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Application of multiple $$gamma$$-ray detection to long-lived radioactive nuclide determination in environmental samples

大島 真澄*; 後藤 淳*; 原賀 智子; 金 政浩*; 池部 友理恵*; 瀬戸 博文*; 伴場 滋*; 篠原 宏文*; 森本 隆夫*; 磯貝 啓介*

Journal of Nuclear Science and Technology, 57(6), p.663 - 670, 2020/06

 被引用回数:0 パーセンタイル:0.01(Nuclear Science & Technology)

多重$$gamma$$線検出法は、$$gamma$$線スペクトロメトリーにおけるシグナルノイズ比の改善に有効な手法である。本研究では、福島第一原子力発電所から放出された放射性核種として、$$^{137}$$Csを含む試料を想定し、長半減期の$$gamma$$線放出核種である$$^{60}$$Co, $$^{94}$$Nb, $$^{134}$$Cs, $$^{152}$$Euおよび$$^{154}$$Euの5核種を対象として、多重$$gamma$$線検出法の適用性を検討した。その結果、通常の$$gamma$$線スペクトロメトリーと比較して、シグナルノイズ比は9.8から283倍の改善効果が得られ、検出限界値は2.7から8.5倍の改善効果が得られた。本法の適用により、検出限界値を大幅に改善でき、放射性廃棄物の処分において重要となる長半減期の$$gamma$$線放出核種に対する多重$$gamma$$線検出法の適用性を確認できた。


Sensitivity of charged particle activation analysis for long-lived radioactive nuclide determination

大島 真澄*; 山口 友理恵*; 浅井 雅人; 塚田 和明; 後藤 淳*; 伴場 滋*; Bi, C.*; 森本 隆夫*

Journal of Nuclear Science and Technology, 56(9-10), p.866 - 872, 2019/09

 被引用回数:1 パーセンタイル:23.13(Nuclear Science & Technology)

長寿命放射性核種35核種の定量のため、8MeV陽子ビームを用いた荷電粒子放射化分析法の分析感度について調査した。それらの核種に対する核反応断面積はALICE-91コードによって見積もり、核異性体生成比は近傍同位体の値からそれらのスピン・パリティの値を考慮して見積もった。その結果、提案する荷電粒子放射化分析法は$$^{135}$$Cs, $$^{244}$$Pu, $$^{129}$$I, $$^{126}$$Sn, $$^{93}$$Mo, $$^{107}$$Pd, $$^{236}$$U, $$^{248}$$Cm, $$^{237}$$Npなどのいくつかの難測定長寿命核種に対して高い感度を示すことが判った。


New application of NV centers in CVD diamonds as a fluorescent nuclear track detector

小野田 忍; 春山 盛善; 寺地 徳之*; 磯谷 順一*; 加田 渉*; 花泉 修*; 大島 武

Physica Status Solidi (A), 212(11), p.2641 - 2644, 2015/11

 被引用回数:6 パーセンタイル:33.5(Materials Science, Multidisciplinary)

Nitrogen-vacancy (NV) center in diamond is a luminescent point defect with applications of quantum computation and atomic scale sensors. One of the most important features of NV center is high emission rate. This enables single NV centers to be detected using a confocal laser scanning microscope. In this study, we propose a new application of NV centers as a single ion track detector. We perform 490 MeV Os ion irradiation to diamond grown by chemical vapor deposition (CVD) technique. After high temperature annealing at 1000 $$^{circ}$$C, the ion track is able to be visualized by using confocal laser scanning microscope. In short, we have successfully detected ion track in diamonds.


NV centers in diamond used for detection of single ion track

春山 盛善; 小野田 忍; 加田 渉*; 寺地 徳之*; 磯谷 順一*; 大島 武; 花泉 修*

Proceedings of 11th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-11) (Internet), p.184 - 187, 2015/11

We propose that diamond can be utilized as a new Fluorescent Nuclear Track Detector (FNTD) material. For this aim, we focus on Nitrogen Vacancy (NV) centers in diamond. One of the most important features of a NV center is a high emission rate, which enable us to observe single NV center. After high energy ion irradiation and subsequent annealing, we successfully observe Os ion tracks in various diamonds containing dense nitrogen impurity. However, Os ion track cannot be observed from diamond without nitrogen impurity. We found that the optimization of nitrogen impurity is a key issue for developing high sensitive FNTD based on diamond.


Hydrophobic platinum honeycomb catalyst to be used for tritium oxidation reactors

岩井 保則; 久保 仁志*; 大嶋 優輔*; 野口 宏史*; 枝尾 祐希; 谷内 淳一*

Fusion Science and Technology, 68(3), p.596 - 600, 2015/10

 被引用回数:0 パーセンタイル:0.01(Nuclear Science & Technology)



Superdeformation in $$^{35}$$S

郷 慎太郎*; 井手口 栄治*; 横山 輪*; 小林 幹*; 木佐森 慶一*; 高木 基伸*; 宮 裕之*; 大田 晋輔*; 道正 新一郎*; 下浦 享*; et al.

JPS Conference Proceedings (Internet), 6, p.030005_1 - 030005_4, 2015/06

The high-spin states in $$^{35}$$S were investigated at Tandem-ALTO facility in Institut de Physique Nucl$'e$aire d'Orsay The $$^{26}$$Mg($$^{18}$$O, 2$$alpha$$1n)$$^{35}$$S fusion evaporation reaction was used to populate high-spin states in $$^{35}$$S. The germanium $$gamma$$-ray detector array ORGAM was employed to measure $$gamma$$ rays from high-spin states and charged particles evaporated from the compound nuclei were detected by a segmented silicon detector, Si-Ball. A level scheme for $$^{35}$$S was deduced based on the gamma-gamma-coincidence analysis and $$gamma$$-ray angular correlation analysis. The half-life of the transition in the superdeformed band was estimated by measuring the residual Doppler shift. The deduced half-life shows the large collectivity of the band.


Hydrophobic Pt catalyst for combustion of hydrogen isotopes at low temperatures

岩井 保則; 久保 仁志*; 佐藤 克美; 大嶋 優輔*; 野口 宏史*; 谷内 淳一*

Proceedings of 7th Tokyo Conference on Advanced Catalytic Science and Technology (TOCAT-7) (USB Flash Drive), 2 Pages, 2014/06



Cross section measurements of the radioactive $$^{107}$$Pd and stable $$^{105,108}$$Pd nuclei at J-PARC/MLF/ANNRI

中村 詔司; 木村 敦; 北谷 文人; 太田 雅之; 古高 和禎; 後神 進史*; 原 かおる; 原田 秀郎; 廣瀬 健太郎; 金 政浩*; et al.

Nuclear Data Sheets, 119, p.143 - 146, 2014/05

 被引用回数:8 パーセンタイル:56.03(Physics, Nuclear)



Capture cross-section measurement of $$^{241}$$Am(n,$$gamma$$) at J-PARC/MLF/ANNRI

原田 秀郎; 太田 雅之; 木村 敦; 古高 和禎; 廣瀬 健太郎; 原 かおる; 金 政浩*; 北谷 文人; 小泉 光生; 中村 詔司; et al.

Nuclear Data Sheets, 119, p.61 - 64, 2014/05

 被引用回数:18 パーセンタイル:78.97(Physics, Nuclear)

Accurate determination of the neutron capture cross sections of radioactive nuclei is required in the fields of nuclear waste transmutation study and also nuclear astrophysics. The accurate neutron-nucleus reaction measurement instrument (ANNRI), which was installed in the materials and life science experimental facility (MLF) at the J-PARC, is expected to satisfy these demands. The capture cross section of $$^{241}$$Am was measured using a high efficiency Ge spectrometer installed in the ANNRI. By taking advantage of its high $$gamma$$-ray energy resolution, background components were precisely subtracted. The capture cross section of $$^{241}$$Am was deduced for a neutron energy region between 0.01 and 20 eV. The obtained cross section and the Westcott factor are compared with the preceding experiments and evaluated values.


Measurements of capture $$gamma$$ rays from the neutron resonances of $$^{74}$$Se and $$^{77}$$Se at the J-PARC/MLF/ANNRI

堀 順一*; 八島 浩*; 中村 詔司; 古高 和禎; 原 かおる; 原田 秀郎; 廣瀬 健太郎; 木村 敦; 北谷 文人; 小泉 光生; et al.

Nuclear Data Sheets, 119, p.128 - 131, 2014/05

 被引用回数:3 パーセンタイル:30.04(Physics, Nuclear)

本研究では、$$^{74}$$Seと$$^{77}$$Seの中性子共鳴からの捕獲$$gamma$$線を測定した。$$^{74}$$Seは、簡単な殻模型から2p$$_{1/2}$$軌道まで中性子が占有されている偶-偶核であるので、プライマリ$$gamma$$線遷移の始状態と終状態間の強い相関が予想される。$$^{74}$$Seは、安定Se同位体の中で唯一の奇数核であるので、同じ奇数核である$$^{79}$$Seの評価に資する情報を含んでいると期待される。J-PARC、物質・生命科学実験施設(MLF)の中性子核反応実験装置(ANNRI)に整備した4$$pi$$ Geスペクトロメータを用いて、飛行時間法により測定を行った。$$^{74}$$Seの27eV共鳴、及び$$^{77}$$Seの113eV, 212eV, 291eV, 342eV, 690eV及び864eV共鳴に対応する$$gamma$$線波高スペクトルを得た。これらのプライマリ遷移$$gamma$$線の相対強度を求め、報告されている実験データと比較を行った。$$^{74}$$Seの27eV共鳴について、293keV準位への強いプライマリ遷移が観測された。$$^{77}$$Seについては、共鳴ごとに全く異なる崩壊パターンを見いだした。


Cross section measurement of $$^{237}$$Np$$(n,gamma)$$ at J-PARC/MLF/ANNRI

廣瀬 健太郎; 古高 和禎; 原 かおる; 原田 秀郎; 堀 順一*; 井頭 政之*; 加美山 隆*; 片渕 竜也*; 木村 敦; 金 政浩*; et al.

Nuclear Data Sheets, 119, p.48 - 51, 2014/05

 被引用回数:1 パーセンタイル:11.75(Physics, Nuclear)

The cross section of the $$^{237}$$Np$$(n,gamma)$$ reaction has been measured in an energy range from 10 meV to 1 keV at the Japan Proton Accelerator Research Complex (J-PARC). The NaI(Tl) spectrometer installed in the accurate neutron-nucleus reaction measurement instrument (ANNRI) was used for the measurement. The relative cross section was obtained using the neutron spectrum measured by the $$^{10}$$B$$(n,alpha_1)$$ reaction. The absolute value of the cross section was deduced by normalizing the relative cross section to the evaluated value in JENDL-4.0 at the first resonance. In this presentation, the obtained results for the cross section, the Westcott factor and the resonance analysis are reported. This work was supported by JSPS KAKENHI Grant Number 22226016.


Hydrogen at zinc vacancy of ZnO; An EPR and ESEEM study

Son, N. T.*; 磯谷 順一*; Ivanov, I. G.*; 大島 武; Janz$'e$n, E.*

AIP Conference Proceedings 1583, p.341 - 344, 2014/02

Defect centers in zinc oxide (ZnO) were investigated using electron paramagnetic resonance (EPR) techniques. Un-doped ZnO samples were irradiated with 2MeV electrons with fluence ranges between 2 and 4$$times$$10$$^{18}$$ /cm$$^{2}$$ at room temperature. As a result of EPR measurements, the spectrum, labeled S1, with small-splitting doublet accompanied by weak satellites was observed. The obtained structure is shown to be the hyperfine structure because of the dipolar interaction between an unpaired electron spin and a nuclear spin of hydrogen (H). The presence of H atom in S1 was confirmed from the observation of the nuclear Zeeman frequency of H in electron spin echo envelope modulation experiments. Considering the observed spin-Hamiltonian parameters, S1 was identified to be the partly H-passivated Zn vacancy, V$$_{Zn}$$$$^{-}$$H$$^{+}$$, with the H$$^{+}$$ ion making a short O-H bond with only one nearest O neighbor of V$$_{Zn}$$ in the basal plane, being off the substitutional site, while the unpaired electron spin, by which the observed EPR signal increased, was localized on the p orbital of another O neighbor also in the basal plane.


Quantum error correction in a solid-state hybrid spin register

Waldherr, G.*; Wang, Y.*; Zaiser, S.*; Jamali, M.*; Schulte-Herbr$"u$ggen, T.*; 阿部 浩之; 大島 武; 磯谷 順一*; Du, J. F.*; Neumann, P.*; et al.

Nature, 506(7487), p.204 - 207, 2014/02

 被引用回数:310 パーセンタイル:99.59(Multidisciplinary Sciences)

量子ビットが担う"重ね合わせ"という量子情報は、外部との意図しない相互作用により容易に壊されるので、量子エラー訂正無しでは量子コンピューティングは実現困難である。ダイヤモンド中のカラーセンターの一つであるNVセンターの単一分子に相当する単一欠陥を用いて、電子スピン1個と核スピン3個からなるハイブリッド量子レジスタを作製($$^{12}$$C 99.8%濃縮した合成ダイヤモンド結晶に電子線照射と熱処理によりNVセンターを形成)し、室温動作の固体スピン量子キュービットでは世界で初めて量子エラー訂正のプロトコルの実行に成功した。この方法はスケーラブルなので、フォールト・トレラントな量子操作を多量子ビットへ拡張することが可能となり、固体量子情報デバイス実現への道を開くものである。


Energy resolution of pulsed neutron beam provided by the ANNRI beamline at the J-PARC/MLF

木野 幸一*; 古坂 道弘*; 平賀 富士夫*; 加美山 隆*; 鬼柳 善明*; 古高 和禎; 後神 進史*; 原 かおる; 原田 秀郎; 原田 正英; et al.

Nuclear Instruments and Methods in Physics Research A, 736, p.66 - 74, 2014/02

 被引用回数:22 パーセンタイル:90.45(Instruments & Instrumentation)

We studied the energy resolution of the pulsed neutron-beam of Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) at the Japan Proton Accelerator Research Complex/Materials and Life Science Experimental Facility (J-PARC/MLF). A simulation in the energy region from 0.7 meV to 1 MeV has been performed. Moreover, measurements have been done in the thermal and epithermal energies. The neutron energy resolution at ANNRI, which is determined by the time-of-flight technique, depends on the time structure of the neutron pulse. We obtained the neutron energy resolution as a function of the neutron energy by the simulation in the two operation modes of the neutron source: double and single bunch modes. In the double bunch mode, the resolution deteriorates above about 10 eV because the time structure of the neutron pulse splits into two peaks. The time structures at 13 energy points by measurements in the thermal energy region are in agreement with those of the simulation. In the epithermal energy region, the time structures at 17 energy points were obtained by measurements. The FWHM values of the time structures by the simulation and measurements are almost consistent. In the single bunch mode, the energy resolution is better than about 1% between 1 meV and 10 keV at the neutron source operation of 17.5 kW.


Cross section measurement of $$^{117}$$Sn$$(n,gamma)$$ using ANNRI-NaI(Tl) spectrometer at J-PARC

廣瀬 健太郎; 古高 和禎; 原 かおる; 原田 秀郎; 木村 敦; 北谷 文人; 小泉 光生; 中村 詔司; 大島 真澄; 藤 暢輔; et al.

JAEA-Conf 2013-002, p.173 - 178, 2013/10

The cross section for $$^{117}$$Sn$$(n,gamma)$$ reaction has been measured in the neutron energy from 1eV to 1keV using the ANNRI-NaI(Tl) spectrometer at J-PARC/MLF. The sample used in the present experiment was metal tin enriched in $$^{117}$$Sn by 87%. The impurities of $$^{116}$$Sn and $$^{118}$$Sn were 9.3% and 3%, respectively. In the data analysis, the background of the frame-overlap neutrons and the scattered neutrons were subtracted. Comparison with the evaluation of JENDL-4.0 and ENDF/B-VII.1 will be presented in the poster session.


Cross-section measurement of $$^{237}$$Np$$(n,gamma)$$ from 10 meV to 1 keV at Japan Proton Accelerator Research Complex

廣瀬 健太郎; 古高 和禎; 原 かおる; 原田 秀郎; 木村 敦; 金 政浩*; 北谷 文人; 小泉 光生; 中村 詔司; 大島 真澄; et al.

Journal of Nuclear Science and Technology, 50(2), p.188 - 200, 2013/02

 被引用回数:26 パーセンタイル:92.04(Nuclear Science & Technology)



Probing carbon edge exposure of iron phthalocyanine-based oxygen reduction catalysts by soft X-ray absorption spectroscopy

丹羽 秀治*; 斎藤 信*; 小林 正起*; 原田 慈久*; 尾嶋 正治*; 守屋 彰悟*; 松林 克征*; 難波江 裕太*; 黒木 重樹*; 池田 隆司; et al.

Journal of Power Sources, 223, p.30 - 35, 2013/02

 被引用回数:17 パーセンタイル:54.86(Chemistry, Physical)

固体高分子形燃料電池用の非白金で、安価で、高性能の炭素正極触媒をデザインするには、酸素還元反応の活性点を明らかにすることが重要である。しかしながら、このような複雑な系においては通常用いられる原子・電子構造プローブにより活性点を直接特定するのは困難である。本研究では、炭素1${it s}$X線吸収分光を用いて鉄フタロシアニンをもとにした触媒の炭素構造を観察し、$$pi^{ast}$$吸収端以下に炭素端の露出を意味する構造を見いだした。またその強度は酸素還元活性とよく相関することがわかった。これらの結果は、炭素1${it s}$X線吸収分光を用いることにより炭素正極触媒における酸素還元活性の評価が端の露出の観点から可能であることを示している。


Development of the RAQM2 aerosol chemical transport model and predictions of the Northeast Asian aerosol mass, size, chemistry, and mixing type

梶野 瑞王*; 猪俣 弥生*; 佐藤 啓市*; 植田 洋匡*; Han, Z.*; An, J.*; 堅田 元喜; 出牛 真*; 眞木 貴史*; 大島 長*; et al.

Atmospheric Chemistry and Physics, 12(24), p.11833 - 11856, 2012/12

 被引用回数:43 パーセンタイル:78.96(Environmental Sciences)



Lethal and mutagenic effects of ion beams and $$gamma$$-rays in ${it Aspergillus oryzae}$

豊島 快幸*; 高橋 明珠*; 田中 寿基*; 渡部 潤*; 茂木 喜信*; 山崎 達雄*; 濱田 涼子*; 岩下 和裕*; 佐藤 勝也; 鳴海 一成

Mutation Research; Fundamental and Molecular Mechanisms of Mutagenesis, 740(1-2), p.43 - 49, 2012/12

 被引用回数:12 パーセンタイル:41.43(Biotechnology & Applied Microbiology)

${it Aspergillus oryzae}$ is a fungus that is used widely in traditional Japanese fermentation industries. In this study, the lethal and mutagenic effects of different linear energy transfer (LET) radiation in freeze-dried conidia of ${it A. oryzae}$ were investigated. The lethal effect, which was evaluated by a 90% lethal dose, was dependent on the LET value of the ionizing radiation. The most lethal ionizing radiation among that tested was $$^{12}$$C$$^{5+}$$ ion beams with an LET of 121 keV/$$mu$$m. The $$^{12}$$C$$^{5+}$$ ion beams had a 3.6-times higher lethal effect than low-LET (0.2 keV/$$mu$$m) $$gamma$$-rays. The mutagenic effect was evaluated by the frequency of selenate resistant mutants. $$^{12}$$C$$^{6+}$$ ion beams with an LET of 86 keV/$$mu$$m were the most effective in inducing selenate resistance. The mutant frequency following exposure to $$^{12}$$C$$^{6+}$$ ion beams increased with an increase in dose and reached 3.47 $$times$$ 10$$^{-3}$$ at 700 Gy. In the dose range from 0 to 700 Gy, $$^{12}$$C$$^{5+}$$ ion beams were the second most effective in inducing selenate resistance, the mutant frequency of which reached a maximum peak (1.67 $$times$$ 10$$^{-3}$$) at 400 Gy. To elucidate the characteristics of mutation induced by ionizing radiation, mutations in the sulphate permease gene (${it sB}$) and ATP sulfurylase gene (${it sC}$) loci, the loss of function of which results in a selenate resistant phenotype, were compared between $$^{12}$$C$$^{5+}$$ ion beams and $$gamma$$-rays. We detected all types of transversions and transitions. For frameshifts, the frequency of a +1 frameshift was the highest in all cases. Although the incidence of deletions $$>$$ 2 bp was generally low, deletions $$>$$ 20 bp were characteristic for $$^{12}$$C$$^{5+}$$ ion beams. $$gamma$$-rays had a tendency to generate mutants carrying a multitude of mutations in the same locus. Both forms of radiation also induced genome-wide large-scale mutations including chromosome rearrangements and large deletions.


Development of ion photon emission microscopy at JAEA

小野田 忍; 阿部 浩之; 山本 卓; 大島 武; 磯谷 順一*; 寺地 徳之*; 渡邊 賢司*

Proceedings of 10th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-10) (Internet), p.93 - 96, 2012/12

We have developed two systems to acquire two-dimensional maps of Single Event Effects (SEEs) by using focused microbeams. While the microbeam has many advantages for SEE testing, the transport and optimization of the microbeam requires much time and effort, especially for high energy heavy ions. Therefore the mapping system with less effort is required, and we are developing the Ion Photon Emission Microscopy (IPEM). Since the spatial resolution is determined by the spot size and the intensity of luminescence, the scintillator is one of the most important parts of IPEM. We propose that the diamond containing Nitrogen Vacancy (NV) centers can be used as a scintillator. For both diamond and YAG:Ce proposed by Sandia National Laboratories, the minimum spot size is a few micrometers. IBIL intensity from diamond is four times higher than that from YAG:Ce. Therefore, we propose that the diamond containing NV centers is a rival candidate of YAG:Ce for IPEM.

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