研究者詳細 - 北口　雅暁

論文 - 北口　雅暁

分割表示 186 件中 141 - 160 件目／全件表示 >>

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

Kaoru Taketani, Kenji Mishima, Takashi Ino, Tamaki Yoshioka, Suguru Muto, Takahiro Morishima, Hirohiko M. Shimizu, Takayuki Oku, Junichi Suzuki, Takenao Shinohara, Kenji Sakai, Hiromi Sato, Katsuya Hirota, Yoshie Otake, Masaaki Kitaguchi, Masahiro Hino, Yoshichika Seki, Yoshihisa Iwashita, Masako Yamada, Masahiro Ichikawa, Takanori Sugimoto, Shinsuke Kawasaki, Sachio Komamiya, Yoshio Kamiya, Hidetoshi Otono, Satoru Yamashita, Peter Geltenbort

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）

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

Web of Science

Scopus

A beam divergence correction mirror for neutron resonance spin echo 査読有り国際誌

R. Maruyama, M. Hino, H. Hayashida, M. Kitaguchi, N. Achiwa, D. Yamazaki, T. Ebisawa, K. Soyama

Physica B: Condensed Matter 404 巻 ( 17 ) 頁： 2594 - 2599 2009年9月

Development of neutron resonance spin flipper for high resolution spin echo spectrometer 査読有り国際誌

Kitaguchi M, Hino M, Kawabata Y, Tasaki S, Hayashida H, Maruyama R, Ebisawa T

Physica B: Condensed Matter 404 巻 ( 17 ) 頁： 2590 - 2593 2009年9月

A new MIEZE technique for investigating relaxation of magnetic nanoparticles 査読有り

Hirotoshi Hayashida, Masahiro Hino, Masaaki Kitaguchi, Norio Achiwa, Yuji Kawabata

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 600 巻 ( 1 ) 頁： 56 - 59 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：ELSEVIER SCIENCE BV

There is no reduction in the contrast of a modulated intensity of zero effort (MIEZE) signal even when magnetic scattering occurs, whereas the contrasts of neutron spin echo and neutron resonance spin echo are reduced by more than a factor of two. However, since MIEZE measures both the intensities of quasielastic nuclear and magnetic scatterings, it is generally not easy to use a conventional MIEZE setup to simultaneously separate magnetic and nonmagnetic fluctuations of magnetic nanoscale particles. We propose a new MIEZE technique, which involves inserting a second analyzer and an additional pi-flipper that is able to distinguish between the magnetic and nonmagnetic quasielastic scattering intensities. We succeeded in observing superparamagnetic fluctuations of magnetite particles in a ferrofluid by using this new technique. (C) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nima.2008.11.101

Web of Science

Shield evaluation of cold neutron curved guide tubes for J-PARC neutron resonance spin echo spectrometers 査読有り

Toru Ebisawa, Kazuhiko Soyama, Dai Yamazaki, Ryuji Maruyama, Seiji Tasaki, Yutaka Abe, Hiroyuki Hayashida, Masahiro Hino, Masaaki Kitaguchi, Yuji Kawabata, Koji Niita

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 600 巻 ( 1 ) 頁： 126 - 128 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：ELSEVIER SCIENCE BV

it is planned that three neutron resonance spin echo spectrometers will be installed in the No. 17 beam port of JSNS. In order to install these three spectrometers in one beam port, the neutron incident beam system to be installed in No. 17 port cannot only supply three polarized neutron beams to these spectrometers, but should also create very low background levels of neutron and gamma rays in the experimental area. We report based on shield evaluations how to realize the low background level by using two highly curved neutron guide tubes with high quality supermirrors. (C) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nima.2008.11.090

Web of Science

Development of devices for beam divergence correction in the high-resolution NRSE spectrometer 査読有り

Masaaki Kitaguchi, Masahiro Hino, Yuji Kawabata, Hirotoshi Hayashida, Seiji Tasaki, Ryuji Maruyama, Toru Ebisawa

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 600 巻 ( 1 ) 頁： 117 - 119 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：ELSEVIER SCIENCE BV

Correction for beam divergence effect in the neutron resonance spin echo (NRSE) spectrometer will be discussed. The new type of devices called "coupling coils" is proposed to change the spin quantization axis for the correction. The feasibility of correction for the vertical divergence has been demonstrated by numerical calculations and Monte-Carlo simulations. (C) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nima.2008.11.072

Web of Science

A study on reflectivity limit of neutron supermirror 査読有り

Masahiro Hino, Masaaki Kitaguchi, Hirotoshi Hayashida, Seiji Tasaki, Toru Ebisawa, Ryuji Maruyama, Norio Achiwa, Yuji Kawabata

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 600 巻 ( 1 ) 頁： 207 - 209 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：ELSEVIER SCIENCE BV

We have fabricated m=2.9 NiC/Ti supermirror on a silicon wafer in which surface roughness is about 0.4 nm by ion beam sputtering technique. The reflectivity of supermirror at m=2.8 and 2.9 were 0.94 and 0.90, respectively. The reflectivity, of 0.94 at m=2.8 is in the vicinity of theoretical limit including the effects of absorption and incoherent scattering. We show the experimental results and theoretical expectation based on a simple Debye-Waller roughness model, and discuss realistic reflectivity limit of supermirror deposited on the ordinary silicon substrate. (c) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.nima.2008.11.125

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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

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

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

Nucl. Instr. and Methods in Phys. Res. A 600 巻頁： 342 - 345 2009年

A study of resolution function on a MIEZE spectrometer 査読有り国際誌

H. Hayashida, M. Hino, M. Kitaguchi, Y. Kawabata, N. Achiwa

Measurement Science and Technology 19 巻 ( 3 ) 2008年3月

記述言語：英語掲載種別：研究論文（学術雑誌）

We have installed a MIEZE (modulated intensity by zero effort) spectrometer in the C3-1-2-2(MINE1) port at JRR-3M. In the MIEZE spectrometer, a sample is placed after the analyzer. Thus the contrast of the MIEZE signal can be observed without reduction even in the case of magnetic scattering where the signal for NSE (neutron spin echo) and NRSE (neutron resonance spin echo) instruments is less than half. The MIEZE signal is sensitive to the dispersion of neutron trajectories from the sample to the detector. In other words, the MIEZE signal is reduced only due to the dispersion even without in- and quasi-elastic scattering. We studied the correlation between experimental configuration and its resolution function using the Monte Carlo simulation. We prepared a magnetite ferrofluid sample with a typical particle diameter of 84 , and examined the simulation model by experiments. © 2008 IOP Publishing Ltd.

DOI： 10.1088/0957-0233/19/3/034006

Scopus

Correction for beam divergence effect in a NRSE spectrometer with high resolution 査読有り国際誌

Kitaguchi M, Hino M, Kawabata Y, Hayashida H, Tasaki S, Maruyama R, Ebisawa T

Measurement Science and Technology 19 巻 ( 3 ) 頁： 034014 2008年1月

Partial decay widths of the φ into e+e- and K+K- pairs in 12 GeV p + a reactions at KEK-PS E325 査読有り

F. Sakuma, J. Chiba, H. En'yo, Y. Fukao, H. Funahashi, H. Hamagaki, M. Ieiri, M. Ishino, H. Kanda, M. Kitaguchi, S. Mihara, K. Miwa, T. Miyashita, T. Murakami, R. Muto, T. Nakura, M. Naruki, K. Ozawa, O. Sasaki, M. Sekimoto, T. Tabaru, K.H. Tanaka, M. Togawa, S. Yamada, S. Yokkaichi, Y. Yoshimura

Modern Physics Letters A 23 巻 ( 27-30 ) 頁： 2401 - 2404 2008年

Observation of MIEZE signal with an effective frequency of 1 MHz 査読有り

Hirotoshi Hayashida, Masaaki Kitaguchi, Masahiro Hino, Yuji Kawabata, Toru Ebisawa

PHYSICA B-CONDENSED MATTER 397 巻 ( 1-2 ) 頁： 144 - 146 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：ELSEVIER SCIENCE BV

We developed a modulated intensity of zero effort (MIEZE) spectrometer with an effective frequency of I MHz. Three resonance spin flippers (RSFs) and two-dimentional position sensitive detector (2D-PSD) were used for the MIEZE spectrometer. The frequency of RSFs was 0.5 MHz and 2D-PSD works in TOF mode with 100 ns. The incident neutron wavelength was 0.81 nm and the distance between sample position and detector position was 0.5 in. The Fourier time was estimated to be 1.7 ns. The contrast of the I MHz echo signal was 0.4. (c) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2007.02.087

Web of Science

Moire fringes in a neutron spin interferometer 査読有り

Kaoru Taketani, Yoshichika Seki, Haruhiko Funahashi, Masahiro Hino, Masaaki Kitaguchi, Yoshic Otake, Hirohiko M. Shimizu

JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 76 巻 ( 6 ) 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：PHYSICAL SOC JAPAN

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.

DOI： 10.1143/JPSJ.76.064008

Web of Science

Development of a resonance spin flipper for NRSE/MIEZE on a pulsed neutron beam with an oscillating frequency of 500kHz 査読有り国際誌

Hirotoshi Hayashida, Masaaki Kitaguchi, Masahiro Hino, Yuji Kawabata, Ryuji Maruyama, Toru Ebisawa

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 574 巻 ( 2 ) 頁： 292 - 296 2007年5月

Nuclear-matter modification of decay widths in the phi -> e(+)e(-) and phi -> K+K- channels 査読有り

F. Sakuma, J. Chiba, H. En'yo, Y. Fukao, H. Funahashi, H. Hamagaki, M. Ieiri, M. Ishino, H. Kanda, M. Kitaguchi, S. Mihara, K. Miwa, T. Miyashita, T. Murakami, R. Muto, T. Nakura, M. Naruki, K. Ozawa, O. Sasaki, M. Sekimoto, T. Tabaru, K. H. Tanaka, M. Togawa, S. Yamada, S. Yokkaichi, Y. Yoshimura

PHYSICAL REVIEW LETTERS 98 巻 ( 15 ) 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：AMER PHYSICAL SOC

The invariant mass spectra of phi -> K+ K- are measured in 12 GeV p + A reactions in order to search for the in-medium modification of phi mesons. The observed K+ K- spectra are well reproduced by the relativistic Breit-Wigner function with a combinatorial background shape in three beta gamma regions between 1.0 and 3.5. The nuclear mass number dependence of the yields of the K+ K- decay channel is compared to the simultaneously measured e(+) e(-) decay channel for carbon and copper targets. We parameterize the production yields as sigma(A) = sigma(0)A(alpha) and obtain alpha(phi -> K+K-) - alpha(phi -> e+e-) to be 0: 14 +/- 0: 12. Limits are obtained for the partial decay widths of the phi mesons in nuclear matter.

DOI： 10.1103/PhysRevLett.98.152302

Web of Science

Evidence for in-medium modification of the meson at normal nuclear density 査読有り国際誌

R. Muto, J. Chiba, H. En'Yo, Y. Fukao, H. Funahashi, H. Hamagaki, M. Ieiri, M. Ishino, H. Kanda, M. Kitaguchi, S. Mihara, K. Miwa, T. Miyashita, T. Murakami, T. Nakura, M. Naruki, K. Ozawa, F. Sakuma, O. Sasaki, M. Sekimoto, T. Tabaru, K.H. Tanaka, M. Togawa, S. Yamada, S. Yokkaichi, Y. Yoshimura

Physical Review Letters 98 巻 ( 4 ) 2007年

Medium modification of vector mesons observed in 12 GeV p+A reactions 査読有り

M. Naruki, H. En'Yo, R. Muto, T. Tabaru, S. Yokkaichi, Y. Fukao, H. Funahashi, M. Ishino, H. Kanda, M. Kitaguchi, S. Mihara, K. Miwa, T. Miyashita, T. Murakami, T. Nakura, F. Sakuma, M. Togawa, S. Yamada, Y. Yoshimura, J. Chiba, M. Ieiri, O. Sasaki, M. Sekimoto, K.H. Tanaka, H. Hamagaki, K. Ozawa

Journal of Physics G: Nuclear and Particle Physics 34 巻 ( 8 ) 頁： S1059-S1063 2007年

Study of in-medium meson modification in 12 GeV p + A reactions 査読有り

S. Yokkaichi, H. En'yo, M. Naruki, R. Muto, T. Tabaru, J. Chiba, M. Ieiri, M. Sekimoto, O. Sasaki, K.H. Tanaka, H. Funahashi, Y. Fukao, M. Kitaguchi, M. Ishino, H. Kanda, S. Mihara, T. Miyashita, K. Miwa, T. Murakami, T. Nakura, F. Sakuma, M. Togawa, S. Yamada, Y. Yoshimura, H. Hamagaki, K. Ozawa

International Journal of Modern Physics A 22 巻 ( 2-3 ) 頁： 397 - 405 2007年

A test of MIEZE-reflectometer for study of surface and interface 査読有り

Masahiro Hino, Masaaki Kitaguchi, Hirotoshi Hayashida, Yuji Kawabata, Seiji Tasaki, Toru Ebisawa, Dai Yamazaki, Ryuji Maruyama, Keiji Tanaka, Naoya Torikai, Rintaro Inoue, Toshiji Kanaya

PHYSICA B-CONDENSED MATTER 385-86 巻頁： 1125 - 1127 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：ELSEVIER SCIENCE BV

We have installed a MIEZE-type spin echo spectrometer at the C3-1-2-2 (MINE1) port at the JRR-3 M in the Japan Atomic Energy Agency. By combining neutron reflectometry and the MIEZE, it is possible to detect inelastic and quasi-elastic scattering on the surface and at the interface. We have succeeded in measuring a MIEZE signal for which the Fourier time is up to 0.8 us. Though the Fourier time is small, we tested several samples by the MIEZE reflectometer. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.physb.2006.05.388

Web of Science

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