Development of nondestructive elemental analysis system for Hayabusa2 samples using muonic X-rays

Osawa, Takahito; Nagasawa, Shunsaku*; Ninomiya, Kazuhiko*; Takahashi, Tadayuki*; Nakamura, Tomoki*; Wada, Taiga*; Taniguchi, Akihiro*; Umegaki, Izumi*; Kubo, Kenya*; Terada, Kentaro*; et al.

ACS Earth and Space Chemistry (Internet), 7(4), p.699 - 711, 2023/04

https://doi.org/10.1021/acsearthspacechem.2c00303

The concentrations of carbon and other major elements in asteroid samples provide very important information on the birth of life on the Earth and the solar-system evolution. Elemental analysis using muonic X-rays is one of the best analytical methods to determine the elemental composition of solid materials, and notably, is the only method to determine the concentration of light elements in bulk samples in a non-destructive manner. We developed a new analysis system using muonic X-rays to measure the concentrations of carbon and other major elements in precious and expectedly tiny samples recovered from the asteroid Ryugu by spacecraft Hayabusa2. Here we report the development process of the system in 4 stages and their system configurations, The analysis system is composed of a stainless-steel analysis chamber, an acrylic glove box for manipulating asteroid samples in a clean environment, and Ge semiconductor detectors arranged to surround the analysis chamber. The performance of the analysis system, including the background level, which is crucial for the measurement, was greatly improved from the first stage to the later ones. Our feasibility study showed that the latest model of our muonic X-ray analysis system is capable of determining the carbon concentration in Hayabusa2's sample model with an uncertainty of less than 10 percent in a 6-day measurement.

Role of filamentous fungi in migration of radioactive cesium in the Fukushima forest soil environment

Onuki, Toshihiko; Sakamoto, Fuminori; Kozai, Naofumi; Namba, Kenji*; Neda, Hitoshi*; Sasaki, Yoshito; Niizato, Tadafumi; Watanabe, Naoko*; Kozaki, Tamotsu*

Environmental Science; Processes & Impacts, 21(7), p.1164 - 1173, 2019/07

https://doi.org/10.1039/C9EM00046A

The fate of radioactive Cs deposited after the Fukushima nuclear power plant accident and its associated radiological impacts are largely dependent on its mobility from surface soils to forest ecosystems. We measured the accumulation of radioactive Cs in the fruit bodies of wild fungi in the forest at Iidate, Fukushima, Japan. The transfer factors (TFs) of radioactive Cs from soil to the fruit bodies of wild fungi were between 10 to 10, a range similar to those reported for the fruit bodies collected in Europe after the Chernobyl accident and in parts of Japan contaminated by nuclear bomb test fallout. Comparison of the TFs of the wild mushroom and that of the fungal hyphae of 704 stock strains grown on agar medium containing nutrients and radioactive Cs showed that the TFs of wild mushroom were lower. TF was less than 0.1 after addition of the minerals zeolite, vermiculite, phlogopite, smectite, or illite of 1% weight to the agar medium. These results indicate that the presence of minerals decrease Cs uptake by fungi grown in the agar medium.

Root endophytic bacteria of a Cs and Mn accumulator plant, , increase Cs and Mn desorption in the soil

Yamaji, Keiko*; Nagata, Satoshi*; Haruma, Toshikatsu*; Onuki, Toshihiko; Kozaki, Tamotsu*; Watanabe, Naoko*; Namba, Kenji*

Journal of Environmental Radioactivity, 153, p.112 - 119, 2016/03

https://doi.org/10.1016/j.jenvrad.2015.12.015

Of the 463 strains that we isolated, 107 (23.1%) produced the siderophores. We found Cs and Mn desorption concomitant with Al and Fe desorption. These results suggest that root endophytes of Cs accumulator plant produce siderophores, resulting in the desorption of Cs from the contaminated soil collected at Fukushima, Japan.

Interdisciplinary approach to improve and systematize the investigation and evaluation techniques on geological environment in relation to radioactive waste repository; Japanese fiscal year, 2010 (Contract research)

Kojima, Keiji*; Onishi, Yuzo*; Watanabe, Kunio*; Nishigaki, Makoto*; Tosaka, Hiroyuki*; Shimada, Jun*; Aoki, Kenji*; Tochiyama, Osamu*; Yoshida, Hidekazu*; Ogata, Nobuhisa; et al.

JAEA-Research 2011-033, 126 Pages, 2012/02

JAEA-Research-2011-033.pdf:31.33MB

The next advancements for the research of radioactive waste repository was started to improve and systematize the investigation and evaluation techniques on geological environment in consideration of intra-field of science and technology. Intra-field means the various fields among each study area of (a) geological environment, (b) design and engineering, (c) safety evaluation for radioactive waste repository, here. The following items were studied and discussed this year. (1) To Reconstruct Near Field (NF) Concept in consideration of coupled phenomena on geological environment. (2) To develop systematic investigation techniques on the geological environment in consideration of intra-field among each study area above mentioned (a), (b) and (c). Regarding (1), examination of NF concept focused on the realistic crystalline rock was carried out. Also through the overall discussion in the committee, comments from the all commissioners in relation to the intra-field of their study area were made to reflect on reconstruction of NF concept. Regarding (2), the research and development in consideration of NF and intra-field among each study area were conducted.

Construction of cERL cryomodules for injector and main linac

Umemori, Kensei*; Furuya, Takaaki*; Kako, Eiji*; Noguchi, Shuichi*; Sakai, Hiroshi*; Sato, Masato*; Shishido, Toshio*; Watanabe, Ken*; Yamamoto, Yasuchika*; Shinoe, Kenji*; et al.

Proceedings of 15th International Conference on RF Superconductivity (SRF 2011) (Internet), p.956 - 961, 2011/07

http://accelconf.web.cern.ch/AccelConf/SRF2011/papers/frioa06.pdf

The Compact ERL (cERL) project is advanced in Japan. Its aim is to demonstrate the circulation of 100 mA electron beams with energy of 35-200 MeV. Superconducting cavities are key components for realizing ERL and used for injector part and main linac part. Critical issue for the injector part is the development of input power coupler. Prototype input couplers were fabricated and high power test was performed. Cooling ability of HOM coupler is also important for CW operation of cavity. At main linac part, HOM damped 9-cell cavities are applied to avoid BBU instabilities. Prototypes were fabricated for the cavity, the input coupler and the HOM absorber. Their performance was investigated. For both parts, cryomodules are under construction and will be completed in 2012.

Study on systemizing of technology for investigation and analysis of the deep underground geological environment; Japanese fiscal year, 2009 (Contract research)

Kojima, Keiji*; Onishi, Yuzo*; Watanabe, Kunio*; Nishigaki, Makoto*; Tosaka, Hiroyuki*; Shimada, Jun*; Aoki, Kenji*; Tochiyama, Osamu*; Yoshida, Hidekazu*; Ogata, Nobuhisa; et al.

JAEA-Research 2010-049, 282 Pages, 2011/02

JAEA-Research-2010-049.pdf:29.88MB

This report summarizes studies that have been carried out with the aim of assessing and systemizing the technology used for the investigation and analysis of the deep underground geological environment in relation to the disposal of radioactive waste. The main studies were: (1) a study on the research and development (R&D) topics proven to have practical application for the investigation, and analysis and understanding of the deep underground geological environment, and, (2) a study on leading edge technology that can provide the advanced technical basis for the investigation, analysis and understanding of the deep underground geological environment. Regarding the R&D topics (1, above), specific investigations, measurements, numerical analyses and chemical analyses were performed and reviewed with respect to the topics, (a) Repository design, engineering technology (b) Geological environment and (c) Safety evaluation. Based on the result of the review, topics requiring collaboration research in overlapping research fields, including safety assessment, were identified. Also, the near field concept (NFC) was reconsidered in terms of its realistic construction model. Regarding advanced technology (2, above), based on the objectives of the JAEA (Japan Atomic Energy Agency) research project, the study was implemented considering previous R&D results and detailed research result at the research site and thus an assessment of the need for advanced technical basis for investigation and analysis. This study contributed to the R&D development and its practical application.

Study on systemizing of technology for investigation and analysis of the deep underground geological environment; Japanese fiscal year 2008 (Contract research)

Kojima, Keiji*; Onishi, Yuzo*; Watanabe, Kunio*; Nishigaki, Makoto*; Tosaka, Hiroyuki*; Shimada, Jun*; Aoki, Kenji*; Tochiyama, Osamu*; Yoshida, Hidekazu*; Ogata, Nobuhisa; et al.

JAEA-Research 2009-055, 145 Pages, 2010/02

JAEA-Research-2009-055.pdf:55.53MB

This report summarizes studies that were carried out with the aim of assessing and systemizing the technology used for the investigation and analysis of the deep underground geological environment in relation to the disposal of radioactive waste. The main studies were: (1) a study on the research and development (R&D) topics proven to have practical application for the investigation, analysis and understanding of the deep underground geological environment, and, (2) a study on leading edge technology that can provide the advanced technical basis for the investigation, analysis and understanding of the deep underground geological environment. The principal results obtained from the studies are as follows: Regarding the R&D topics (1, above), the specific investigations, measurements, numerical and chemical analyses were reviewed with respect to engineering technology and the geological environment in this year. Based on the results of the review, topics requiring collaboration research in overlapping research fields, including safety assessment, were identified. Also, the near field concept (NFC) was reconsidered in terms of both the generic model and for crystalline rock. Regarding advanced technology (2, above), based on the objectives of the JAEA (Japan Atomic Energy Agency) research project, the study was implemented considering previous R&D results and detailed research result at the research site and thus an assessment of the need for advanced technical basis for investigation and analysis. This study contributed to the R&D development and its practical application.

Study on systemizing technology on investigation and analysis of deep underground geological environment; Japanese fiscal year, 2007 (Contract research)

Kojima, Keiji*; Onishi, Yuzo*; Watanabe, Kunio*; Nishigaki, Makoto*; Tosaka, Hiroyuki*; Shimada, Jun*; Aoki, Kenji*; Tochiyama, Osamu*; Yoshida, Hidekazu*; Ogata, Nobuhisa; et al.

JAEA-Research 2008-099, 171 Pages, 2009/03

JAEA-Research-2008-099-1.pdf:28.65MB
JAEA-Research-2008-099-2.pdf:49.14MB

In this year, the following studies were carried out with the aim of systemizing the technology on the investigation and analysis to understand the deep underground geological environment in relation to the radioactive waste disposal. (1) The study on the research and development (R&D) subjects which turned to the practical investigation and analysis of deep underground geological environment. (2) The study on the advanced technical basis for the investigation and analysis of deep underground geological environment. The results obtained from the studies are as follows: Regarding (1), the specific investigations, measurements, numerical and chemical analyses were performed particularly for research subjects: (a) the repository design and engineering technology and (b) geological environment. Based on the results on (1), (c) tasks of collaboration research on niche area between the research fields, including the safety assessment field, were selected. Also subject's items of the NFC (Near Field Concept) redefinition were discussed. Regarding (2), based on the extraction tasks of JAEA (Japan Atomic Energy Agency) research project, the study was implemented with applying previous R&D results and detailed research at the research field was carried out. This study contributed to the R&D development for its practical application.

Measurement of the paint magnets for the beam painting injection system in the J-PARC 3-GeV RCS

Takayanagi, Tomohiro; Kanazawa, Kenichiro; Ueno, Tomoaki; Someya, Hirohiko*; Harada, Hiroyuki*; Irie, Yoshiro; Kinsho, Michikazu; Yamazaki, Yoshishige; Yoshimoto, Masahiro; Kamiya, Junichiro; et al.

IEEE Transactions on Applied Superconductivity, 18(2), p.310 - 313, 2008/06

https://doi.org/10.1109/TASC.2008.920771

The beam painting injection system of the 3-GeV RCS in J-PARC, which realizes the uniform beam distributions in the ring, consists of four horizontal paint bump magnets and two vertical paint magnets. Each paint bump magnet power supply is required to excite the current with high accuracy that varies from 17.6 kA to zero during 0.5 msec. The IGBT chopper units, the switching frequency of which is 50 kHz each, are multiple connected to achieve the effective carrier frequency of 600 kHz. The output accuracy is then achieved to be less than 1 %. The measurements of the magnetic field with the actual current waveform were performed and the good performance was confirmed.

Design and construction of septum magnets at 3-GeV RCS in J-PARC

Yoshimoto, Masahiro; Ueno, Tomoaki; Togashi, Tomohito; Takeda, Osamu; Kanazawa, Kenichiro; Watanabe, Masao; Yamazaki, Yoshio; Kamiya, Junichiro; Takayanagi, Tomohiro; Kuramochi, Masaya; et al.

IEEE Transactions on Applied Superconductivity, 18(2), p.297 - 300, 2008/06

https://doi.org/10.1109/TASC.2008.922282