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中島 健次; 川北 至信; 伊藤 晋一*; 阿部 淳*; 相澤 一也; 青木 裕之; 遠藤 仁*; 藤田 全基*; 舟越 賢一*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
J-PARC物質・生命科学実験施設の中性子実験装置についてのレビューである。物質・生命科学実験施設には23の中性子ビームポートがあり21台の装置が設置されている。それらは、J-PARCの高性能な中性子源と最新の技術を組み合わせた世界屈指の実験装置群である。このレビューでは、装置性能や典型的な成果等について概観する。
石井 賢司*; 遠山 貴巳*; 浅野 駿*; 佐藤 研太朗*; 藤田 全基*; 脇本 秀一; 筒井 健二*; 曽田 繁利*; 宮脇 淳*; 丹羽 秀治*; et al.
Physical Review B, 96(11), p.115148_1 - 115148_8, 2017/09
被引用回数:32 パーセンタイル:78.51(Materials Science, Multidisciplinary)We investigate electronic excitations in La(Br,Sr)CuO using resonant inelastic X-ray scattering (RIXS) at the oxygen edge. We observed momentum-dependent spectral weight below 1 eV, which is consistent with theoretical calculation of the dynamical charge structure factor on oxygen orbitals in a three-band Hubbard model. Our results confirm that the momentum-dependent charge excitations exist on the order of the transfer energy (), and the broad spectral line shape indicates damped and incoherent character of the charge excitations at the energy range in the doped Mott insulators.
廣瀬 健太郎; 西尾 勝久; 牧井 宏之; 西中 一朗*; 太田 周也*; 永山 達郎*; 田村 信行*; 後藤 真一*; Andreyev, A. N.; Vermeulen, M. J.; et al.
Nuclear Instruments and Methods in Physics Research A, 856, p.133 - 138, 2017/06
被引用回数:5 パーセンタイル:41.83(Instruments & Instrumentation)Fission and capture reactions were simultaneously measured in the neutron-induced reactions of Am at J-PARC. Data were taken with the TOF method in = 0.120 eV. The fission events were observed by detecting prompt fission neutrons using liquid organic scintillators. The capture reaction was measured by detecting rays from the compound nuclei using the same detectors, where the prompt fission neutrons and capture rays were separated by a pulse shape analysis. The cross sections were obtained by normalizing the relative yields at the first resonance to evaluations or other experimental data. The ratio of the fission to capture cross sections at each resonance is compared with those from an evaluated nuclear data library and other experimental data. Some differences were found between the present values and the library/literature values at several resonances.
味村 周平*; Bezerra, T. J. C.*; Chauveau, E.*; Enomoto, T.*; 古田 久敬*; 原田 正英; 長谷川 勝一; Hiraiwa, T.*; 五十嵐 洋一*; 岩井 瑛人*; et al.
Progress of Theoretical and Experimental Physics (Internet), 2015(6), p.063C01_1 - 063C01_19, 2015/06
被引用回数:6 パーセンタイル:44.19(Physics, Multidisciplinary)J-PARC E56実験は物質・生命科学実験施設においてステライルニュートリノを探索する実験である。実験の妥当性を検証するために、われわれはMLF 3Fにバックグランドイベント用検出器を設置し、測定を行った。この検出器は500Kgのプラスチックシンチレータから構成されている。陽子ビーム入射によって線と中性子が生成され、宇宙線起源の線なども検出された。これらの結果について報告する。
片渕 竜也*; 松橋 泰平*; 寺田 和司; 井頭 政之*; 水本 元治*; 廣瀬 健太郎; 木村 敦; 岩本 信之; 原 かおる*; 原田 秀郎; et al.
Physical Review C, 91(3), p.037603_1 - 037603_5, 2015/03
被引用回数:8 パーセンタイル:49.36(Physics, Nuclear)Time-of-flight spectra of the neutron capture events of Nd were measured using a spallation neutron source at the Japan Proton Accelerator Research Complex. The first six resonances of Nd reported in a previous work were not observed. The experimental results and cross-search of resonance energies in nuclear data libraries suggested that resonances of impurity nuclide Pr have been mistakenly assigned as Nd in the previous experiment. To investigate the impact of non-existence of the resonances to the s-process nucleosynthesis model, the Maxwellian averaged neutron capture cross sections with and without the misassigned resonances were compared.
原 かおる; 後神 進史*; 原田 秀郎; 廣瀬 健太郎; 木村 敦; 金 政浩*; 北谷 文人; 小泉 光生; 中村 詔司; 藤 暢輔; et al.
JAEA-Conf 2014-002, p.88 - 92, 2015/02
Recently, neutron shields of a large Ge detector array at the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) in the Japan Proton Accelerator Research Complex (J-PARC) were modified to suppress the background from boron rubber sheets to enriched LiF tiles. For the new experimental set-up, efficiencies and response functions of the cluster Ge detectors with the BGO anti-coincidence detectors were measured with -rays from standard sources and prompt -rays from the Si(n,) and Cl(n,) reactions. The simulation parameters were adjusted with the EGS5 code so as to reproduce the data set of efficiencies and response functions. Based on this information, a pulse height weighting function will be deduced in the energy range of 0.1-10 MeV.
Hwang, J.-G.*; Kim, E.-S.*; 宮島 司*; 本田 洋介*; 原田 健太郎*; 島田 美帆*; 高井 良太*; 久米 達哉*; 長橋 進也*; 帯名 崇*; et al.
Nuclear Instruments and Methods in Physics Research A, 753, p.97 - 104, 2014/07
被引用回数:7 パーセンタイル:46.64(Instruments & Instrumentation)For a future synchrotron light source based on a linac, e.g. an X-ray free electron laser and an energy recovery linac (ERL), an injector is a key component to generate a high brightness electron beam. For the acceleration and transportation of the electron beam in the injector, the adjustment of beam orbit inside the cavity is important to avoid the deterioration of the beam quality due to the transverse electric field of it, which causes the transverse emittance growth. To adjust the beam orbit, an investigation of the electromagnetic center of the cavity is required in the beam operation. This paper shows a new method for measuring the electromagnetic center of the cavity, and describes an analytical model of emittance growth due to a combination of transverse electric field and orbit offset. The validation of the method was confirmed by the emittance measurement in the compact ERL (cERL) injector at KEK.
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:9.89(Physics, Nuclear)The cross section of the Np 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 B 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.
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:10 パーセンタイル:56.12(Physics, Nuclear)長寿命放射性核種Pd、及び不純物として含まれている安定核種Pdの中性子捕獲断面積を測定した。J-PARCの物質・生命科学実験施設(MLF)のBL04に整備された中性子核反応実験装置(ANNRI)を用いて、飛行時間法により熱領域から300eVの中性子エネルギーに対して、中性子捕獲断面積を測定した。報告されていた幾つかの共鳴が、Pdに起因しないことなど、共鳴に関する新たな知見が得られた。
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:4 パーセンタイル:32.02(Physics, Nuclear)本研究では、SeとSeの中性子共鳴からの捕獲線を測定した。Seは、簡単な殻模型から2p軌道まで中性子が占有されている偶-偶核であるので、プライマリ線遷移の始状態と終状態間の強い相関が予想される。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 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。Seの27eV共鳴、及びSeの113eV, 212eV, 291eV, 342eV, 690eV及び864eV共鳴に対応する線波高スペクトルを得た。これらのプライマリ遷移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。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。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。
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:19 パーセンタイル:75.15(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 Am was measured using a high efficiency Ge spectrometer installed in the ANNRI. By taking advantage of its high -ray energy resolution, background components were precisely subtracted. The capture cross section of 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.
木村 敦; 廣瀬 健太郎; 中村 詔司; 原田 秀郎; 原 かおる; 堀 順一*; 井頭 政之*; 加美山 隆*; 片渕 竜也*; 木野 幸一*; et al.
Nuclear Data Sheets, 119, p.150 - 153, 2014/05
被引用回数:5 パーセンタイル:37.18(Physics, Nuclear)The neutron-capture cross sections of Sn and Sn were measured by the time-of-flight method in the energy range from 10 meV to 2 keV with an array of germanium detectors in ANNRI at J-PARC. The preliminary results of the neutron-capture cross sections for Sn and Sn were obtained by normalizing the relative cross sections to the thermal cross section measured by Krane and to the evaluated value of JENDL-4.0 at the 47.05-eV resonance, respectively. Twelve new resonances for Sn were observed, whereas the 21.02-, 40.38- and 166-eV resonances for Sn and the 289-eV resonance for Sn which are listed on JENDL-4.0 and/or ENDF/B VII.1 were not observed. The prompt -ray distributions gated at the Sn and Sn resonances were obtained. Twenty-three new prompt -ray emissions were observed in the Sn (n,) reactions.
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:32 パーセンタイル:91.55(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.
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 Sn 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 Sn by 87%. The impurities of Sn and 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.
原 かおる; 後神 進史*; 原田 秀郎; 廣瀬 健太郎; 木村 敦; 金 政浩*; 北谷 文人; 小泉 光生; 中村 詔司; 藤 暢輔
JAEA-Conf 2013-002, p.161 - 166, 2013/10
For a pulse-height weighting technique, responses of two cluster Ge detectors with BGO anti-coincidence detectors have been measured at the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) in the Japan Proton Accelerator Research Complex (J-PARC). Co and Cs standard sources were used for low-energy region (E 2 MeV). Prompt -rays emitted from the Cl(n,)Cl reactions were used for high-energy region (E 8 MeV). The measured spectra, peak efficiencies, and peak-to-total ratio were compared to simulations which were calculated by using the EGS5 code in the energy range 0.5-10 MeV. The response function will be applied to a data analysis in neutron capture reaction measurements at ANNRI.
金 政浩*; 永井 泰樹; 岩本 信之; 湊 太志; 岩本 修; 初川 雄一; 瀬川 麻里子; 原田 秀郎; 今野 力; 落合 謙太郎; et al.
Journal of the Physical Society of Japan, 82(3), p.034201_1 - 034201_8, 2013/03
被引用回数:33 パーセンタイル:80.42(Physics, Multidisciplinary)分子イメージングと核医学治療に期待されている放射性同位体CuとCuの生成断面積を14MeVの加速器中性子を用い測定した。この結果とZn同位体の断面積評価値を用いて、40MeVで5mAの重陽子ビームによるC(d,n)反応からの速中性子を用いて生成されるCuとCuの量を計算した。Cuの生成量は、12時間照射で175gのZnについて1.8テラベクレルであり、Cuの生成量は2日間の照射で、Zn(n,p)Cu反応では184g Znに対して249ギガベクレルであり、Zn(n,x)Cuでは186g Znに対して287ギガベクレルである。以上より、Cuの生成には、極微量不純物放射性同位体しか生成しないZn(n,x)Cu反応を新しく提唱した。また、Cuの生成には、Zn(n,p)Cu反応が期待できる反応であることを示した。
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:29 パーセンタイル:89.47(Nuclear Science & Technology)J-PARC/ANNRIに設置したNaI検出器を用いて、Np反応断面積を中性子エネルギー10meVから1keVにおいて測定した。断面積のエネルギー依存性はB反応をリファレンスとして求め、絶対値はJENDL-4.0評価済データを用い、第1共鳴で規格化することで得た。得られた熱中性子捕獲断面積は(176.74.7)bであった。また、=25.3meVに対するマクスウェル平均断面積は(174.65.1)bであった。マクスウェル平均断面積を求める際、10meV以下での断面積はJENDL-4.0を参照した。これらの結果から、Westcottの-factorとして0.9880.010が得られた。これは最新のLANLの測定値0.9440.035に比べ、約5%大きな結果である。
中村 詔司; 太田 雅之; 大島 真澄; 北谷 文人; 木村 敦; 金 政浩; 小泉 光生; 後神 進史*; 藤 暢輔; 原 かおる; et al.
JAEA-Conf 2012-001, p.147 - 152, 2012/07
The neutron capture cross section of Pd in the thermal-neutron energy region has been measured relative to the B(n,) reaction cross section by the neutron time-of-flight (TOF) method. The relative cross section was normalized to the average value calculated by the SAMMY code with JENDL-4.0 at the three energy points: 6.8 eV of Pd, 11.8 eV of Pd, and 33 eV of Pd. Neutron-capture rays were measured with a large Ge detector array called "4Ge spectrometer", which is one component of the Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) installed at the neutron Beam Line No.4 (BL04) of the Materials and Life science experimental Facility (MLF) in the Japan Proton Accelerator Research Complex (J-PARC). This paper presents new findings on resonance assignments of Pd, and the preliminary cross section.
木村 敦; 藤井 俊行*; 福谷 哲*; 古高 和禎; 後神 進史*; 原 かおる; 原田 秀郎; 廣瀬 健太郎; 堀 順一*; 井頭 政之*; et al.
Journal of Nuclear Science and Technology, 49(7-8), p.708 - 724, 2012/07
被引用回数:51 パーセンタイル:95.95(Nuclear Science & Technology)The neutron-capture cross sections of Cm and Cm were measured in the energy range of 1-300 eV with an array of large germanium detectors in the ANNRI at J-PARC/MLF. The resonances at around 7.7 and 16.8 eV of Cm and 4.3 and 15.3 eV of Cm were observed in capture reactions for the first time. The uncertainties of the obtained cross sections are 5.8% at the top of the first resonance of Cm and 6.6% at that of Cm. Resonance analyses were performed for low-energy ones using the code SAMMY. The prompt -ray spectra of Cm and Cm were also obtained. Eight and five new prompt -rays emitted were observed in the Cm(n,) and Cm(n,) reactions, respectively.
初川 雄一; 永井 泰樹; 金 政浩; 瀬川 麻里子; 原田 秀郎; 岩本 修; 岩本 信之; 落合 謙太郎; 高倉 耕祐; 今野 力; et al.
Proceedings in Radiochemistry, 1(1), p.327 - 329, 2011/09
核医学において最もよく用いられているTcの供給は危機に面しており、新たな製造プロセスの開発は喫緊の問題である。本研究はTcをFNSより発生される14MeV高速中性子を用いて効率よく製造することを提案するものであり、試験的に作成したチタン酸ゲルを用いたTc/Moジェネレータについても併せて発表を行う。