研究者詳細 - 清水　裕彦

論文 - 清水　裕彦

分割表示 590 件中 561 - 580 件目／全件表示 >>

Neutron interferometric search for short-range gravity 査読有り

Gudkov V., Greene G., Shimizu H.

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 611 巻 ( 2-3 ) 頁： 153 - 156 2009年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment

We discuss the coherent nature of neutron interactions and properties of low-energy neutrons with the view of the possibility to search for "anomalous" forces with ranges from nuclear sizes up to the macroscopic scale. © 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nima.2009.07.042

Highly polarized very cold neutrons through a permanent magnet quadrupole 査読有り

Taketani, K; Mishima, K; Ino, T; Yoshioka, T; Muto, S; Morishima, T; Shimizu, HM; Oku, T; Suzuki, J; Shinohara, T; Sakai, K; Sato, H; Hirota, K; Otake, Y; Kitaguchi, M; Hino, M; Seki, Y; Iwashita, Y; Yamada, M; Ichikawa, M; Sugimoto, T; Kawasaki, S; Komamiya, S; Kamiya, Y; Otono, H; Yamashita, S; Geltenbort, P

PHYSICA B-CONDENSED MATTER 404 巻 ( 17 ) 頁： 2643 - 2645 2009年9月

掲載種別：研究論文（学術雑誌）出版者・発行元：Physica B Condensed Matter

We obtained highly polarized very cold neutrons through a quadrupole magnet with a large aperture. When neutrons go through a quadrupole magnet, parallel-spin neutrons are attracted to the magnet axis and anti-parallel-spin neutrons are repelled off the axis. Therefore, the neutrons through a sufficiently long quadrupole magnet have completely parallel-spin. At the downstream of the quadrupole magnet, we placed another quadrupole magnet to divide neutrons into two regions depending on their spin directions. We obtained the neutron polarization from the integrated count of the two regions and found it was 99.88±0.09 (stat.)±0.05 (syst.)%. © 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2009.06.045

Development of modulating permanent magnet sextupole lens for focusing of pulsed cold neutrons 査読有り

Yamada, M; Iwashita, Y; Ichikawa, M; Sugimoto, T; Tongu, H; Fujisawa, H; Shimizu, HM; Ino, T; Mishima, K; Taketani, K; Yoshioka, T; Muto, S; Morishima, T; Oku, T; Suzuki, J; Shinohara, T; Sakai, K; Sato, H; Hirota, K; Otake, Y; Seki, Y; Kawasaki, S; Komamiya, S; Kamiya, Y; Otono, H; Yamashita, S; Geltenbort, P

PHYSICA B-CONDENSED MATTER 404 巻 ( 17 ) 頁： 2646 - 2651 2009年9月

掲載種別：研究論文（学術雑誌）出版者・発行元：Physica B Condensed Matter

Modulating permanent magnet sextupole lens (PMSx) for focusing pulsed cold neutrons is under development. The synchronized modulation of its field gradient suppresses the chromatic aberration which arises from the Time Of Flight method. The strength of the magnetic field, the torque, and the rise of temperature during its operation are studied on a fabricated prototype. Experiments on focusing pulsed very cold neutrons (VCN) at ILL (Institute of Laue Langevin, France) were carried out and VCN with around λ=40 Å were focused by the PMSx at a focal length of about 0.5 m. The experimental results are presented in conjunction with the principle of the neutron focusing and the modulating method of the focal strength of permanent magnet lens with the double ring structure. © 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2009.06.132

Design of neutron beamline for fundamental physics at J-PARC BL05 査読有り

Mishima, K; Ino, T; Sakai, K; Shinohara, T; Hirota, K; Ikeda, K; Sato, H; Otake, Y; Ohmori, H; Muto, S; Higashi, N; Morishima, T; Kitaguch, M; Hino, M; Funahashi, H; Shima, T; Suzuki, J; Niita, K; Taketani, K; Seki, Y; Shimizu, HM

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 600 巻 ( 1 ) 頁： 342 - 345 2009年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment

A new beamline for a fundamental physics experiment is under construction at BL05 port in the Materials and Life Science Facility (MLF) at Japan Proton Accelerator Research Complex (J-PARC); this beamline is designed using novel techniques of neutron optics and it is termed "Neutron Optics and Physics." The beam from the moderator is deflected by multi-channel supermirrors and split into three branches for individual experiments. In this study, we have optimized the design of the beam optics and shields using the Monte Carlo simulation package PHITS. The neutron fluxes of beams are expected to be 9.2×10<sup>5</sup> /cm<sup>2</sup>/μstr/s/MW, 1.2×10<sup>9</sup> /cm<sup>2</sup>/s/MW, and 4.0×10<sup>8</sup> /cm<sup>2</sup>/s/MW, with polarization of 99.8%. © 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nima.2008.11.087

Pulsed neutron beam control using a magnetic multiplet lens 査読有り

Oku T., Shinohara T., Suzuki J.i., Pynn R., Shimizu H.M.

Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 600 巻 ( 1 ) 頁： 100 - 102 2009年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment

As a magnetic neutron lens based on a sextupole magnet to focus neutrons has chromatic aberration, it has been proposed that the chromatic aberration can be compensated in the pulsed neutron beam focusing by combining the focusing and defocusing functions of the multiplet magnetic lens system synchronously with time-of-flight (TOF) of neutrons. In this study, we performed numerical simulations on the multiplet magnetic lens system to investigate how a pulsed neutron beam can be controlled on the basis of the TOF method. It was then confirmed that the chromatic aberration can be compensated and the focal condition can be maintained over a certain λ-range by utilizing plural magnetic lenses in series and choosing the focusing and defocusing function of each magnetic lens synchronously with TOF of neutrons. © 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nima.2008.11.055

A CCD-based Pixel Detector with Micron Spatial Resolution for Ultra Cold Neutrons 査読有り

Go Ichikawa, Shinsuke Kawasaki, Sachio Komamiya, Yoshio Kamiya, Tomoyuki Sanuki, Hirohiko M. Shimizu, Masahiro Hino, Masaaki Kitaguchi

2009 IEEE NUCLEAR SCIENCE SYMPOSIUM CONFERENCE RECORD, VOLS 1-5 頁： 1619 - + 2009年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

We have developed a pixel detector for ultra-cold neutrons using a commercial CCD. In order to detect neutrons, a thin neutron converting layer is directly formed on the CCD surface. The detection efficiencies for cold, very-cold and ultra-cold neutrons are measured to be 1.7%, 4.05 +/- 0.08 +/- 0.12% and 40.6 +/- 0.7 +/- 2.8%, respectively. The spatial resolutions were measured to be 2.9 +/- 0.1 mu m for horizontal direction and 4.4 +/- 0.2 mu m for vertical direction. The vertical and horizontal directions are determined by the charge transfer mechanism of CCDs. The details of the pixel detector and its performance tests are described.

DOI： 10.1109/NSSMIC.2009.5402255

Slow Neutron Optics 査読有り

Hirohiko M. Shimizu

TRANSACTIONS OF THE MATERIALS RESEARCH SOCIETY OF JAPAN, VOL 33, NO 3 33 巻 ( 3 ) 頁： 541 - 545 2008年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：MATERIALS RESEARCH SOCIETY JAPAN-MRS-J

We survey the current status of reflective neutron optical devices, compound refractive and magnetic ones for enhancing the effectiveness of the beam utilization to extract physics information of samples.

Highly polarized cold neutron beam obtained by using a quadrupole magnet 査読有り

Oku, T; Yamada, S; Shinohara, T; Suzuki, JI; Mishima, K; Hirota, K; Sato, H; Shimizu, HM

PHYSICA B-CONDENSED MATTER 397 巻 ( 1-2 ) 頁： 188 - 191 2007年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Physica B Condensed Matter

We performed a cold neutron polarization experiment using a polarization device based on a quadrupole magnet. By passing through the aperture of the quadrupole magnet, positive and negative polarity neutrons are accelerated in opposite directions and spatially separated due to the magnetic field gradient. Then, we extracted the one-spin component and analyzed the polarization degree by using a sextupole magnet and position-sensitive detector. As a result, very high neutron polarization degree P=0.9993±0.0025 was obtained. Advantages of the quadrupole magnet as the neutron polarization device and its application to neutron scattering experiments are discussed. © 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2007.02.055

Moire Fringes in a Neutron Spin Interferometer

Taketani Kaoru, Seki Yoshichika, Funahashi Haruhiko, HINO Masahiro, KITAGUCHI Masaaki, OTAKE Yoshie, SHIMIZU Hirohiko M.

Journal of the Physical Society of Japan 76 巻 ( 6 ) 頁： "64008 - 1"-"64008-7" 2007年6月

出版者・発行元：一般社団法人日本物理学会

We have revealed the criterion to observe moire fringes in a neutron spin interferometry. In former studies using wave front division, neutron beam had to be collimated by fine slits. On the other hand, we have succeeded to observe moire fringes with divergence angle of 8.3 mrad using spin polarization division. A model based on partial coherence theory has been developed and verified experimentally. These results will be the basis for neutron wave front manipulation technique using magnetic birefringence.

Moire fringes in a neutron spin interferometer

Taketani, K; Seki, Y; Funahashi, H; Hino, M; Kitaguchi, M; Otake, Y; Shimizu, HM

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 76 巻 ( 6 ) 頁： 064008 - 064008 2007年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：一般社団法人日本物理学会

We have revealed the criterion to observe moiré fringes in a neutron spin interferometry. In former studies using wave front division, neutron beam had to be collimated by fine slits. On the other hand, we have succeeded to observe moiré fringes with divergence angle of 8.3 mrad using spin polarization division. A model based on partial coherence theory has been developed and verified experimentally. These results will be the basis for neutron wave front manipulation technique using magnetic birefringence. ©2007 The Physical Society of Japan.

DOI： 10.1143/JPSJ.76.064008

Low energy particle detector using a superconducting transition edge sensor 査読有り

Ohno, M; Sato, H; Mishima, K; Ikeda, T; Shimizu, HM

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY 17 巻 ( 2 ) 頁： 328 - 331 2007年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEEE Transactions on Applied Superconductivity

Precise measurement of neutron beta decay tests predictions of the Standard Model of electroweak interaction. The co-efficient a of the antineutrino/electron angular correlation is determined by measuring the energy spectrum of the recoil protons generated in the neutron beta decay. A proton spectrometer required for this measurement demands high detection efficiency, high energy resolution and a large detection area. We have begun development of a Transition Edge Sensor (TES) microcalorimeter for use as a low energy particle detector. To realize the large detection area we have designed a pixelated TES array incorporating a parallel biasing scheme. Our TES device consists of 4-pixels using a Au/Ti/Au trilayer film adjusted to a superconducting transition temperature of Tc ∼ 380 mK. This temperature is convenient for use in a 3He cryostat with a pulse tube refrigerator. The Au films improve thermal conductivity, thereby reducing position dependent effects and allow an increased detector area. © 2007 IEEE.

DOI： 10.1109/TASC.2007.898057

Wide-<i>q</i> observation from 10<SUP>-4</SUP> to 2.0 A<SUP>-1</SUP> using a focusing and polarized neutron small-angle scattering spectrometer, SANS-J-II 査読有り Open Access

Iwase, H; Koizumi, S; Suzuki, JI; Oku, T; Sasao, H; Tanaka, H; Shimizu, HM; Hashimoto, T

JOURNAL OF APPLIED CRYSTALLOGRAPHY 40 巻 ( SUPPL. 1 ) 頁： S414 - S417 2007年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Applied Crystallography

In order to extend an upper q-limit [q is the magnitude of the scattering vector q, defined by q = (4π/λ)sinθ, where λ and 2θ are the wavelength and the scattering angle, respectively], high-angle <sup>3</sup>He sub-detectors were installed on a focusing and polarized neutron small-angle scattering spectrometer (SANS-J-II) at JRR-3, Tokai, Japan. Consequently, the upper q-limit was improved from 0.2 to 2.0 Å<sup>-1</sup>. To quantitatively discriminate spin incoherent scattering from hydrogen or to perform nuclear spin polarization contrast variation, a remanent supermirror analyser is also available on the high-angle sub-detector. By combining a focusing ultra-small-angle scattering, realised by compound and/or magnetic lens and high-resolution area detector, SANS-J-II is able to cover from 3 × 10<sup>-4</sup> to 2.0 Å<sup>-1</sup> (four orders of magnitude of q), which benefits investigation of hierarchically ordered systems, found widely in hard, soft and bio-materials. © International Union of Crystallography 2007.

DOI： 10.1107/S0021889807006280

Focusing and polarized neutron small-angle scattering spectrometer (SANS-J-II). The challenge of observation over length scales from an angstrorm to a micrometre 査読有り Open Access

Koizumi, S; Iwase, H; Suzuki, JI; Oku, T; Motokawa, R; Sasao, H; Tanaka, H; Yamaguchi, D; Shimizu, HM; Hashimoto, T

JOURNAL OF APPLIED CRYSTALLOGRAPHY 40 巻 ( SUPPL. 1 ) 頁： S474 - S479 2007年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Applied Crystallography

SANS-J (a pinhole small-angle neutron scattering spectrometer at research reactor JRR3, Tokai, Japan) was reconstructed as a focusing and polarized neutron small-angle scattering spectrometer (SANS-J-II). By employing focusing lenses of a biconcave MgF<inf>2</inf> crystal or of a sextupole permanent magnet and a high-resolution photomultiplier, the minimum accessible magnitude of the scattering vector q min was improved from 3 × 10<sup>-3</sup> Å<sup>-1</sup> to an ultra-small-angle scattering (USAS) of 3 × 10<sup>-4</sup> Å<sup>-1</sup>. Compared with a Bonse-Hart double-crystal method, the advantages of focusing USAS are the efficient detection of anisotropic USAS with an area detector, an improvement in q resolution Δq/q at conventional magnitudes of the scattering vector q ∼ 10 <sup>-3</sup> Å<sup>-1</sup> and a gain in neutron flux in the conventional q region of q ∼ 10<sup>-3</sup> Å<sup>-1</sup>. © International Union of Crystallography 2007.

DOI： 10.1107/S0021889807014392

A focusing-geometry small-angle neutron scattering instrument with a magnetic neutron lens 査読有り Open Access

Oku, T; Iwase, H; Shinohara, T; Yamada, S; Hirota, K; Koizumi, S; Suzuki, JI; Hashimoto, T; Shimizu, HM

JOURNAL OF APPLIED CRYSTALLOGRAPHY 40 巻 ( SUPPL. 1 ) 頁： S408 - S413 2007年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Applied Crystallography

We have constructed a focusing-geometry small-angle neutron scattering (FSANS) instrument, SANS-J-II, with two kinds of neutron focusing device: a series of compound refractive lenses made of MgF<inf>2</inf> and a magnetic neutron lens based on an extended Halbach-type sextupole magnet. In this study, we investigated the performance of the FSANS instrument with the magnetic neutron lens. The intensity distribution of a direct neutron beam focused on the detector plane by the magnetic neutron lens had a ratio of the peak height to the background level of ∼6 × 10<sup>4</sup> for a polarized neutron beam with a polarization degree of ∼0.99. It is found that a minimum value of the measurable q range [where q is the modulus of the scattering vector and is defined as q = (4π/λ)sin(θ/2), where θ is the scattering angle and λ is the neutron wavelength], q<inf>min</inf>, of 6.5 × 10<sup>-4</sup> Å<sup>-1</sup> can be achieved by the FSANS instrument with the magnetic neutron lens using neutrons with λ = 6.6 Å and Δλ/λ = 0.13 for the full width at half maximum. © International Union of Crystallography 2007.

DOI： 10.1107/S0021889807003822

X-ray detection using superconducting tunnel junction shaped normal-distribution-function 査読有り

Taino, T; Nishihara, T; Hoshino, K; Myoren, H; Sato, H; Shimizu, HM; Takada, S

IEICE TRANSACTIONS ON ELECTRONICS E90C 巻 ( 3 ) 頁： 566 - 569 2007年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：IEICE Transactions on Electronics

A normal-distribution-function-shaped superconducting tunnel junction (NDF-STJ) which consists of Nb/Al-AlO<inf>x</inf>/Al/Nb has been fabricated as an X-ray detector. Current - voltage characteristics were measured at 0.4 K using three kinds of STJs, which have the dispersion parameters σ of 0.25, 0.45 and 0.75. These STJs showed very low subgap leakage current of about 5 nA. By irradiating with 5.9 keV X-rays, we obtained the spectrum of these NDF-STJs. They showed good energy resolution with small magnetic fields of below 3 mT, which is about one-tenth of those for conventional-shaped STJs. Copyright © 2007 The Institute of Electronics, Information and Communication Engineers.

DOI： 10.1093/ietele/e90-c.3.566

多チャンネル検出器システムへ向けたアナログーデジタル変換器の開発

山崎拓朗, 宮嶋茂之, 佐藤広海, 清水裕彦, 藤巻朗

電子情報通信学会技術研究報告. SCE, 超伝導エレクトロニクス 106 巻 ( 503 ) 頁： 7 - 12 2007年1月

出版者・発行元：一般社団法人電子情報通信学会

超伝導トンネル接合素子(以下STJ: Superconducting Tunnel Junction)は半導体検出器に比べてエネルギー分解能が一桁以上高く、非常に精度のよい検出ができる。その反面、面積を大きくすることができず有感領域が小さいといった問題がある。そこで我々はSTJの実効的有感面積を拡大させるために、STJ、アナログ-デジタル(AD)変換器、単一磁束量子(SFQ)信号処理回路を用いて構築できる多チャンネル検出器システムを考案した。このシステムの実現のための最初のステップとして超伝導AD変換器とSTJ検出器との統合を試みた。STJの動作状況はチャンバー内にSFQ回路の障害となり得る磁場を発生させるなど必ずしもSFQ回路の動作環境として相応しくない。我々はこの問題に対して磁気シールドなどの対策を施しSTJ用クライオスタット内での超伝導AD変換器の正常動作を確認した。

Small-angle neutron scattering (SANS) and dynamic light scattering (DLS) analyses of the initial aggregation process of tau by oxidative stress 査読有り

Sachio Naito, Susumu Ikeda, Hirohiko Shimizu, Hideki Mochizuki, Toru Yasuda, Yoshikuni Mizuno, Michihiro Furusaka, Satoru Fujiwara, Junichi Suzuki, keiji Wada

NEUROSCIENCE RESEARCH 58 巻頁： S176 - S176 2007年

超伝導検出器アレイを用いたテラヘルツイメージング

有吉誠一郎, 大谷知行, ドブロユアドリアン, 松尾宏, 佐藤広海, 田井野徹, 川瀬晃道, 清水裕彦

電子情報通信学会技術研究報告. ED, 電子デバイス 106 巻 ( 403 ) 頁： 59 - 63 2006年12月

出版者・発行元：一般社団法人電子情報通信学会

電波と光波の境界領域に位置するテラヘルツ波は、物質に対する透過性と吸収スペクトルを利用した物質同定性を併せ持つなど、他の波長帯では見られない特長を有し、産業分野の製造ラインなどでの非破壊透視検査、薬品検査や癌診断などの医薬分野応用、天文観測研究など、様々な分野での応用が期待されている。しかし、このバンドで超高感度かつ短時間イメージングを行うために必要な多素子検出技術は未開拓である。そこで我々は、超伝導トンネル接合素子(STJ)を用いた超高感度テラヘルツ光検出器とそのイメージングアレイ化に向けた研究開発を行っている。検出器1画素の膜構造は、ニオブ超伝導体の平面アンテナと超伝導マイクロストリップラインをSTJ素子で橋渡ししており、光子誘起トンネル現象を検出原理とする。本稿では、STJ検出器の概要とリニアアレイを用いたイメージング試験結果とともに、その将来性について述べる。

THz波検出用基板吸収型超伝導トンネル接合素子

田井野徹, 石井宏和, 吉村正太, 明連広昭, 高田進, 大谷知行, 有吉誠一郎, 佐藤広海, 清水裕彦, 川瀬晃道

電子情報通信学会技術研究報告. ED, 電子デバイス 106 巻 ( 403 ) 頁： 53 - 57 2006年12月

出版者・発行元：一般社団法人電子情報通信学会

近年テラヘルツ波は工学、医学、理学など様々な分野で注目を集めている。我々はテラヘルツ波の新たな検出器として、超伝導トンネル接合素子(STJ)に着目し、その検出器開発を行っている。我々の提案する検出器は、STJ直下に存在する基板に対してテラヘルツ波を照射して、基板内で発生するフォノンを利用する"基板吸収型STJ"である。本論文では、基板吸収型STJを用いたテラヘルツ波検出のこれまでの実験について報告する。

Thermal neutron refraction by material prism 査読有り

Shinohara, T; Hirota, K; Adachi, T; Ikeda, K; Shimizu, HM; Suzuki, JI; Oku, T

PHYSICA B-CONDENSED MATTER 385-86 巻頁： 1232 - 1235 2006年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Physica B Condensed Matter

Neutron refractive optics is a powerful tool for beam focusing due to its large effective aperture compared to reflective optics. Because neutron refraction angle decreases with shorter wavelengths, the application of refractive optics has been restricted to the cold neutron range. To expand the applicable wavelength range, we have developed a new refractive optics using an amorphous perfluoropolymer. This refractive optics is composed of several hundred thin sheets, each of which has a large number of grooves on the top surface. The refraction experiment was performed at the H-8 beam port of KENS, and it was confirmed that the thermal neutron beam can be refracted using this material prism. © 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.05.418

　前のページ - 次のページ　

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30