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Journal Articles

Microstructural features and ductile-brittle transition behavior in hot-rolled lean duplex stainless steels

Takahashi, Osamu*; Shibui, Yohei*; Xu, P. G.; Harjo, S.; Suzuki, Tetsuya*; Tomota, Yo*

Quantum Beam Science (Internet), 4(1), p.16_1 - 16_15, 2020/03

Journal Articles

Hadronic Paschen-Back effect in charmonium

Iwasaki, Sachio; Oka, Makoto; Suzuki, Kei*; Yoshida, Tetsuya*

AIP Conference Proceedings 2130, p.050001_1 - 050001_8, 2019/07

We find a novel phenomenon induced by the interplay between a strong magnetic field and finite orbital angular momenta in hadronic systems, which is analogous to the Paschen-Back effect observed in the field of atomic physics. This effect allows the wave functions to drastically deform. We discuss anisotropic decay from the deformation as a possibility to measure the strength of the magnetic field in heavy-ion collision at LHC, RHIC and SPS, which has not experimentally been measured. As an example we investigate charmonia with finite orbital angular momentum in a strong magnetic field. We calculate the mass spectra and mixing rate. To obtain anisotropic wave functions, we apply the cylindrical Gaussian expansion method, where the Gaussian bases to expand the wave functions have different widths along transverse and longitudinal directions in the cylindrical coordinate.

Journal Articles

Hadronic Paschen-Back effect in P-wave charmonia under strong magnetic fields

Iwasaki, Sachio; Oka, Makoto; Suzuki, Kei*; Yoshida, Tetsuya*

International Journal of Modern Physics; Conference Series (Internet), 49, p.1960002_1 - 1960002_6, 2019/07

The hadronic Paschen-Back effects in P-wave charmonia are analyzed using the constituent quark models in strong magnetic field.

Journal Articles

Optimization of an isothermal gas-chromatographic setup for the chemical exploration of dubnium (Db, Z = 105) oxychlorides

Chiera, N. M.; Sato, Tetsuya; Tomitsuka, Tomohiro; Asai, Masato; Ito, Yuta; Shirai, Kaori*; Suzuki, Hayato; Tokoi, Katsuyuki; Toyoshima, Atsushi; Tsukada, Kazuaki; et al.

Journal of Radioanalytical and Nuclear Chemistry, 320(3), p.633 - 642, 2019/06

 Times Cited Count:0 Percentile:100(Chemistry, Analytical)

An isothermal gas-chromatographic (IGC) device has been developed and tested for on-line gas phase studies of volatile oxychlorides of short-lived group-5 transition metals. Radioisotopes of niobium and tantalum, produced in nuclear fusion evaporation reactions, are directly flushed into the IGC setup by an inert gas-jet. Oxychloride compounds are formed by the addition of SOCl$$_2$$ and O$$_2$$. Parameters influencing the formation and transport of NbOCl$$_3$$ and TaOCl$$_3$$ are investigated. For nuclides with half-lives ($$t_{1/2}$$) of about 30 s, an overall efficiency of 7% is obtained, rendering the IGC setup suitable for the chemical exploration of $$^{262}$$Db($$t_{1/2}$$ = 34s).

Journal Articles

Hadronic Paschen-Back effect

Iwasaki, Sachio; Oka, Makoto; Suzuki, Kei*; Yoshida, Tetsuya*

Physics Letters B, 790, p.71 - 76, 2019/03

 Times Cited Count:3 Percentile:32.71(Astronomy & Astrophysics)

We find a novel phenomenon induced by the interplay between a strong magnetic field and finite orbital angular momenta in hadronic systems, which is analogous to the Paschen-Back effect observed in the field of atomic physics. This effect allows the wave functions to drastically deform. We discuss anisotropic decay from the deformation as a possibility to measure the strength of the magnetic field in heavy-ion collision at LHC, RHIC and SPS, which has not experimentally been measured. As an example we investigate charmonia with finite orbital angular momentum in a strong magnetic field. We calculate the mass spectra and mixing rate. To obtain anisotropic wave functions, we apply the cylindrical Gaussian expansion method, where the Gaussian bases to expand the wave functions have different widths along transverse and longitudinal directions in the cylindrical coordinate.

Journal Articles

Formation and thermochemical properties of oxychlorides of niobium (Nb) and tantalum (Ta); Towards the gas-phase investigation of dubnium (Db) oxychloride

Chiera, N. M.; Sato, Tetsuya; Tomitsuka, Tomohiro; Asai, Masato; Suzuki, Hayato*; Tokoi, Katsuyuki; Toyoshima, Atsushi; Tsukada, Kazuaki; Nagame, Yuichiro

Inorganica Chimica Acta, 486, p.361 - 366, 2019/02

 Times Cited Count:1 Percentile:66.91(Chemistry, Inorganic & Nuclear)

The formation of NbOCl$$_3$$ and TaOCl$$_3$$ and their adsorption behavior on quartz surfaces was explored by applying an isothermal gas-chromatographic method. Trace amounts of short-lived Nb and Ta isotopes were used. Adsorption enthalpy values ($$Delta H_{rm ads}$$) at zero surface coverage of -$$Delta H_{rm ads}$$(NbOCl$$_3$$) = 102 $$pm$$ 4 kJ/mol and -$$Delta H_{rm ads}$$(TaOCl$$_3$$) = 128 $$pm$$ 5 kJ/mol were determined by analyzing the chromatographic behavior of the Nb andTa complexes with a Monte-Carlo simulation method based on an adsorption-desorption kinetic model.By applying an empirical correlation, the experimental $$Delta H_{rm ads}$$ values were successively related to the macroscopic standard sublimation enthalpy, $$Delta H^circ _{rm subl}$$, as a measure of the volatility of each substance. The inferred sublimation enthalpies are in agreement with tabulated thermochemical values. Thus, the linear empirical correlation between $$Delta H_{rm ads}$$ and $$Delta H^circ _{rm subl}$$ for metal-oxychlorides was updated with the inclusion of the present data. According to the predicted $$Delta H^circ _{rm subl}$$(DbOCl$$_3$$), a $$Delta H_{rm ads}$$(DbOCl$$_3$$) value of 135 $$pm$$ 2 kJ/mol was extrapolated. The future accomplishment of comparative studies with DbOCl$$_3$$ under the same experimental conditions will provide valuable information on the volatility trend in Group-5 elements, together with an indication on the magnitude of relativistic effects on the electronic structure of dubnium.

Journal Articles

Deformation analysis of reinforced concrete using neutron imaging technique

Koyama, Taku*; Ueno, Kazuki*; Sekine, Mariko*; Matsumoto, Yoshihiro*; Kai, Tetsuya; Shinohara, Takenao; Iikura, Hiroshi; Suzuki, Hiroshi; Kanematsu, Manabu*

Materials Research Proceedings, Vol.4, p.155 - 160, 2018/05

 Times Cited Count:0 Percentile:100

Journal Articles

Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex, 2; Neutron scattering instruments

Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.

Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12

The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.

Journal Articles

The Role of nitric oxide in radiation-induced bystander cell-killing effect

Yokota, Yuichiro; Funayama, Tomoo; Ikeda, Hiroko; Sakashita, Tetsuya; Suzuki, Michiyo; Kobayashi, Yasuhiko

JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 67, 2016/02

The role of nitric oxide (NO) in bystander effect was investigated. Human fibroblasts were irradiated with $$gamma$$-rays (LET: 0.2 keV/$$mu$$m) or carbon-ion beam (108 keV/$$mu$$m), and then, co-cultured with the non-irradiated cells. After 24 h culture, the survival rates of non-irradiated cells and the concentrations of nitrate, an oxide of NO, in the medium were measured. The survival rates of non-irradiated cells decreased in dose-dependent and radiation quality-independent manners. Negative relationships between survival rates and nitrite concentrations existed, indicating the amounts of produced NO are an important determinant of bystander effects. Next, a reagent producing two molecules of NO in a half-life of 100 min was added in the culture medium. After incubation of 24 h the survival rates of treated cells did not decrease, suggesting NO produced intracellularly has an important role to lead the bystander effect but is not the signal molecule for intercellular communication.

Journal Articles

Ion-track grafting of vinylbenzyl chloride into poly(ethylene-$$co$$-tetrafluoroethylene) films using different media

Nuryanthi, N.*; Yamaki, Tetsuya; Kitamura, Akane; Koshikawa, Hiroshi; Yoshimura, Kimio; Sawada, Shinichi; Hasegawa, Shin; Asano, Masaharu; Maekawa, Yasunari; Suzuki, Akihiro*; et al.

Transactions of the Materials Research Society of Japan, 40(4), p.359 - 362, 2015/12

The ion-track grafting of a vinylbenzyl chloride (VBC) into a poly(ethylene-co-tetrafluoroethylene) (ETFE) film is necessary for preparing nanostructured hydroxide-ion-conductive electrolyte membranes. A key for success here is to obtain as high graft levels as possible (for higher conductivity) in a smaller number of tracks (for improving the other membrane properties). To this end, therefore, the effect of the medium for the VBC grafting was investigated as part of our continuing effort to optimize the experimental conditions. A 25 $$mu$$m-thick ETFE film was irradiated in a vacuum chamber with 560 MeV $$^{129}$$Xe at different fluences, and then the grafting was performed by immersing the irradiated films in a 20vol% VBC monomer at 60$$^{circ}$$C. A medium was a mixture of water (H$$_{2}$$O) and isopropyl alcohol (iPrOH) at different volume ratios. The degree of grafting increased as the H$$_{2}$$O content became higher, and reached a maximum in pure H$$_{2}$$O. These results can be explained by considering the well-known Trommsdorff effect, in which poor solubility of the grafted polymer in polar media leads to an increased polymerization rate probably due to a lower termination rate.

Journal Articles

Temporal behavior of unresolved transition array emission in water window soft X-ray spectral region from multiply charged ions

Dinh, T.-H.*; Suzuki, Yuhei*; Arai, Goki*; Li, B.*; Dunne, P.*; O'Sullivan, G.*; Fujioka, Shinsuke*; Hasegawa, Noboru; Kawachi, Tetsuya; Nishikino, Masaharu; et al.

Applied Physics Letters, 107(12), p.121101_1 - 121101_5, 2015/09

 Times Cited Count:4 Percentile:73.21(Physics, Applied)

Journal Articles

Progress in bulk texture measurement using neutron diffraction

Xu, P. G.; Harjo, S.; Ito, Takayoshi*; Morii, Yukio*; Gong, W.; Suzuki, Hiroshi; Akita, Koichi; Suzuki, Tetsuya*; Tomota, Yo; Lutterotti, L.*

JPS Conference Proceedings (Internet), 8, p.031022_1 - 031022_6, 2015/09

Journal Articles

Enhanced lattice defect formation associated with hydrogen and hydrogen embrittlement under elastic stress of a tempered martensitic steel

Doshida, Tomoki*; Suzuki, Hiroshi*; Takai, Kenichi*; Hirade, Tetsuya; Oshima, Nagayasu*

NanotechJapan Bulletin (Internet), 8(3), 5 Pages, 2015/07

Studying the creation and time evolution of defects is an important issue for interpreting the hydrogen embrittlement mechanism of steels. We have been studied the relationship between hydrogen embrittlement of high strength steel and lattice defects associated with hydrogen by thermal desorption analysis (TDA) and positron probe microanalyzer (PPMA).

Journal Articles

Responses of the salt chemotaxis learning in ${it C. elegans}$ mutants to microbeam irradiation

Sakashita, Tetsuya; Suzuki, Michiyo; Hattori, Yuya; Ikeda, Hiroko; Muto, Yasuko*; Yokota, Yuichiro; Funayama, Tomoo; Hamada, Nobuyuki*; Shirai, Kana*; Kobayashi, Yasuhiko

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 74, 2015/03

An increasing body of data indicates that ionizing radiation affects the nervous system and alters its function. Recently, we reported that chemotaxis of ${it C. elegans}$ during the salt chemotaxis learning (SCL), that is conditioned taste aversion to NaCl, was modulated by carbon ion irradiation, i.e. accelerated decrease in chemotaxis to NaCl during the SCL. However, we had no direct evidence for the interaction of ionizing radiation with the central neuronal tissue (nerve ring) in ${it C. elegans}$. Microbeam irradiation is useful to analyze direct radiation effects at a cellular or tissue level. Thus, we applied the microbeam irradiation of the ${it C. elegans}$ nerve ring and examined the effect on the SCL.

Journal Articles

Effects of carbon-ion microbeam irradiation on locomotion and pharyngeal pumping motion in $textit{C. elegans}$

Suzuki, Michiyo; Hattori, Yuya; Sakashita, Tetsuya; Funayama, Tomoo; Yokota, Yuichiro; Ikeda, Hiroko; Kobayashi, Yasuhiko

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 88, 2015/03

Journal Articles

Bystander effect mediated by nitric oxide depends on irradiation dose but not on radiation quality

Yokota, Yuichiro; Funayama, Tomoo; Ikeda, Hiroko; Sakashita, Tetsuya; Suzuki, Michiyo; Kobayashi, Yasuhiko

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 75, 2015/03

We investigated the bystander effect induced by $$gamma$$-rays or carbon ions and analyzed the role of nitric oxide (NO) in the effect. Normal human fibroblasts were used. Cells inoculated on a porous membrane were irradiated with varying doses of $$gamma$$-rays or carbon ions. Irradiated cells were then non-contact co-cultured with non-irradiated cells for 24 h. After co-culture, the survival rates of non-irradiated bystander cells co-cultured with irradiated cells decreased with increasing dose and bottomed out at 0.5 Gy or higher doses. This indicates that the bystander effect is dependent on irradiation dose but independent of radiation quality. Next, a specific NO scavenger c-PTIO was added to the culture medium during irradiation and co-culture. This treatment prevented the reduction in survival rates of bystander cells, clearly indicating that NO has an important role in the bystander effect.

Journal Articles

Target irradiation of individual cells using focusing heavy-ion microbeam of JAEA-Takasaki, 5; Irradiation of individual cells with scanned heavy-ion microbeam

Funayama, Tomoo; Yokota, Yuichiro; Suzuki, Michiyo; Sakashita, Tetsuya; Kobayashi, Yasuhiko

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 73, 2015/03

Using a collimating heavy-ion microbeam system, we have explored various effects of heavy-ion hit on biological materials. However, there are limitations of the collimating system in the size of the microbeam spot and in the irradiation speed that cannot be overcome in principle. Thus, we started the development of a focusing microbeam system for target-irradiating individual cells more precisely. In this year, we established the protocol for irradiating "actual" cell sample with scanned beam. In the experiment, the HeLa cells were inoculated on a CR-39 film, then place on the sample stage. The microscopic image of cells was analyzed, and the cells were irradiated with scanned neon microbeam. After irradiation, we found the correspondence of the distribution pattern of the ion hit positions and the $$gamma$$-H2AX foci on cell nuclei, indicating rapid and accurate irradiation of individual cells with the focusing heavy-ion microbeam.

Journal Articles

Mechanisms for the induction of radioadaptive response by radiation-induced bystander response

Matsumoto, Hideki*; Tomita, Masanori*; Otsuka, Kensuke*; Hatashita, Masanori*; Maeda, Munetoshi*; Funayama, Tomoo; Yokota, Yuichiro; Suzuki, Michiyo; Sakashita, Tetsuya; Ikeda, Hiroko; et al.

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 76, 2015/03

The objective of this project is to elucidate molecular mechanisms for the induction of radioadaptive response through radiation-induced bystander responses induced by irradiation with heavy ion microbeams in JAEA. We found that the adaptive response was induced by Ar (520 MeV $$^{40}$$Ar$$^{14+}$$) microbeam-irradiation of a limited number of cells, followed by the broad beam-irradiation and that the adaptive response was almost completely suppressed by the addition of carboxy-PTIO, as a nitric oxide (NO) scavenger. In addition, we found several genes induced specifically and preferentially when radioadaptive response could be induced. We confirmed that ${it iNOS}$ expression was specifically induced only when radioadaptive response could be induced. Our findings strongly suggested that radioadaptive response can be induced by NO-mediated bystander responses evoked by irradiation with heavy ion microbeams.

Journal Articles

Analysis of bystander response in 3D cultured tissue induced by heavy-ion microbeam irradiation

Tomita, Masanori*; Matsumoto, Hideki*; Otsuka, Kensuke*; Funayama, Tomoo; Yokota, Yuichiro; Suzuki, Michiyo; Sakashita, Tetsuya; Kobayashi, Yasuhiko

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 77, 2015/03

Radiation-induced bystander responses are defined as responses in cells that have not been directly targeted by radiation but are in the neighborhood of cells that have been directly exposed. In this study, we aim to clarify a role of bystander response to sustain the homeostasis of damaged tissue using heavy-ion microbeams. We established the heavy-ion microbeam irradiation method to a 3D cultured human epidermis. Using this method, a viable cell rate of the 3D cultured human epidermis irradiated with 260 MeV $$^{20}$$Ne-ion microbeams or broadbeams was analyzed by the MTT method.

Journal Articles

Maintenance experiences at analytical laboratory at the Tokai Reprocessing Plant

Suzuki, Hisanori; Nagayama, Tetsuya; Horigome, Kazushi; Ishibashi, Atsushi; Kitao, Takahiko; Surugaya, Naoki

Nippon Hozen Gakkai Dai-11-Kai Gakujutsu Koenkai Yoshishu, p.214 - 219, 2014/07

The Tokai Reprocessing Plant (TRP) is developing the technology to recover uranium and plutonium from spent nuclear fuel. There is an analytical laboratory which was built in 1978, as one of the most important facilities for process and material control analyses at the TRP. Samples taken from each process are analyzed by various analytical methods using hot cells, glove boxes and hume-hoods. A large number of maintenance work have been so far done and different types of experience have been accumulated. This paper describes our achievements in the maintenance activities at the analytical laboratory at the TRP.

390 (Records 1-20 displayed on this page)