Extended X-ray absorption fine structure spectroscopy measurements and molecular dynamics simulations reveal the hydration structure of the radium(II) ion

Yamaguchi, Akiko; Nagata, Kojiro*; Kobayashi, Keita; Tanaka, Kazuya; Kobayashi, Toru; Tanida, Hajime; Shimojo, Kojiro; Sekiguchi, Tetsuhiro; Kaneta, Yui; Matsuda, Shohei; et al.

iScience (Internet), 25(8), p.104763_1 - 104763_12, 2022/08

https://doi.org/10.1016/j.isci.2022.104763

no abstracts in English

Optimizing TiO through water-soluble Ti complexes as raw material for controlling particle size and distribution of synthesized BaTiO nanocubes

Nakashima, Koichi*; Hironaka, Kota*; Ouchi, Kazuma*; Ajioka, Mao*; Kobayashi, Yoshio*; Yoneda, Yasuhiro; Yin, S.*; Kakihana, Masato*; Sekino, Toru*

ACS Omega (Internet), 6(48), p.32517 - 32527, 2021/12

https://doi.org/10.1021/acsomega.1c04013

The BaTiO nanoparticles synthesized by the hydrothermal method is examined by synchrotron X-ray and TEM observation. It was found that the particle size of synthesized BaTiO depends on the particle size of the raw material of TiO. Succeeded in synthesizing 100 nm size BaTiO nanocrystals showing uniform particle size distribution using TiO nanoparticles with optimized particle size. The obtained BaTiO nanocrystal is a tetragonal system of ferroelectric phase. A three-dimensional structure of BaTiO nanoparticles could be obtained by the electron beam tomography.

Hydration structures of barium ions; molecular dynamics simulations using the SCAN meta-GGA density functional and EXAFS spectroscopy studies

Yamaguchi, Akiko; Kobayashi, Keita; Takahashi, Yoshio*; Machida, Masahiko; Okumura, Masahiko

Chemical Physics Letters, 780, p.138945_1 - 138945_5, 2021/10

https://doi.org/10.1016/j.cplett.2021.138945

no abstracts in English

Local structure investigations of accumulated damage in irradiated MgAlO

Yoshioka, Satoru*; Tsuruta, Konosuke*; Yamamoto, Tomokazu*; Yasuda, Kazuhiro*; Matsumura, Sho*; Sugiyama, Takeharu*; Oba, Yojiro; Ishikawa, Norito; Kobayashi, Eiichi*; Okudaira, Koji*

Journal of the American Ceramic Society, 103(8), p.4654 - 4663, 2020/08

https://doi.org/10.1111/jace.17101

X-ray absorption near edge structure (XANES) and small-angle X-ray scattering (SAXS) reveal the damaged structures in MgAlO spinel induced by swift heavy ions. SAXS indicates the formation of ion tracks with cylindrical shape with a diameter of 5 nm. XANES indicates the cationic disordering between tetrahedral and octahedral sites by the irradiation. Quantitative analysis of XANES also reveals that cations preferably occupy the octahedral sites at high fluence.

X-ray absorption near edge structure and first-principles spectral investigations of cationic disorder in MgAlO induced by swift heavy ions

Yoshioka, Satoru*; Tsuruta, Konosuke*; Yamamoto, Tomokazu*; Yasuda, Kazuhiro*; Matsumura, Sho*; Ishikawa, Norito; Kobayashi, Eiichi*

Physical Chemistry Chemical Physics, 20(7), p.4962 - 4969, 2018/02

https://doi.org/10.1039/C7CP07591J

Cationic disorder in the MgAlO spinel induced by swift heavy ions was investigated using the X-ray absorption near edge structure. With changes in the irradiation fluences of 200 MeV Xe ions, the Mg K-edge and Al K-edge spectra were synchronously changed. The calculated spectra based on density function theory indicate that the change in the experimental spectra was due to cationic disorder between Mg in tetrahedral sites and Al in octahedral sites. These results suggest a high inversion degree to an extent that the completely random configuration is achieved in MgAlO induced by the high density electronic excitation under swift heavy ion irradiation.

Nondestructive elemental depth-profiling analysis by muonic X-ray measurement

Ninomiya, Kazuhiko*; Kubo, Kenya*; Nagatomo, Takashi*; Higemoto, Wataru; Ito, Takashi; Kawamura, Naritoshi*; Strasser, P.*; Shimomura, Koichiro*; Miyake, Yasuhiro*; Suzuki, Takao*; et al.

Analytical Chemistry, 87(9), p.4597 - 4600, 2015/05

https://doi.org/10.1021/acs.analchem.5b01169

Basic vacuum test of 500-kV photocathode DC gun components at KEK

Yamamoto, Masahiro*; Uchiyama, Takashi*; Miyajima, Tsukasa*; Honda, Yosuke*; Sato, Kotaro*; Matsuba, Shunya*; Saito, Yoshio*; Kobayashi, Masanori*; Kurisu, Hiriki*; Hajima, Ryoichi; et al.

Proceedings of 7th Annual Meeting of Particle Accelerator Society of Japan (DVD-ROM), p.717 - 720, 2010/08

http://www.pasj.jp/web_publish/pasj7/proceedings/P_4PM/P_EH_4PM/WEPS124.pdf

A 500-kV photocathode DC electron gun which can supply the beam of a low emittance and a high average current has been developed in collaboration with KEK, JAEA, Hiroshima Univ., Nagoya Univ. and Yamaguchi Univ. The vacuum of the gun chamber has to be lower Extreme High Vacuum for maintain cathode-life time. A titanium chamber and new material of ceramic were employed to reduce outgassing rate. The result of outgassing rate of the gun chamber is described in this report.

Status of the J-PARC RFQ

Hasegawa, Kazuo; Morishita, Takatoshi; Kondo, Yasuhiro; Oguri, Hidetomo; Kobayashi, Tetsuya; Naito, Fujio*; Yoshioka, Masakazu*; Matsumoto, Hiroshi*; Kawamata, Hiroshi*; Hori, Yoichiro*; et al.

Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (CD-ROM), p.693 - 695, 2010/03

http://www.pasj.jp/web_publish/pasj6/papers/tpopa03.pdf

The J-PARC RFQ (length 3.1m, 4-vane type, 324 MHz) accelerates a beam from the ion source to the DTL. The beam test of the linac was started in November 2006 and 181 MeV beam was successfully accelerated in January 2007. Since then, the linac has been delivered beams for commissioning of the linac itself, downstream accelerators and facilities. Trip rates of the RFQ, however, suddenly increased in Autumn 2008, and we are suffering from this issue for user run operation. We tried to recover by tender conditioning, modification of RF control, improvement of vacuum and so on. We manage to have beam operation. In this report, we describe the status of the RFQ.

Hydrogen adsorption on single-walled carbon nanotubes studied by core-level photoelectron spectroscopy and Raman spectroscopy

Tokura, Akio*; Maeda, Fumihiko*; Teraoka, Yuden; Yoshigoe, Akitaka; Takagi, Daisuke*; Homma, Yoshikazu*; Watanabe, Yoshio*; Kobayashi, Yoshihiro*

Carbon, 46(14), p.1903 - 1908, 2008/11

https://doi.org/10.1016/j.carbon.2008.07.041

We have investigated the adsorption of atomic hydrogen on vertically aligned carbon nanotube using synchrotron-radiation-based core-level photoelectron spectroscopy and Raman spectroscopy. From C1s spectra, we identified a peak component due to CH bonds of carbon atoms in single-walled carbon nanotubes. We also found the suppression of -plasmon excitation, indicating that the hydrogen adsorption deforms the bonding structure. Raman spectra of the single-walled carbon nanotubes indicated that the radial-breathing-mode intensities decreased due to the adsorption-induced bonding-structure deformation. Moreover, the decrease for single-walled carbon nanotubes with small-diameter was more severe than that for large-diameter. Our results strongly suggest that the hydrogen adsorption, which induces the structure deformation from sp to sp bonding, depends on the diameter of SWCNTs.

Report on the questionnaire about the data of atoms, molecules and atomic nuclei for medicine, 2004

Kobayashi, Toru*; Harata, Yasuo*; Matsufuji, Naruhiro*; Hasegawa, Tomoyuki*; Endo, Akira; Moribayashi, Kengo; Akahane, Keiichi*; Uehara, Shuzo*; Imahori, Yoshio*; Kato, Yo*; et al.

JAEA-Review 2006-002, 101 Pages, 2006/02

JAEA-Review-2006-002.pdf:5.53MB

This report provides an analysis of the results of the survey conducted among field experts regarding the data on atoms, molecules, and atomic nuclei used in medical applications. The important results are summarized as follows: First, the importance of the basic data for disciplines involved in medical research, i.e. physics and engineering, chemistry, pharmacology, biology, and the related data which are applied directly in medicine were identified. The related data are of greater importance in direct medical application compared to conventional basic data. Therefore, the data related to biology should be prepared in consideration of their convenient usage. Second, regarding the fundamental data on atoms, molecules and atomic nuclei related to medicine, the present data was able to approximately cope with the demands of many medical cases that needed data on quality, quantity, precision, etc. However, we found situations particularly in the IT community where comprehensively organized data was urgently needed. The data to be used for practical implementation must contain the specialized data for medical physics and biology. Finally, the significance of the continuity in the planned completion of the basic data was confirmed for the development of the associated fields. The expansion and completion of basic data should be done continuously and effectively while considering the limitation in resources and manpower.