Application of Bayesian estimation to X-ray fluorescent image

Matsuyama, Tsugufumi*; Igarashi, Momo*; Yasuda, Sora*; Murakami, Masashi; Yoshida, Yukihiko; Hayashi, Kazunori*; Machida, Masahiko; Tsuji, Koichi*

Analytical Chemistry, 9 Pages, 2024/01

http://dx.doi.org/10.2139/ssrn.4697562

Fundamental research of X-ray absorption imaging for elemental identification using a secondary target

Nakae, Masanori*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Machida, Masahiko; Tsuji, Koichi*

Advances in X-Ray Chemical Analysis, Japan, 54, p.89 - 99, 2023/03

Fundamental research on X-ray absorption imaging for elemental identification was studied. A secondary target was applied to obtain X-ray absorption images above and below the X-ray absorption edge of the target element. X-rays from an X-ray tube were irradiated to the secondary target, where the characteristic X-rays were emitted that were irradiated to the sample. X-ray absorption images were acquired with an exposure time of a few seconds with an X-ray camera. In this technique, it is difficult to change the energy of X-rays as we want, however we can apply this technique for imaging the specific element. Metal foil sample composed of Al, Cu, and Ni was analyzed. To obtain an X-ray elemental image of Ni, two X-ray absorption images were taken using the X-rays above and below the Ni K-edge. X-rays of Cu K and Zn K were prepared by using Cu and Zn plates as the secondary target. Finally, the Ni elemental image was obtained by subtracting two images. Furthermore, the X-ray camera had a function of setting critical energies for imaging, thus it was demonstrated that an X-ray elemental image of Ni was obtained using a single secondary target without changing the secondary target.

Development and evaluation of XRF imaging instrument for moving objects

Fuchita, Tomoki*; Urata, Taisei*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Ueda, Akihiko; Machida, Masahiko; Sasaki, Toshiki; Tsuji, Koichi*

Advances in X-Ray Chemical Analysis, Japan, 53, p.77 - 87, 2022/03

X-ray fluorescence (XRF) analysis is an analytical method to obtain elemental information by detecting fluorescence X-rays emitted from a sample irradiated with X-rays. It is possible to obtain two-dimensional elemental distribution images by scanning a sample with micro X-ray beam. In this study, we developed an XRF analytical instrument to rapidly obtain the elemental distributions for moving samples on a belt conveyor by applying the micro XRF technique. X-rays were widely irradiated to the belt conveyor. The elemental distributions were measured by scanning an X-ray detector, crossing above the belt conveyor. A collimator was attached to the top of the detector to limit the analyzing area. Both detection limit and spatial resolutions for moving directions of the detector and the belt conveyor were evaluated. Finally, it was demonstrated that the multi-elemental imaging was possible with the developed XRF instrument.

Conceptual study of a plutonium burner high temperature gas-cooled reactor with high nuclear proliferation resistance

Goto, Minoru; Demachi, Kazuyuki*; Ueta, Shohei; Nakano, Masaaki*; Honda, Masaki*; Tachibana, Yukio; Inaba, Yoshitomo; Aihara, Jun; Fukaya, Yuji; Tsuji, Nobumasa*; et al.

Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.507 - 513, 2015/09

A concept of a plutonium burner HTGR named as Clean Burn, which has a high nuclear proliferation resistance, had been proposed by Japan Atomic Energy Agency. In addition to the high nuclear proliferation resistance, in order to enhance the safety, we propose to introduce PuO-YSZ TRISO fuel with ZrC coating to the Clean Burn. In this study, we conduct fabrication tests aiming to establish the basic technologies for fabrication of PuO-YSZ TRISO fuel with ZrC coating. Additionally, we conduct a quantitative evaluation of the security for the safety, a design of the fuel and the reactor core, and a safety evaluation for the Clean Burn to confirm the feasibility. This study is conducted by The University of Tokyo, Japan Atomic Energy Agency, Fuji Electric Co., Ltd., and Nuclear Fuel Industries, Ltd. It was started in FY2014 and will be completed in FY2017, and the first year of the implementation was on schedule.

Ligand field analysis of ruthenium nitrosyl complexes using DFT calculation combined with Ru Mssbauer isomer shift

Kaneko, Masashi; Kato, Akane*; Nakashima, Satoru*; Kitatsuji, Yoshihiro

no journal, , 

A linear relationship between Mssbauer isomer shift values and electron densities at nucleus position assures the quantitative evaluation of the covalent interaction between a Mssbauer element and its surroundings. The use of this linear relationship makes us to predict a covalency in unknown compounds by electron density analysis based on quantum chemical calculations. As the first step to elucidate stability of ruthenium, which is known to be one of obstructive factors for separation process of high-level radioactive waste, in this study, we performed a fundamental investigation to predict the chemical bonding properties of nitrosylruthenium complexes. We modeled several nitrosylruthenium complexes with basic ligands, such chloride ion and ammonia, namely, [Ru(NO)L] (L = Br, Cl, NH, CN), by density functional calculation and estimated Ru Mssbauer isomer shifts by electron density analysis. The calculated results reproduced the experimental metal-ligand bond lengths and Mssbauer isomer shifts within the error of 0.1 mm/s. We also calculated the orbital splitting values of Ru d-electron. The value increased in the order of L = Br, Cl, NH, CN and correlated to that of Mssbauer isomer shift values. This indicated that the covalent interation between metal and ligand originates in the d-electron contribution of ruthenium to the coordination bonds.

Fundamental study for elemental identification method by X-ray absorption imaging using a secondary target

Nakae, Masanori*; Matsuyama, Tsugufumi*; Murakami, Masashi; Yoshida, Yukihiko; Machida, Masahiko; Ueda, Akihiko; Sasaki, Toshiki; Tsuji, Koichi*

no journal, , 

X-ray absorption imaging is a technique in which samples are irradiated with X-rays and the transmitted X-rays are detected by an X-ray camera. Although this method is non-destructive and fast, X-ray cameras generally do not have energy resolution and cannot identify elements. Recently, an X-ray imaging method has been reported to use synchrotron radiation to image the elemental distribution using X-rays with energy around the absorption edge, and analyze the difference between the images. However, it is difficult to change the energy of X-rays in a laboratory. In this study, we studied the method for visualization of only the target element even in the laboratory by using a secondary target and an X-ray filter.

Development of mutual separation process of An/Ln, 1; An/Ln separation process without addition of alkali solution

Sasaki, Yuji; Matsumiya, Masahiko*; Kaneko, Masashi*; Kitatsuji, Yoshihiro; Ban, Yasutoshi; Kumagai, Yuta

no journal, , 

We have been developing an effective separation method for actinides (An) and lanthanides (Ln) for the establishment of a nuclear fuel cycle. According to worldwide studies, decontamination factors for An/Ln exceeding 1000 have been achieved using 20 stages of extraction. Therefore, the Japanese separation method should aim to meet these performance levels. The TODGA-DTBA method developed in our laboratory achieves a decontamination factor of over 143 (Am/Sm) through batchwise extraction using 18 organic-phase stages and 20 aqueous-phase stages. However, this method requires DTBA to be in its dissociated form and thus necessitates pH control at approximately 1.3 using an alkaline solution (ethylenediamine). In this study, we re-investigate separation conditions without the use of an alkaline solution. Besides DTBA, we employ water-soluble neutral donors, TEDGA and DOODA. The present results show that the separation factor for Am/Nd is several times higher than that (approximately 10) obtained under the TODGA-DTBA conditions.

Electrolytic reduction of Mo and W as lighter homologues of seaborgium

Toyoshima, Atsushi; Miyashita, Sunao*; Oe, Kazuhiro*; Kitayama, Yuta*; Lerum, H. V.*; Goto, Naoya*; Kaneya, Yusuke; Komori, Yukiko*; Mitsukai, Akina*; Vascon, A.; et al.

no journal, , 

no abstracts in English

Developments towards aqueous phase chemistry of transactinide elements

Toyoshima, Atsushi; Oe, Kazuhiro*; Asai, Masato; Attallah, M. F.*; Goto, Naoya*; Gupta, N. S.*; Haba, Hiromitsu*; Kaneko, Masashi*; Kaneya, Yusuke; Kasamatsu, Yoshitaka*; et al.

no journal, , 

Due to short half-lives less than 10 s and extremely low production rates, transactinide elements heavier than seaborgium (Sg) are produced on an atom per hour scale. Therefore, a continuous rapid chemistry assembly is required to study aqueous-phase chemistry of these heaviest elements. In the present study, we started developments of a continuous chemistry assembly. Our first attempt was made in on-line experiments with Mo and W, lighter homologs of Sg, to optimize a chemistry assembly consisting of a newly developed membrane degasser as an interface between gas-jet and aqueous phase, a flow electrolytic column apparatus utilized to control oxidation states of Mo and W ions, and the continuous liquid-liquid extraction apparatus of SISAK for separation. In the conference, present status of the developments will be presented.

Development of a H measurement method for radioactive waste analysis

Kumagai, Yuta; Kawai, Masashi*; Ikarugi, Riko; Oka, Toshitaka; Toigawa, Tomohiro; Kitatsuji, Yoshihiro; Kumagai, Jun*

no journal, , 

We have developed a highly sensitive H analysis method by employing a gas chromatograph with a senser diode, aiming to apply for small amounts of H production from radioactive wastes. The H analysis method was tested with an X-ray irradiation experiment of NaWO 2HO. Even though the absorbed dose was less than 100 Gy, the H production from only 1 g of the sample can be analyzed by our method. Based on the experimental results, the lower limit of H quantification was evaluated to be 2 10 mol.