※ 半角英数字
 年 ~ 
検索結果: 141 件中 1件目~20件目を表示


Initialising ...



Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...


Initialising ...



Experimental analysis on dynamics of liquid molecules adjacent to particles in nanofluids

橋本 俊輔*; 中島 健次; 菊地 龍弥*; 蒲沢 和也*; 柴田 薫; 山田 武*

Journal of Molecular Liquids, 342, p.117580_1 - 117580_8, 2021/11




Liquid-like thermal conduction in intercalated layered crystalline solids

Li, B.; Wang, H.*; 川北 至信; Zhang, Q.*; Feygenson, M.*; Yu, H. L.*; Wu, D.*; 尾原 幸治*; 菊地 龍弥*; 柴田 薫; et al.

Nature Materials, 17(3), p.226 - 230, 2018/03

 被引用回数:71 パーセンタイル:96.98(Chemistry, Physical)

As a generic property, all substances transfer heat through microscopic collisions of constituent particles. A solid conducts heat through both transverse and longitudinal acoustic phonons, but a liquid employs only longitudinal vibrations. As a result, a solid is usually thermally more conductive than a liquid. In canonical viewpoints, such a difference also serves as the dynamic signature distinguishing a solid from a liquid. Here, we report liquid-like thermal conduction observed in the crystalline AgCrSe$$_{2}$$. The transverse acoustic phonons are completely suppressed by the ultrafast dynamic disorder while the longitudinal acoustic phonons are strongly scattered but survive, and are thus responsible for the intrinsically ultralow thermal conductivity. This scenario is applicable to a wide variety of layered compounds with heavy intercalants in the van der Waals gaps, manifesting a broad implication on suppressing thermal conduction. These microscopic insights might reshape the fundamental understanding on thermal transport properties of matter and open up a general opportunity to optimize performances of thermoelectrics.


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

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



Temperature of thermal spikes induced by swift heavy ions

松崎 勝太*; 林 宏明*; 中嶋 薫*; 松田 誠; 左高 正雄*; 辻本 将彦*; Toulemonde, M.*; 木村 健二*

Nuclear Instruments and Methods in Physics Research B, 406(Part B), p.456 - 459, 2017/09

 被引用回数:3 パーセンタイル:40.62(Instruments & Instrumentation)

Few-nm sized gold, platinum and palladium nanoparticles were deposited on amorphous silicon nitride films. These films were irradiated with 420 MeV Au and 100 MeV Xe ions. Temperature distributions of thermal spikes produced by these ions were evaluated by observing desorption of the nanoparticles from the target surfaces upon ion impact. It was found that the temperature of the thermal spike produced by 420 MeV Au is higher than 100 MeV Xe. The observed temperature of the thermal spike at the entrance surface is slightly lower than that at the exit surface both for 420 MeV Au and 100 MeV Xe ions. These results can be well explained by the inelastic thermal spike model.


Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex, 3; Neutron devices and computational and sample environments

坂佐井 馨; 佐藤 節夫*; 瀬谷 智洋*; 中村 龍也; 藤 健太郎; 山岸 秀志*; 曽山 和彦; 山崎 大; 丸山 龍治; 奥 隆之; et al.

Quantum Beam Science (Internet), 1(2), p.10_1 - 10_35, 2017/09



Polar rotor scattering as atomic-level origin of low mobility and thermal conductivity of perovskite CH$$_{3}$$NH$$_{3}$$PbI$$_{3}$$

Li, B.; 川北 至信; Liu, Y.*; Wang, M.*; 松浦 直人*; 柴田 薫; 河村 聖子; 山田 武*; Lin, S.*; 中島 健次; et al.

Nature Communications (Internet), 8, p.16086_1 - 16086_9, 2017/06

 被引用回数:52 パーセンタイル:91.93(Multidisciplinary Sciences)

Perovskite CH$$_{3}$$NH$$_{3}$$PbI$$_{3}$$ exhibits outstanding photovoltaic performances, but the understanding of the atomic motions remains inadequate even though they take a fundamental role in transport properties. Here, we present a complete atomic dynamic picture consisting of molecular jumping rotational modes and phonons, which is established by carrying out high-resolution time-of-flight quasi-elastic and inelastic neutron scattering measurements in a wide energy window ranging from 0.0036 to 54 meV on a large single crystal sample, respectively. The ultrafast orientational disorder of molecular dipoles, activated at approximately 165 K, acts as an additional scattering source for optical phonons as well as for charge carriers. It is revealed that acoustic phonons dominate the thermal transport, rather than optical phonons due to sub-picosecond lifetimes. These microscopic insights provide a solid standing point, on which perovskite solar cells can be understood more accurately and their performances are perhaps further optimized.


Inelastic and quasi-elastic neutron scattering spectrometers in J-PARC

瀬戸 秀紀; 伊藤 晋一; 横尾 哲也*; 遠藤 仁*; 中島 健次; 柴田 薫; 梶本 亮一; 河村 聖子; 中村 充孝; 川北 至信; et al.

Biochimica et Biophysica Acta; General Subjects, 1861(1), p.3651 - 3660, 2017/01

 被引用回数:21 パーセンタイル:80.69(Biochemistry & Molecular Biology)



Temperature of thermal spikes in amorphous silicon nitride films produced by 1.11 MeV C$$_{60}^{3+}$$ impacts

北山 巧*; 中嶋 薫*; 鈴木 基史*; 鳴海 一雅; 齋藤 勇一; 松田 誠; 左高 正雄*; 辻本 将彦*; 磯田 正二*; 木村 健二*

Nuclear Instruments and Methods in Physics Research B, 354, p.183 - 186, 2015/07

 被引用回数:2 パーセンタイル:22.25(Instruments & Instrumentation)

According to an inelastic-thermal-spike (i-TS) model, which is regarded as the most promising among several models proposed to explain the formation of an ion track, a part of the energy deposited to electrons in a solid by a swift heavy ion is gradually transferred to target atoms via electron-phonon coupling. The temperature of target atoms rises along the ion path and consequently an ion track is formed when the temperature exceeds the melting point. Therefore, the temperature of target atoms along the ion path is regarded as a key parameter for the i-TS model; however, such a spatiotemporally-localized temperature is difficult to measure because the processes involved occur in a very short period ($$<$$ 10$$^{-10}$$ s) and in a very localized area. In this study, the temperature of target atoms along the ion path is estimated experimentally with transmission-electron-microscope (TEM) observation of desorption of Au nanoclusters (the melting point $$sim$$1300 K) on an amorphous Si$$_{3}$$N$$_{4}$$ thin film under 1.1-MeV C$$_{60}^{3+}$$-ion irradiation to the fluence of $$sim$$5$$times$$10$$^{10}$$ ions/cm$$^{2}$$. TEM images show that Au nanoclusters, deposited at the areal density of 1.16$$times$$10$$^{12}$$ particles/cm$$^{2}$$, disappear in a surface area with a diameter of $$sim$$20 nm around each ion track, whose diameter is $$sim$$4 nm, after irradiation. This indicates that the temperature at the film surface rises locally to at least 1300 K by the ion bombardment.


Sputtering of SiN films by 540 keV C$$_{60}$$$$^{2+}$$ ions observed using high-resolution Rutherford backscattering spectroscopy

中嶋 薫*; 森田 陽亮*; 北山 巧*; 鈴木 基史*; 鳴海 一雅; 齋藤 勇一; 辻本 将彦*; 磯田 正二*; 藤居 義和*; 木村 健二*

Nuclear Instruments and Methods in Physics Research B, 332, p.117 - 121, 2014/08

 被引用回数:7 パーセンタイル:55.77(Instruments & Instrumentation)

Our previous observation that an impact of sub-MeV C$$_{60}$$ ion makes an ion track in a thin amorphous silicon nitride (a-SiN) film suggests emission of thousands of atoms from the cylindrical region. Sputtering yields of a-SiN films by C$$_{60}$$ ions were evaluated in order to confirm this observation. A-SiN films deposited on Si(001) were irradiated with 540-keV C$$_{60}$$$$^{2+}$$ ions at fluences from 2.5$$times$$10$$^{11}$$ to 1$$times$$10$$^{14}$$ ions/cm$$^{2}$$. The compositional depth profiles of the irradiated samples were measured with high-resolution Rutherford backscattering spectroscopy, and the sputtering yields were estimated at 3900 $$pm$$ 500 N atoms/ion and 1500 $$pm$$ 1000 Si atoms/ion. The sputtering yield of N was two orders of magnitude larger than the elastic sputtering yield by the SRIM code or than the measured electronic sputtering yield of a-SiN by 50-MeV Cu ions previously reported. Such a large sputtering yield cannot be explained either by the elastic sputtering or by the electronic sputtering. However, an estimation of the synergistic effect based on the inelastic thermal spike model roughly explains the observed large sputtering yield, indicating that the synergistic effect of the nuclear and electronic stopping powers plays an important role.


Transmission secondary ion mass spectrometry using 5 MeV C$$_{60}$$$$^{+}$$ ions

中嶋 薫*; 永野 賢悟*; 鈴木 基史*; 鳴海 一雅; 齋藤 勇一; 平田 浩一*; 木村 健二*

Applied Physics Letters, 104(11), p.114103_1 - 114103_4, 2014/03

 被引用回数:5 パーセンタイル:26.55(Physics, Applied)

In the secondary ion mass spectrometry (SIMS), use of cluster ions has an advantage of having a high sensitivity of intact large molecular ions over monatomic ions. This paper presents further yield enhancement of the intact biomolecular ions with measuring the secondary ions emitted from a self-supporting thin film in the forward direction, which is the same direction as primary beams. Phenylalanine amino-acid films deposited on self-supporting thin Si$$_{3}$$N$$_{4}$$ films were bombarded with 5-MeV C$$_{60}$$$$^{+}$$ ions. Secondary ions emitted in the forward and backward directions were measured under the bombardments of the SiN and phenylalanine sides, respectively. The yield of intact phenylalanine molecular ions emitted in the forward direction is about one order of magnitude larger than the backward direction, while fragment ions of phenylalanine molecules are suppressed. This suggests a large potential of transmission cluster-ion SIMS for the analysis of biological materials.


Surface effect on ion track formation in amorphous Si$$_{3}$$N$$_{4}$$ films

森田 陽亮*; 中嶋 薫*; 鈴木 基史*; 鳴海 一雅; 齋藤 勇一; 石川 法人; 北條 喜一; 辻本 将彦*; 磯田 正二*; 木村 健二*

Nuclear Instruments and Methods in Physics Research B, 315, p.142 - 145, 2013/11

 被引用回数:8 パーセンタイル:59.34(Instruments & Instrumentation)

Thin films of amorphous Si$$_{3}$$N$$_{4}$$ (thickness 5-30 nm) were irradiated with 360-720 keV C$$_{60}$$$$^{2+}$$ ions in order to investigate ion track formation. Ion tracks were observed with transmission electron microscopy (TEM) and high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). The length and the radial density profile of the track were measured for various combinations of the film thickness and the energy of C$$_{60}$$$$^{2+}$$ ions. The length of the ion track produced in a 30-nm film was found shorter than that in a 20-nm film for the same projectile energy, which indicates that there is surface effect on track formation. This can be qualitatively understood in terms of the energy dissipation process. The observed radial density profile also depends on the film thickness: The apparent density reduction increases with decreasing film thickness. The result can be explained by surface cratering.


Cluster effect on projected range of 30-keV C$$_{60}$$$$^{+}$$ in silicon

森田 陽亮*; 中嶋 薫*; 鈴木 基史*; 鳴海 一雅; 齋藤 勇一; 木村 健二*

JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 167, 2013/01

本研究では、これまで飛程に対するクラスター効果がそれほど大きくないと考えられてきた$${it M}$$$$_{1}$$$$<$$$${it M}$$$$_{2}$$の場合について、それを実験的に明らかにする。ここで$${it M}$$$$_{1}$$, $${it M}$$$$_{2}$$はそれぞれ入射イオン及び標的を構成する元素の質量数である。あらかじめ表面に非晶質層を作製したSiウェファーに、30keV C$$_{60}$$$$^{+}$$と0.5keV C$$^{+}$$を室温で2$$times$$10$$^{15}$$ atoms/cm$$^{2}$$注入し、注入した炭素の深さ分布を、高分解能ラザフォード後方散乱法を用いて測定した。C$$_{60}$$注入に対するCの平均深さが6.1nmである一方、C$$^{+}$$注入の場合は4.0nmとなり、投影飛程に対する顕著なクラスター効果を観測した。


Recent developments of instruments in a spallation neutron source at J-PARC and those prospects in the future

新井 正敏; 梶本 亮一; 中村 充孝; 稲村 泰弘; 中島 健次; 柴田 薫; 高橋 伸明; 鈴木 淳市*; 高田 慎一; 山田 武*; et al.

Journal of the Physical Society of Japan, 82(Suppl.A), p.SA024_1 - SA024_14, 2013/01

 被引用回数:6 パーセンタイル:47.11(Physics, Multidisciplinary)

J-PARC中性子散乱施設(1MW, 25Hzの短パルス中性子源)での実験装置の開発について記述したものである。大強度の結合型減速材を利用し、パルス整形チョッパーの利用により、新たな概念をもとにして高分解能装置の開発を行った。また、イベント・レコーディングによるデータ集積系の開発により、多重入射エネルギー法の実現も行った。さらに、回折計の高度化についても述べている。


Direct observation of fine structure in ion tracks in amorphous Si$$_{3}$$N$$_{4}$$ by TEM

中嶋 薫*; 森田 陽亮*; 鈴木 基史*; 鳴海 一雅; 齋藤 勇一; 石川 法人; 北條 喜一; 辻本 政彦*; 磯田 正二*; 木村 健二*

Nuclear Instruments and Methods in Physics Research B, 291, p.12 - 16, 2012/11

 被引用回数:12 パーセンタイル:69.17(Instruments & Instrumentation)

非晶質Si$$_{3}$$N$$_{4}$$薄膜(厚さ20nm)に120-720keV C$$_{60}$$$$^{+, 2+}$$イオンを照射し、透過型電子顕微鏡(TEM)で観察した。その結果、結晶性材料と違って像にコントラストがつきにくい非晶質材料中に形成されたイオントラックをTEMで直接観測できた。さらに、定量的な解析のため、高角散乱環状暗視野走査透過型顕微鏡法(HAADF-STEM)を用いてイオントラックを観察した。その結果、イオントラックの構造は低密度コア(半径約2.5nm)と高密度シェル(幅約2.5nm)からなり、高エネルギー重イオン照射によって非晶質SiO$$_{2}$$中に形成されたイオントラックを小角X線散乱法(SAXS)で観察した結果とよく似ていることがわかった。観測されたイオントラックは表面効果の影響を受けている可能性があるものの、今回の結果は、TEMとHAADF-STEMが非晶質材料中のイオントラックの微細構造を直接観察できることを示すものである。


Repetition Rate Multiplication: RRM, an advanced measuring method planed for the backscattering instrument, ${it DNA}$ at the MLF, J-PARC

高橋 伸明; 柴田 薫; 川北 至信; 中島 健次; 稲村 泰弘; 中谷 健; 中川 洋; 藤原 悟; 佐藤 卓*; 筑紫 格*; et al.

Journal of the Physical Society of Japan, 80(Suppl.B), p.SB007_1 - SB007_4, 2011/12

 被引用回数:5 パーセンタイル:41.54(Physics, Multidisciplinary)

A TOF-BSS named ${it DNA}$ has been under construction on BL02 in the MLF of J-PARC. We have estimated expected performances of several candidates under realistic neutron source parameters at MLF. The expected neutron intensity under comparable energy resolutions of the ${it DNA}$-type is 2.6 times higher than that of the BASIS-type. Consequently, we have chosen the CM with pulse-shaping device for ${it DNA}$. Pulse-shaping is a good technique from a view point of a variability of resolution. On the other hand, a neutron energy band passing through the pulse-shaping chopper is limited and thus scanning range with one phase of the chopper is narrow. Of course, ${it DNA}$ also can access larger energy transfers by appropriate phasing of the pulse-shaping chopper. In addition, ${it DNA}$ will be able to utilize Repetition Rate Multiplication (RRM). RRM is essentially a way to employ multiple pulse-shaped incident neutron beams to effectively increase neutron counting time to more efficiently measure the inelastic region. In this presentation we will show the chopper sequence and introduce the RRM mode of the forthcoming backscattering spectrometer ${it DNA}$ in detail.


Cluster effect on projected range of 30 keV C$$_{60}$$$$^{+}$$ in silicon

森田 陽亮*; 中嶋 薫*; 鈴木 基史*; 鳴海 一雅; 齋藤 勇一; Vandervorst, W.*; 木村 健二*

Nuclear Instruments and Methods in Physics Research B, 269(19), p.2080 - 2083, 2011/10

 被引用回数:6 パーセンタイル:48.42(Instruments & Instrumentation)

あらかじめ表面に非晶質層を作製したSiウェファーに、30keV C$$_{60}$$$$^{+}$$と0.5keV C$$^{+}$$を室温で2$$times$$10$$^{15}$$ atoms/cm$$^{2}$$注入し、注入した炭素の深さ分布を、高分解能ラザフォード後方散乱法を用いて測定した。C$$_{60}$$$$^{+}$$注入に対するCの平均深さは6.1nmであり、一方、C$$^{+}$$注入の場合は4.0nmとなり、投影飛程に対する顕著なクラスター効果を観測した。


AMATERAS; A Cold-neutron disk chopper spectrometer

中島 健次; 河村 聖子; 菊地 龍弥; 中村 充孝; 梶本 亮一; 稲村 泰弘; 高橋 伸明; 相澤 一也; 鈴谷 賢太郎; 柴田 薫; et al.

Journal of the Physical Society of Japan, 80(Suppl.B), p.SB028_1 - SB028_6, 2011/05

 被引用回数:90 パーセンタイル:94.38(Physics, Multidisciplinary)



The Fermi chopper spectrometer 4SEASONS at J-PARC

梶本 亮一; 中村 充孝; 稲村 泰弘; 水野 文夫; 中島 健次; 河村 聖子; 横尾 哲也*; 中谷 健; 丸山 龍治; 曽山 和彦; et al.

Journal of the Physical Society of Japan, 80(Suppl.B), p.SB025_1 - SB025_6, 2011/01

 被引用回数:71 パーセンタイル:92.29(Physics, Multidisciplinary)

4SEASONS is a Fermi chopper spectrometer, which is in operation in Materials and Life Science Experimental Facility (MLF), J-PARC. It is intended to provide high-efficiency measurement of weak inelastic signals on novel spin and lattice dynamics with thermal neutrons. For this purpose, the spectrometer utilizes the coupled moderator and advanced instrumental design such as an elliptic-shaped converging neutron guide with high-critical angle supermirrors inside, long (2.5 m) position sensitive detectors, and a Fermi chopper feasible for multiple-incident-energy (multi-$$E_{rm i}$$) measurement with the repetition rate multiplication technique. Here we show detailed design of the spectrometer, evaluation of its performance, and some examples of measurements.


Proceedings of the Workshop on "Possible Scientific View from New Neutron Spectroscopy Opportunities in J-PARC"; 8-9 July 2009, Ibaraki Quantum Beam Research Center, Multi-Purpose Hall, Tokai Plaza Caf$'e$, Tokai, Ibaraki, Japan

中島 健次; 柴田 薫; 梶本 亮一

JAEA-Review 2010-027, 140 Pages, 2010/08





今井 良行; 中島 隼人; 久保 真治; 小貫 薫

化学工学論文集, 36(1), p.70 - 73, 2010/01

 被引用回数:5 パーセンタイル:25.23(Engineering, Chemical)


141 件中 1件目~20件目を表示