検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年
検索結果: 164 件中 1件目~20件目を表示

発表形式

Initialising ...

選択項目を絞り込む

掲載資料名

Initialising ...

発表会議名

Initialising ...

筆頭著者名

Initialising ...

キーワード

Initialising ...

使用言語

Initialising ...

発行年

Initialising ...

開催年

Initialising ...

選択した検索結果をダウンロード

論文

KeV-neutron capture cross-section measurement of $$^{197}$$Au with a Cr-filtered neutron beam at the ANNRI beamline of MLF/J-PARC

Rovira Leveroni, G.; 木村 敦; 中村 詔司; 遠藤 駿典; 岩本 修; 岩本 信之; 片渕 竜也*; 児玉 有*; 中野 秀仁*; 佐藤 八起*; et al.

Journal of Nuclear Science and Technology, 59(5), p.647 - 655, 2022/05

Cr-filtered keV-neutron experiments were performed in the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) beamline in the Materials and Life Science (MLF) facility of the Japan Proton Accelerator Research Complex (J-PARC) to measure the neutron capture cross-section of $$^{197}$$Au. The energy range of the neutron filtering system at ANNRI was extended through the use of 15 cm of $$^{nat}$$Cr as filter material to tailor quasi-monochromatic neutron peaks with averaged neutron energies of 133.4 and 45.0 keV. The performance of the $$^{nat}$$Cr filter assembly was evaluated by means of experimental capture and transmission analyses, together with the use of Monte-Carlo simulations. The present $$^{197}$$Au neutron capture cross-section results provide agreement within uncertainties with the JENDL-4.0 standard evaluated library and the IAEA standard data library further demonstrating the capabilities of the neutron filtering system at ANNRI.

論文

KeV-region analysis of the neutron capture cross-section of $$^{237}$$Np

Rovira Leveroni, G.; 片渕 竜也*; 登坂 健一*; 松浦 翔太*; 児玉 有*; 中野 秀仁*; 岩本 修; 木村 敦; 中村 詔司; 岩本 信之

Journal of Nuclear Science and Technology, 59(1), p.110 - 122, 2022/01

Neutron capture cross-section measurements for $$^{237}$$Np have been conducted with the Accurate Neutron Nucleus Reaction Measurement Instrument (ANNRI) at the Materials and Life Science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC) using neutrons with energy ranging from thermal energy to 1 MeV. A Time of Flight (TOF) method using a NaI(Tl) detector was employed for these measurements and the data were analyzed based on the pulse-height weighting technique in order to derive the neutron capture cross-section. The absolute capture cross-section was determined using the whole shape of the first resonance from JENDL-4.0 together with the total neutron flux derived from a $$^{197}$$Au sample measurement in which the first resonance was completely saturated. Both normalization techniques present agreement within 2%. The present results are also compared evaluated data libraries. There is a discrepancy of 10-25% discrepancy from 0.5 to 20 keV with JENDL-4.0. Nonetheless, above this energy, the JENDL-4.0 seems to reproduce the present data better as the results agree within uncertainties up to 500 keV. The cross-section results contain errors below 4% from 0.5 to 30 keV. However, the total uncertainty increases to over 8% over that energy. Along with the cross section measurement, theoretical calculations were performed to reproduce the present results.

論文

Measurements of the neutron capture cross section of $$^{243}$$Am around 23.5 keV

児玉 有*; 片渕 竜也*; Rovira Leveroni, G.; 木村 敦; 中村 詔司; 遠藤 駿典; 岩本 信之; 岩本 修; 堀 順一*; 芝原 雄司*; et al.

Journal of Nuclear Science and Technology, 58(11), p.1159 - 1164, 2021/11

The neutron capture cross section of $$^{243}$$Am was measured with a pulsed neutron beam from a spallation neutron source of the Japan Proton Accelerator Research Complex. A Fe neutron beam filter was used to make the incident neutron beam mono-energetic around 23.5 keV. The neutron capture $$gamma$$-rays were detected with a NaI(Tl) detector. The pulse height weighting technique was employed to derive the neutron capture cross section from the pulse height spectrum. The cross section was determined relative to the capture cross section of $$^{197}$$Au of JENDL-4.0. The neutron capture cross section of $$^{243}$$Am was determined with a smaller uncertainty than previous measurements. The previous measurements and the JENDL-4.0 cross sections were found to be lower than the present result.

論文

Neutron beam filter system for fast neutron cross-section measurement at the ANNRI beamline of MLF/J-PARC

Rovira Leveroni, G.; 木村 敦; 中村 詔司; 遠藤 駿典; 岩本 修; 岩本 信之; 片渕 竜也*; 寺田 和司*; 児玉 有*; 中野 秀仁*; et al.

Nuclear Instruments and Methods in Physics Research A, 1003, p.165318_1 - 165318_10, 2021/07

 被引用回数:0 パーセンタイル:0.03(Instruments & Instrumentation)

A neutron filtering system has been introduced in the Accurate Neutron-Nucleus Reaction Measurement Instrument (ANNRI) beamline in the Material and Life Science (MLF) building of the Japan Proton Accelerator Research Complex (JPARC) in order to produce quasi-monoenergetic neutron beams. The filtered neutron spectrum by the filter assemblies was analyzed by means of capture and transmission measurements and also by Monte Carlo simulations using PHITS. The characteristics of the filtered neutron beam are discussed alongside its viability in future applications for neutron cross-section measurements in the fast neutron region.

論文

Initial oxidation kinetics of Si(113)-(3$$times$$2) investigated using supersonic seeded molecular beams

大野 真也*; 田中 一馬*; 小玉 開*; 田中 正俊*; 吉越 章隆; 寺岡 有殿*

Surface Science, 697, p.121600_1 - 121600_6, 2020/07

放射光高分解能光電子分光法によってシリコン(113)表面の初期酸化を調べた。本研究では、Si2pとO1s光電子スペクトルから酸化物の厚さおよび組成を評価するとともにSiO$$_{2}$$/Si界面のひずみを評価した。Si2pから酸化成分(Si$$^{1+}$$, Si$$^{2+}$$, Si$$^{3+}$$, Si$$^{4+}$$)を分析した。また、O1sスペクトルは、低結合エネルギー成分(LBC)および高結合エネルギー成分(HBC)に分離された。非熱酸化プロセスを調べるために、並進運動エネルギー($$E_{rm t}$$)を高めることが可能な超音速シード分子ビーム(SSMB)を使った。酸化物の品質と酸化速度が、$$E_{rm t}$$を変えることで大きく変わることが明らかになった。

論文

Q dependence of magnetic resonance mode on FeTe$$_{0.5}$$Se$$_{0.5}$$ studied by inelastic neutron scattering

石角 元志*; 樹神 克明; 梶本 亮一; 中村 充孝; 稲村 泰弘; 池内 和彦*; Ji, S.*; 新井 正敏*; 社本 真一

Condensed Matter (Internet), 4(3), p.69_1 - 69_10, 2019/09

中性子非弾性散乱により観測された磁気共鳴モードのQ依存性という初めての手法で、FeTe$$_{0.5}$$Se$$_{0.5}$$の超伝導対称性がs$$pm$$波であることを実験的に示した。

論文

Magnetic, thermal, and neutron diffraction studies of a coordination polymer; bis(glycolato)cobalt(II)

中根 僚宏*; 米山 翔太*; 兒玉 健*; 菊地 耕一*; 中尾 朗子*; 大原 高志; 東中 隆二*; 松田 達磨*; 青木 勇二*; 藤田 渉*

Dalton Transactions (Internet), 48(1), p.333 - 338, 2019/01

 被引用回数:1 パーセンタイル:11.81(Chemistry, Inorganic & Nuclear)

The two-dimensional quadratic lattice magnet, bis(glycolato)cobalt(II) ([Co(HOCH$$_{2}$$CO$$_{2}$$)$$_{2}$$]), showed anti-ferromagnetic ordering at 15.0 K and an abrupt increase in magnetisation at H = 22 600 Oe and 2 K, thereby acting as a metamagnet. Neutron diffraction studies suggested that the magnetic moment vectors of the Co(II) ions had an amplitude of 3.59 mB and were not aligned in a fully antiparallel fashion to those of their neighbours, which caused canting between the magnetic moment vectors in the sheet. The canting angle was determined to be 7.1deg. Canting induced net magnetisation in the sheet, but this magnetisation was cancelled between sheets. The magnetisations in the sheets were oriented parallel to the magnetic field at the critical magnetic field.

論文

Local disorder in proton conductor BaSn$$_{0.5}$$In$$_{0.5}$$O$$_{2.75}$$ analyzed by neutron diffraction/ atomic pair distribution function

井川 直樹; 樹神 克明; 田口 富嗣*; 吉田 幸彦*; 松川 健*; 星川 晃範*; 石垣 徹*

Transactions of the Materials Research Society of Japan, 43(6), p.329 - 332, 2018/12

プロトン伝導体BaSn$$_{0.5}$$In$$_{0.5}$$O$$_{2.75}$$の電気的特性に及ぼす結晶構造の影響を理解するため、本材料における局所構造乱れを中性子回折/原子対分布関数(PDF)法を用いて解析した。本材料の局所構造は、${it r}$ $$>$$ 0.6nmの原子間距離範囲内では、リートベルト解析によって推定された平均構造と同様の立方晶構造(空間群$${it Pm}$$$$overline{3}$$$${it m}$$))である。一方、${it r}$ $$<$$ 0.6nmの範囲のPDFプロファイルは、立方晶構造よりも空間群${it P}$4/${it mmm}$の正方晶構造によって良い一致をみた。これらの結果は、格子内の局所構造乱れの存在を示している。本発表では、BaSn$$_{0.5}$$In$$_{0.5}$$O$$_{2.75}$$の平均構造と局所構造との関係の詳細について考察する。

論文

High-energy spin fluctuation in low-T$$_{c}$$ iron-based superconductor LaFePO$$_{0.9}$$

石角 元志*; 社本 真一; 樹神 克明; 梶本 亮一; 中村 充孝; Hong, T.*; Mutka, H.*

Scientific Reports (Internet), 8, p.16343_1 - 16343_6, 2018/11

 被引用回数:2 パーセンタイル:29.78(Multidisciplinary Sciences)

磁気揺らぎはBCS理論に従わない非従来型超伝導で最も可能性のある機構として重要な役割を担うと考えられてきた。今回、これまで磁気ゆらぎが見つかっていない5Kという低い超伝導転移温度の鉄リン系超伝導体LaFePO$$_{0.9}$$で、30-50meVの高エネルギーで磁気ゆらぎを見つけた。これはこれまで考えられてきた高エネルギー磁気揺らぎで、高い超伝導転移温度になるという考えとは矛盾することから、超伝導機構の理解に向けて重要な発見である。

論文

Nanoscale ice-type structural fluctuation in spinel titanates

鳥越 秀平*; 服部 崇幸*; 樹神 克明; 本田 孝志*; 佐賀山 基*; 池田 一貴*; 大友 季哉*; 仁谷 浩明*; 阿部 仁*; 村川 寛*; et al.

Physical Review B, 98(13), p.134443_1 - 134443_7, 2018/10

 被引用回数:2 パーセンタイル:16.65(Materials Science, Multidisciplinary)

In the spinel titanate MgTi$$_2$$O$$_4$$, the tetragonal phase collapses upon substitution of a tiny amount of Mg ion at the Ti site, and the cubic phase with the geometrical frustration is resurrected. The atomic pair distribution function (PDF) and the extended X-ray absorption fine structure (EXAFS) reveal the nanoscale structural fluctuation, in which the Ti atomic displacement has the two-in two-out configuration in the cubic phase. We argue that the geometrical frustration plays an essential role in the collapse of the tetragonal phase and the resultant nanoscale ice-type structural fluctuation.

論文

Neutron scattering study of yttrium iron garnet

社本 真一; 伊藤 孝; 大西 弘明; 山内 宏樹; 稲村 泰弘; 松浦 直人*; 赤津 光洋*; 樹神 克明; 中尾 朗子*; 茂吉 武人*; et al.

Physical Review B, 97(5), p.054429_1 - 054429_9, 2018/02

 被引用回数:10 パーセンタイル:63.24(Materials Science, Multidisciplinary)

イットリウム鉄ガーネットの核および磁気構造と全マグノン分散を中性子散乱により調べた。低エネルギーの分散は強磁性マグノンで期待されるように14meVまで2次関数の分散を示した。$$q$$積分した動的磁化率$$chi$$"($$E$$)の虚部は低エネルギーで平方根のエネルギー依存性を示した。$$chi$$"($$E$$)から絶対値でマグノン状態密度を求めた。その値は理論的に予想されるマグノン分散でひとつのカラリティーモードに対応する。

論文

Local structural analysis of half-metallic ferromagnet CrO$$_2$$

樹神 克明; 池田 一貴*; 礒部 正彦*; 武田 晃*; 伊藤 正行*; 上田 寛*; 社本 真一; 大友 季哉*

Journal of the Physical Society of Japan, 85(9), p.094709_1 - 094709_5, 2016/09

 被引用回数:1 パーセンタイル:13.94(Physics, Multidisciplinary)

We have performed powder neutron diffraction on the half-metallic ferromagnet CrO$$_2$$ which has a rutile-type crystal structure with a tetragonal unit cell. Although the powder diffraction pattern can be fitted by the reported crystal structure including a single Cr site, the atomic pair distribution function (PDF) can be fitted by the structural model with an orthorhombic unit cell including two kinds of inequivalent Cr sites. The difference between the valences of the two inequivalent Cr sites, $$delta$$ of Cr$$^{+4pmdelta}$$, estimated from the local structural parameters is about 0.06. The shapes of the two CrO$$_6$$ octahedra are slightly different, suggesting the short-range orbital ordering of the Cr 3$$d$$ orbitals. The lattice distortion and the improvement of the fitting to the PDF obtained using the locally distorted structure model are apparent in the region below about 10 ${AA}$, suggesting that the domain size or correlation length of the locally distorted structure is about 10 ${AA}$, roughly corresponding to the size of two unit cells.

論文

Observation of all-in type tetrahedral displacements in nonmagnetic pyrochlore niobates

鳥越 秀平*; 石本 祐太朗*; 青石 優平*; 村川 寛*; 松村 大樹; 吉井 賢資; 米田 安宏; 西畑 保雄; 樹神 克明; 富安 啓輔*; et al.

Physical Review B, 93(8), p.085109_1 - 085109_5, 2016/02

 被引用回数:4 パーセンタイル:26.78(Materials Science, Multidisciplinary)

We observed all-in type Nb tetrahedral displacement in nonmagnetic pyrochlore niobates A$$_{2}$$Nb$$_{2}$$O$$_{7}$$ (A = Nd$$_{0.5}$$Ca$$_{0.5}$$ and Y$$_{0.5}$$Ca$$_{0.5}$$) through the analysis of the neutron pair distribution function and the extended X-ray absorption function spectroscopy. The all-in type Nb tetrahedral displacement, which has the character of a charge singlet state, is driven by the formation of the bonding orbital. The diffuse scattering in the X-ray diffraction, which has the resonant component in the Nb $$L$$3 edge, indicates that the all-in type Nb tetrahedral displacement has the periodicity with its short-range correlation.

論文

Revealing the second harmonic generation in a femtosecond laser-driven cluster-based plasma by analyzing shapes of Ar XVII spectral lines

Oks, E.*; Dalimier, E.*; Faenov, A.*; Pikuz, T.*; 福田 祐仁; Andreev, A.*; Koga, J. K.; 榊 泰直; 小瀧 秀行; Pirozhkov, A. S.; et al.

Optics Express (Internet), 23(25), p.31991 - 32005, 2015/12

 被引用回数:6 パーセンタイル:40.44(Optics)

フェムト秒高強度レーザーをアルゴンクラスターターゲットに照射して生成したプラズマから発生したアルゴンXVIIスペクトルサテライト線のライン形状を詳細に解析することにより、プラズマ中で非線形現象が起こっていることを明らかにし、その結果、照射レーザー光の第二次高調波(SHG)が発生していることを解明した。サテライト線解析の新しい理論を構築し、入射レーザー光の2 %がSHGに変換されていることを明らかにした。この実験結果は、二次元粒子コードを用いたシミュレーション結果とも良い一致を示した。

論文

3D visualization of XFEL beam focusing properties using LiF crystal X-ray detector

Pikuz, T.*; Faenov, A.*; 松岡 健之*; 松山 智至*; 山内 和人*; 尾崎 典雅*; Albertazzi, B.*; 犬伏 雄一*; 矢橋 牧名*; 登野 健介*; et al.

Scientific Reports (Internet), 5, p.17713_1 - 17713_10, 2015/12

 被引用回数:26 パーセンタイル:84.61(Multidisciplinary Sciences)

we report, that by means of direct irradiation of lithium fluoride a (LiF) crystal, in situ 3D visualization of the SACLA XFEL focused beam profile along the propagation direction is realized, including propagation inside photoluminescence solid matter. High sensitivity and large dynamic range of the LiF crystal detector allowed measurements of the intensity distribution of the beam at distances far from the best focus as well as near the best focus and evaluation of XFEL source size and beam quality factor M2. Our measurements also support the theoretical prediction that for X-ray photons with energies $$sim$$10 keV the radius of the generated photoelectron cloud within the LiF crystal reaches about 600 nm before thermalization. The proposed method has a spatial resolution 0.4-2.0 micron for photons with energies 6-14 keV and potentially could be used in a single shot mode for optimization of different focusing systems developed at XFEL and synchrotron facilities.

論文

Crystal structures and magnetic properties of nickel chain compounds PbM$$_2$$Ni$$_6$$Te$$_3$$O$$_{18}$$ (M = Mn, Cd)

土井 貴弘*; 鈴木 遼*; 日夏 幸雄*; 樹神 克明; 井川 直樹

Inorganic Chemistry, 54(22), p.10725 - 10731, 2015/11

 被引用回数:5 パーセンタイル:31.75(Chemistry, Inorganic & Nuclear)

The synthesis, crystal structures, and magnetic properties of the pentanary oxides PbM$$_2$$Ni$$_6$$Te$$_3$$O$$_{18}$$ (M = Mn and Cd) were investigated. These compounds crystallize in a hexagonal structure with space group $$P6_3/m$$, in which the Ni$$^{2+}$$ ions form a zigzag chain along the c axis. From the magnetic susceptibility and specific heat measurements, we found that the PbCd$$_2$$Ni$$_6$$Te$$_3$$O$$_{18}$$ behaves as a low-dimensional magnet due to the intrachain an tiferromagnetic interaction between Ni$$^{2+}$$ ions. Both compounds show a long-range antiferromagnetic ordering at 25.7 K (M = Cd) and 86.0 K (Mn). The magnetic structure of PbMn$$_2$$Ni$$_6$$Te$$_3$$O$$_{18}$$ determined by neutron diffraction measurements is a collinear antiferromagnetic arrangement of Mn$$^{2+}$$ ions in the Mn$$_2$$O$$_9$$ dimeric unit and Ni$$^{2+}$$ ions in the zigzag chain.

論文

Study on the behavior of radiolytically produced hydrogen in a high-level liquid waste tank of a reprocessing plant; Comparison between actual and simulated solutions

衣旗 広志*; 山本 昌彦; 田口 茂郎; 駿河谷 直樹; 佐藤 宗一; 小玉 貴司*; 玉内 義一*; 柴田 勇木*; 安齋 喜代志*; 松岡 伸吾*

Nuclear Technology, 192(2), p.155 - 159, 2015/11

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

東海再処理施設より採取した高放射性廃液を30mL使用して試験を実施した結果、掃気停止状態において、気相部の水素濃度は、水素の爆発下限界である4%よりも低い濃度で平衡状態となっていることが分かった。また、平衡値について、模擬廃液実験から得られたパラメータを用いて計算される予測値と比較した。その結果、平衡値と予測値は同程度のオーダーであり、パラジウムイオンによる水素消費反応が実廃液にも起きていることを確認した。

論文

Using LiF crystals for high-performance neutron imaging with micron-scale resolution

Faenov, A.*; 松林 政仁; Pikuz, T.*; 福田 祐仁; 神門 正城; 安田 良; 飯倉 寛; 野島 健大; 酒井 卓郎; 塩澤 方浩*; et al.

High Power Laser Science and Engineering, 3, p.e27_1 - e27_9, 2015/10

 被引用回数:9 パーセンタイル:53.58(Optics)

This paper describes an overview of our recent discovery - clear demonstration that LiF crystals can be efficiently used as a high-performance neutron imaging detector based on optically stimulated luminescence of color centers generated by neutron irradiation. It is shown that the neutron images we have obtained are almost free from granular noise, have a spatial resolution of 5.4 $$mu$$m and a linear response with a dynamic range of at least 10$$^{3}$$. The high contrast and good sensitivity of LiF crystals allow us to distinguish two holes with less than 2% transmittance difference. We propose to use such detectors in areas where high spatial resolution with high image gradation resolution is needed, including diagnostics of different plasma sources such as laser and z-pinch produced plasmas.

論文

Anisotropic magnetic form factor in a detwinned single crystal of BaFe$$_2$$As$$_2$$

樹神 克明; 石角 元志*; 脇本 秀一; 木方 邦宏*; Lee, C.-H.*; 伊豫 彰*; 永崎 洋*; 社本 真一

Physical Review B, 90(14), p.144510_1 - 144510_5, 2014/10

 被引用回数:1 パーセンタイル:5.56(Materials Science, Multidisciplinary)

We have performed neutron diffraction measurements at 12K on a single crystal of BaFe$$_2$$As$$_2$$, which serves as the parent compound of iron-based superconductor. To investigate the in-plane anisotropy of the magnetic form factor in the antiferromagnetic phase, the single crystal was detwinned. The magnetic structure factor and magnetic form factor are well explained by the spin densities comprising $$3d_{yz}$$ electrons with a fraction of approximately 40% and electrons in the other four $$3d$$ orbitals each with a fraction of approximately 15%. It is a direct observation of the largely anisotropic spin density relative to the small orthorhombic lattice distortion, $$(a-b)/(a+b)$$ $$sim$$ 0.3%.

論文

Superconductivity in noncentrosymmetric iridium silicide Li$$_2$$IrSi$$_3$$

Pyon, S.*; 工藤 一貴*; 松村 純一*; 石井 博文*; 松尾 元太*; 野原 実*; 北條 元*; 岡 研吾*; 東 正樹*; Garlea, V. O.*; et al.

Journal of the Physical Society of Japan, 83(9), p.093706_1 - 093706_5, 2014/09

 被引用回数:26 パーセンタイル:81.51(Physics, Multidisciplinary)

The effects of lithium absorption on the crystal structure and electronic properties of IrSi$$_3$$, a binary silicide with a noncentrosymmetric crystal structure, were studied. X-ray and neutron diffraction experiments revealed that hexagonal IrSi$$_3$$ (space group $$P6_3mc$$) transforms into trigonal Li$$_2$$IrSi$$_3$$ (space group $$P31c$$) upon lithium absorption. The structure of Li$$_2$$IrSi$$_3$$ is found to consist of a planar kagome network of silicon atoms with Li and Ir spaced at unequal distances between the kagome layers, resulting in a polar structure along the c-axis. Li$$_2$$IrSi$$_3$$ exhibited type-II superconductivity with a transition temperature $$T_{rm c}$$ of 3.8 K, displaying a structure type that no previous superconductors have been reported to have.

164 件中 1件目~20件目を表示