Microstructure distribution of Japanese sword cross sections analyzed by the diffractometer TAKUMI at J-PARC

Oikawa, Kenichi; Harjo, S.; Pham, A. H.*; Kawasaki, Takuro; Morito, Shigekazu*; Kiyanagi, Yoshiaki*; Shinohara, Takenao; Kai, Tetsuya; Oba, Takuya*; Ito, Masakazu*

JPS Conference Proceedings (Internet), 33, p.011062_1 - 011062_6, 2021/03

https://doi.org/10.7566/JPSCP.33.011062

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.

Fluorine analysis of human enamel around fluoride-containing materials under different pH-cycling by -PIGE/PIXE system

Komatsu, Hisanori*; Yamamoto, Hiroko*; Matsuda, Yasuhiro*; Kijimura, Taiki*; Kinugawa, Michihiko*; Okuyama, Katsushi*; Nomachi, Masaharu*; Yasuda, Keisuke*; Sato, Takahiro; Oikawa, Masakazu*

Nuclear Instruments and Methods in Physics Research B, 269(20), p.2274 - 2277, 2011/10

https://doi.org/10.1016/j.nimb.2011.02.042

Quick change of ion species of heavy-ion microbeam by cocktail beam acceleration technique with the JAEA AVF cyclotron

Kurashima, Satoshi; Yoshida, Kenichi; Oikawa, Masakazu*; Sato, Takahiro; Miyawaki, Nobumasa; Yuyama, Takahiro; Okumura, Susumu; Kashiwagi, Hirotsugu; Ishibori, Ikuo; Nara, Takayuki; et al.

Nuclear Instruments and Methods in Physics Research B, 267(12-13), p.2024 - 2027, 2009/06

https://doi.org/10.1016/j.nimb.2009.03.083

A heavy-ion microbeam with energy of hundreds of MeV is utilized for research in biotechnology and materials science at the JAEA AVF cyclotron facility. Beam users need microbeams providing a wide range of linear energy transfer (LET). In order to vary LET widely, we have to change the ion species and/or energy. A cocktail beam acceleration technique is frequently used to change the ion species quickly. Ion species and energy can be changed by slightly shifting the acceleration frequency. The cocktail acceleration technique has been applied to microbeam production for quick change of ion species of a microbeam. As a result, we have succeeded to reduce considerably microbeam changing time to within 30 minutes between a 260 MeV Ne and a 520 MeV Ar. No deterioration of a microbeam spot size has been confirmed using a secondary electron microscope image of a copper mesh.

Transient current mapping obtained from silicon photodiodes using focused ion microbeams with several hundreds of MeV

Hirao, Toshio; Onoda, Shinobu; Oikawa, Masakazu*; Sato, Takahiro; Kamiya, Tomihiro; Oshima, Takeshi

Nuclear Instruments and Methods in Physics Research B, 267(12-13), p.2216 - 2218, 2009/06

https://doi.org/10.1016/j.nimb.2009.03.051

Single-Event Effects (SEEs) are triggered when an energetic heavy ion traverses a sensitive area in electric devices. Since the SEEs occur due to dense charge which is created along to ion track within the order of picoseconds, the measurement of such a high speed current signals is very important. Furthermore, the size of dense charge and their concentration depend on LET as well as energy of incident ions. This means that the transient currents induced in electronic devices by incidence of ions with various energies and LETs should be investigated to clarify the mechanism of SEEs for electronic devices. Especially, the evaluations using heavy ions with high energies more than a several hundred MeVs are very important to understand the mechanism of SEEs observed in space. For this aim, we have developed an irradiation system of focused heavy ion microbeams at a several hundreds of MeVs at JAEA. In this paper, we study transient currents induced in Si photodiodes using the focused heavy ion microbeam irradiation system. The mapping of charge collected from the photodiodes irradiated with 260 MeV Ne ion microbeams, which is firstly observed in the world, will be presented. In addition, the difference in transient currents induced by ions at several hundred MeVs from ions at tens MeVs is discussed using TCAD (Technology Computer Aided Design) and GUN theorem.

Characteristics of focusing high-energy heavy ion microbeam system at the JAEA AVF cyclotron

Oikawa, Masakazu*; Sato, Takahiro; Kamiya, Tomihiro; Kurashima, Satoshi; Okumura, Susumu; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Fukuda, Mitsuhiro*; Sakai, Takuro; Yokota, Wataru

Applied Radiation and Isotopes, 67(3), p.484 - 487, 2009/03

https://doi.org/10.1016/j.apradiso.2008.06.025

no abstracts in English

Fast single-ion hit system for heavy-ion microbeam at TIARA cyclotron

Yokota, Wataru; Sato, Takahiro; Oikawa, Masakazu*; Okumura, Susumu; Kurashima, Satoshi; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Yoshida, Kenichi; Kamiya, Tomihiro

JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 180, 2008/11

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2008-055.pdf

A fast single-ion hit system is being developed at the TIARA cyclotron using focused microbeam of several hundreds MeV with a spot of about 1 m in diameter. In order to achieve the goal hit rate of over 10/s, a magnetic scanner for the microbeam formation technique was replaced with a fast electrostatic scanner. The results of irradiation experiments show that the hit rate is higher than 10/s, the irradiation area is wider than 1000 m1000 m and the targeting accuracy is independent of hit rate. In addition, a test operation of quick change of ion species of microbeam was carried out applying the cocktail beam acceleration technique. Ion species was successfully changed in 30 minutes while the microbeam formation takes about 8 hours including cyclotron tuning. The result strongly indicates that we will be able to provide a different microbeam for plural ion species in an irradiation experiment by turns.

Intracellular changes of metal elements by fucoidan extracted from brown seaweed;

Nagamine, Takeaki*; Takada, Hisashi*; Kusakabe, Takahiko*; Nakazato, Kyomi*; Sakai, Takuro; Oikawa, Masakazu*; Kamiya, Tomihiro; Arakawa, Kazuo; Iha, Masahiko*

Biological Trace Element Research, 124(1), p.60 - 69, 2008/07

https://doi.org/10.1007/s12011-008-8123-x

This study was undertaken to elucidate the intracellular changes of metal elements after the administration of fucoidan extracted from . TRL1215 cells (normal rat liver cell line) were treated with 0, 0.1, or 1.0 mg/mL fucoidan. The cellular distribution of elements was analyzed using in-air micro-PIXE induced X-ray emission. In fucoidan-treated cells, the focal accumulation of Br (BrdU) was correlated spatially with phosphorous-rich region, suggesting that Br was localized within the nucleus. Al distribution provided a spatial association with Br map. These data suggest that fucoidan binding Al us postulated to be transferred into the nucleus.

Characterization of homoionic Fe-type montmorillonite; Potential chemical species of iron contaminant

Kozai, Naofumi; Inada, Koichi*; Adachi, Yoshifusa*; Kawamura, Sachi*; Kashimoto, Yusuke*; Kozaki, Tamotsu*; Sato, Seichi*; Onuki, Toshihiko; Sakai, Takuro; Sato, Takahiro; et al.

Journal of Solid State Chemistry, 180(8), p.2279 - 2289, 2007/08

https://doi.org/10.1016/j.jssc.2007.06.002

Fe-montmorillonite with Fe ions occupying cation exchange sites is an ideal transformation product in bentonite buffer material. We previously prepared a Fe-montmorillonite sample using a FeCl solution under an inert gas condition. This study attempted to determine the potential contaminant iron chemical species in the sample. It was found that a small amount of Cl ions remained dispersed throughout the sample. The Cl ion retention may be due to the adsorption of FeCl in the initial FeCl solution and the subsequent containment of the Cl ions that are dissociated from the FeCl during excess salt removal treatment. The latter may be explained by the slow release of the remaining Cl ions from the collapsed interlayer of the montmorillonite or the transformation of a minor fraction of the remaining FeCl to iron (III) hydroxide chloride complexes having low solubility.

Improvement in beam quality of the JAEA AVF cyclotron for focusing heavy-ion beams with energies of hundreds of MeV

Kurashima, Satoshi; Miyawaki, Nobumasa; Okumura, Susumu; Oikawa, Masakazu*; Yoshida, Kenichi; Kamiya, Tomihiro; Fukuda, Mitsuhiro*; Sato, Takahiro; Nara, Takayuki; Agematsu, Takashi; et al.

Nuclear Instruments and Methods in Physics Research B, 260(1), p.65 - 70, 2007/07

https://doi.org/10.1016/j.nimb.2007.01.278

no abstracts in English