26), p.262501_1 - 262501_4, 2009/12

https://doi.org/10.1103/PhysRevLett.103.262501

no abstracts in English

Isotope fractionation due to sedimentation of atoms in centrifuged indium-lead alloy

Ono, Masao; Iguchi, Yusuke*; Okayasu, Satoru; Esaka, Fumitaka; Kobayashi, Katsura*; Hao, T.; Bagum, R.*; Osawa, Takahito; Fujii, Kimio; Nakamura, Eizo*; et al.

Defect and Diffusion Forum, 289-292, p.63 - 68, 2009/04

The atomic-scale graded structure of In-Pb alloy was formed by an ultracentrifuge experiment under conditions that a gravitational field of 0.8110 G for 100 hours at 150 C in solid state in our previous study. The isotope ratio measurements were performed on the centrifuged sample with secondary ion mass spectrometer (SIMS). Pb/Pb and Pb/Pb isotope ratio changed with negative gradient in the direction of centrifugal force approximately 1.5% and 0.8%, respectively. And three-isotope diagram of Pb/Pb versus Pb/Pb proved that the isotope fluctuation depends on isotopic mass difference. These results showed that the strong gravitational field not only affected on the inter-diffusion but also on self-diffusion in this alloy as causing isotope fractionation effect, and the isotope fractionation was dependent on mass-difference.

Performance measurement of the SOF detector for boron neutron capture therapy

Komeda, Masao; Kumada, Hiroaki; Ishikawa, Masayori*; Nakamura, Takemi; Yamamoto, Kazuyoshi; Matsumura, Akira*

Proceedings of 13th International Congress on Neutron Capture Therapy (ICNCT-13) (CD-ROM), 3 Pages, 2008/11

In this report, deterioration of a SOF detector that can measure thermal neutron in real time was investigated in irradiation experiments. Sensitivity of a SOF detector decreased by 2.0% after an irradiation of about 4 hours. Then thermal neutron fluence was approximately 2.010 (n/cm). And after the SOF detector was used for about 2 months, sensitivity decreased to 42%. Then thermal neutron fluence was approximately 6.410 (n/cm). Supposing that thermal neutron fluence is 210 (n/cm) on the surface of a patient at a BNCT, sensitivity of a SOF detector is considered to be decreased by approximately 0.3% at a BNCT. Therefore it is considered that countermeasure against deterioration is necessary for using a SOF detector at BNCT in the future.

Isotope fluctuation in indium-lead alloy induced by solid centrifugation

Ono, Masao; Iguchi, Yusuke*; Okayasu, Satoru; Esaka, Fumitaka; Kobayashi, Katsura*; Hao, T.; Bagum, R.*; Osawa, Takahito; Fujii, Kimio; Nakamura, Eizo*; et al.

Journal of Nuclear Science and Technology, 45(Suppl.6), p.108 - 110, 2008/09

https://doi.org/10.1080/00223131.2008.10875989

The atomic-scale graded structure of In-Pb alloy was formed by an ultracentrifuge experiment under conditions that a gravitational field of 810,000 G for 100 hours at 150C (solid state) in our previous study. The isotope fluctuation on this sample was measured using secondary ion mass spectrometer (SIMS). The ratio both Pb/Pb and In/In changed with positive gradient in the direction of centrifugal force approximately 1.2%. These isotope fluctuations were larger than that of starting state of natural state (In0.2%, Pb0.1%). These show that the sedimentation of isotopes occurred by solid centrifugation in this alloy, although achieved concentration gradients were small.