Journal of Neutron Research - Volume 13, issue 1-3

Authors: Arai, Masatoshi | Torikai, Naoya

Article Type: Research Article

DOI: 10.1080/10238160412331297746

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 1-5, 2005

Authors: Nagamiya, Shoji

Article Type: Research Article

Abstract: From Japanese fiscal year JFY01, which started on April 1, 2001, a new accelerator project to provide high-intensity proton beams proceeded into its construction phase. This project, which is now called the Japan Proton Accelerator Research Complex (J-PARC) project, is in progress under a cooperation of two institutions, High Energy Accelerator Research Organization (KEK) and Japan Atomic Energy Research Institution (JAERI). We set a goal to achieve 1 MW proton beams at 3 GeV and 0.75 MW beams at 50 GeV. The construction period is seven years, with anticipated first beams in the spring of 2008. In this article, I …will describe the project itself and the present status of the project. Show more

Keywords: High-intensity proton accelerator, Pulse neutron source, Nuclear transmutation, Proton synchroton

DOI: 10.1080/10238160412331299537

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 7-10, 2005

Authors: Zhang, J. | Yan, Q.W. | Zhang, C. | Zhang, P.L. | Fu, S.N. | Wang, F.W. | Zhang, Z. | Fang, S.X.

Article Type: Research Article

Abstract: We report on the recent progress of the project of the Chinese Spallation Neutron Source. The preliminary conceptual designs of the accelerator complex, the target system and the neutron scattering instruments are included.

Keywords: CSNS project, Conceptual design, Accelerator, Target station, Neutron spectrometers

DOI: 10.1080/10238160412331297755

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 11-14, 2005

Authors: Loong, C.-K. | Koyanaka, H.

Article Type: Research Article

Abstract: Understanding material properties at a fundamental level is important to the development of the full potential of substances and the fruition of eventual industrial and commercial applications. The techniques of neutron-scattering provide unique capabilities in characterization of materials at nanometer scale thereby benefiting industrial research. We focus on a recent study of lithium extraction and arsenic removal from natural waters using nanostructured manganese-oxide based adsorbents. Neutron diffraction and spectroscopy, when combining with other characterization techniques and theoretical modeling, contributed to the understanding of the relation between adsorption behavior and material properties.

Keywords: Neutron scattering, Manganese oxide adsorbent, Lithium extraction, Arsenic removal

DOI: 10.1080/10238160412331297773

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 15-19, 2005

Authors: Kagi, H. | Nagai, T. | Komatsu, K. | Okada, T. | Wada, C. | Loveday, J.S. | Parise, J.B.

Article Type: Research Article

Abstract: Pressure responses of hydrogen bonding interactions were compared between potassium hydrogen carbonate (KHCO3 ) and sodium hydrogen carbonate (NaHCO3 ). KHCO3 undergoes a pressure-induced structural change at 2.8 GPa and room temperature whereas no phase transition has been found so far for NaHCO3 up to 11 GPa. KHCO3 exhibits a substantial decrease in the O—H···O angle with increasing pressure. This change could be a trigger for the phase transition at 2.8 GPa. By contrast, no significant change in O—H···O angle was observed for NaHCO3 up to 7 GPa. Based on the observations using neutron diffraction, X-ray …diffraction and vibrational spectroscopy at high pressure, a possible mechanism for the phase transition of KHCO3 is suggested. In addition, the phase boundary of KHCO3 caused by the pressure-induced transition was determined using in situ Raman spectroscopy at high pressure. Show more

Keywords: Hydrogen bond, High pressure, Neutron diffraction, Phase transition, Hydrogen carbonate, Earth science

DOI: 10.1080/10238160412331297782

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 21-26, 2005

Authors: Lehmann, Eberhard H. | Vontobel, P. | Frei, G.

Article Type: Research Article

Abstract: This article describes the status of neutron imaging with the focus on the detection systems in use, mainly based on a digital approach. When intense pulsed will be available in the near future, neutron imaging can take profit too by applying energy selective and triggered “flash” methods for dedicated investigations. Therefore, the layout, specifications and options should be discussed now in order to have the right beam line available at one or some of the pulsed sources.

Keywords: Neutron imaging, Digital methods, Hydrogen detection, Time-of-flight methods, Bragg edges

DOI: 10.1080/10238160412331297791

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 27-31, 2005

Authors: Käppeler, F.

Article Type: Research Article

Abstract: The abundance of elements between Fe and the actinides have essentially all been produced by neutron reactions, either by the slow neutron capture process during helium burning in red giant stars (s process) or by explosive nucleosynthesis, e.g. in supernovae (r and p process). Laboratory studies have so far concentrated on the s process, which operates in or near the valley of β-stability. Under these conditions laboratory results are of direct impact for the interpretation of the observed abundance patterns and their role as crucial tests for stellar evolution models. The high flux at spallation neutron sources allows one to …investigate numerous difficult and hitherto inaccessible cases, including the cross sections of important radioactive nuclei. Show more

Keywords: Neutron capture process, Nucleosynthesis of heavy elements, Stellar (n,γ) rates, Spallation neutron sources

DOI: 10.1080/10238160412331299546

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 33-38, 2005

Authors: Gudkov, Vladimir

Article Type: Research Article

Abstract: New generation of neutron decay experiments, which can be done with high accuracy at new Spallation Neutron Sources, are very important for solution of current problems of fundamental physics and for tests of the Standard Model. The open problems of theory related to these experiments and possible approaches to their solutions are discussed.

Keywords: Neutron, β-Decay, Radiative corrections, Standard model

DOI: 10.1080/10238160412331297809

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 39-43, 2005

Authors: Kawano-Furukawa, H. | Urata, M. | Nagata, T. | Yoshizawa, H. | Kadowaki, H. | Dai, P.

Article Type: Research Article

Abstract: In this paper, we present the results of our unpolarized inelastic neutron scattering experiments on the spin-triplet superconductor Sr2 RuO4 . Our measurements showed that incommensurate spin susceptibilities at q0 = (0.3 0.3 0) exhibit c-axis anisotropy. This discovery supports the notion that magnetic anisotropy may induce p-wave superconductivity in this material.

Keywords: Spin-triplet superconductor, Incommensurate spin fluctuations, Spin anisotropy, Superconducting mechanism

DOI: 10.1080/10238160412331297818

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 45-48, 2005

Authors: Tanaka, I. | Ozeki, T. | Ohhara, T. | Kurihara, K. | Niimura, N.

Article Type: Research Article

Abstract: Japan proton accelerator research complex (J-PARC) with the power of 1 MW have been constructing since 2001 in JAERI, Japan. And the first beam will come by 2007. As one important day-one neutron instruments at Material and Life Science Facility in J-PARC, a single crystal diffractometer No.1 for structural analysis of biological macromolecules and organic compounds with unit cell dimensions less than about 135 Å (BIX-P1) has been proposed, considering the international competition in biological science and the expansion of the application to the industrial fields. It is expected to gain efficiency more than 50 times larger than neutron biological …diffractometers BIX-3 and BIX-4 installed at JRR-3 reactor also in JAERI. In this paper, evaluation of moderator, items of necessary R & D and the current specification of BIX-P1 are shown. Show more

Keywords: TOF neutron diffractometer, Biological macromolecular crystallography, Conceptional design of BIX-P1, Coupled moderator, High resolution 2-dimensional detector, Data reduction software

DOI: 10.1080/10238160412331297827

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 49-54, 2005

Authors: Ishigaki, T. | Kamiyama, T. | Oikawa, K.

Article Type: Research Article

Abstract: In the J-PARC project, we are proposing two powder diffractometers. This article describes these powder diffractometers: a versatile diffractometer with resolution of Δd/d ≈ 0.1% for materials science and a high- resolution diffractometer with Δd/d ≈ 0.03% for precise analysis. Each of them looks at the other side of an off- centered decoupled hydrogen poisoned moderator. Another type of high intensity powder diffractometer is also proposed separately as a total scattering instrument.

Keywords: Powder diffractometer, Materials science, High-precision analysis, High-resolution

DOI: 10.1080/10238160412331297836

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 55-58, 2005

Authors: Itoh, S. | Ohoyama, K. | Otomo, T. | Nakajima, K. | Kuwahara, K. | Kajimoto, R. | Kamiyama, T. | Yamamuro, O.

Article Type: Research Article

Abstract: A designed performance of the high resolution chopper spectrometer of which construction has been proposed at J-PARC to study dynamical properties of materials showing a wide spatial and temporal correlations is summarized.

Keywords: Chopper spectrometer, Pulsed neutron source, Inelastic neutron scattering, Fermi chopper

DOI: 10.1080/10238160412331297845

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 59-62, 2005

Authors: Monkenbusch, M. | Ohl, M. | Richter, D. | Pappas, C. | Zsigmond, G. | Lieutenant, K. | Mezei, F.

Article Type: Research Article

Abstract: Measures to optimally operate a neutron spin-echo (NSE) spectrometer at a pulsed source are discussed. Gain factors and resolution functions are addressed.

Keywords: Neutron spin-echo, Pulsed source, Spallation neutron source, Fourier time

DOI: 10.1080/10238160412331299555

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 63-66, 2005

Authors: Bau, Robert

Article Type: Research Article

Abstract: This article is a short review of the results of single crystal neutron diffraction studies on proteins, and is meant to serve two purposes: firstly, as a brief update of new results which appeared since our last review in 2002, [Tsyba, I. and Bau, R. (2002) “Neutron Diffraction Studies on Proteins”, Chemtracts 15, 233] and secondly to focus on one particular area: cases in which neutron diffraction studies have helped in the understanding of the catalytic activity of enzymes.

Keywords: Neutron diffraction, Proteins, Crystallography, Structure, Single-crystal

DOI: 10.1080/10238160412331297854

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 67-77, 2005

Authors: Middendorf, H.D.

Article Type: Research Article

Abstract: The third-generation neutron facilities under construction at Tokai (JSNS) and at Oak Ridge (SNS) will provide opportunities for strengthening and expanding research on biomolecular dynamics. Following an outline of current trends in biomolecular applications of quasielastic (QENS) and inelastic (INS) neutron scattering, this paper discusses likely directions of future work on proteins and identifies challenging problem areas.

Keywords: Neutron spectroscopy, Protein dynamics, Hydration, Photosensitive proteins

DOI: 10.1080/10238160412331299564

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 79-85, 2005

Authors: Inaba, A. | Sakisato, N. | Bickerstaffe, A.K. | Clarke, S.M.

Article Type: Research Article

Abstract: There is a continuing interest in “2D solids” which appear at various interfaces for their novel structure and dynamics. Many simple molecules are adsorbed on solid surfaces, such as graphite, to form 2D layers that are solid at low temperatures. Interestingly, similar solid monolayers are formed at the interface between bulk liquid adsorbates and graphite. In this work, we report a 2D-like ice structure which appears in the initial stage of crystallisation of aqueous solutions from the undercooled state. We present results obtained by neutron scattering to demonstrate the formation of this novel structure and its temperature evolution.

Keywords: Monolayer, Ice, Diffraction, Crystallisation

DOI: 10.1080/10238160412331297863

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 87-90, 2005

Authors: Misawa, M. | Dairoku, I. | Honma, A. | Yamada, Y. | Sato, T. | Maruyama, K. | Mori, K. | Suzuki, S. | Otomo, T.

Article Type: Research Article

Abstract: Absolute intensity of small angle neutron scattering (SANS) has been measured for 1-propanol aqueous solution. Fractal dimension evaluated from the observed intensity depends on 1-propanol content in a peculiar way. Mesoscale structure of the solution has been visualized by means of large-scale reverse Monte Carlo (RMC) technique. It is suggested that most molecules are located on surface of clusters and cluster-size distribution obeys a simple power law.

Keywords: Neutron small angle scattering, Aqueous solution, Mesoscale structure, Fractal dimension, Reverse Monte Carlo analysis, Structure visualization

DOI: 10.1080/10238160412331297872

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 91-95, 2005

Authors: Kamiyama, T. | Noda, H. | Ito, J. | Iwasa, H. | Kiyanagi, Y. | Ikeda, S.

Article Type: Research Article

Abstract: We applied the method of neutron resonance absorption spectroscopy to thermometric measurements of a bulk object. Through an analysis of the resonance absorption spectrum of imbedded neutron-absorbing nuclides, the “effective temperature”, which coincides with the actual local temperature near and above room temperature, can be determined. If a thermal gradient exists, computed tomography techniques could be used in conjunction with the analysis for a reconstruction of the temperature distribution over a planar cross-sectional area. We find that the experimental data agree with the temperature profile calculated from the heat conduction equations. The measurements were carried out using the neutron resonance …absorption spectrometer DOG of KENS, Japan. The overall results demonstrated the feasibility of this method for industrial applications where remote-sensing and non-destructive temperature mapping of bulk objects is necessary. Show more

Keywords: Neutron resonance absorption, Thermometry, Computer tomograph, Non-destructive analysis

DOI: 10.1080/10238160412331297881

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 97-101, 2005

Authors: Ebisawa, T. | Soyama, K. | Yamazaki, D. | Tasaki, S. | Sakai, K. | Oku, T. | Maruyama, R. | Hino, M.

Article Type: Research Article

Abstract: We have proposed multi-stage spin flip chopper system to realize very high S/N ratio. Very high S/N ratios of about 3000 and 105 have been demonstrated for double and triple spin flip chopper systems, respectively. We here describe a double neutron spin flip chopper system applicable to pulsed source using polarizing bent guide tubes instead of simple magenetic mirrors, in order to obtain a high intensity and high S/N ratio. Simulation results show that it will realize spin flip chopper of high neutron intensity and S/N ratios.

Keywords: Neutron spin flip chopper, Polarizing bent guide tube, Pulsed flipper, Pulsed neutron source

DOI: 10.1080/02781070412331298822

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 103-106, 2005

Authors: Tasaki, Seiji | Kawabata, Yuji | Hino, Masahiro | Maruyama, Ryuji | Ebisawa, Toru

Article Type: Research Article

Abstract: Neutron spin echo (NSE) methods with resonance spin flippers have been developed for 10 years. There are two types of spin echo methods using resonance spin flipper: Neutron resonance spin echo (NRSE) and Mieze. For spallation neutron source like J-PARC, provided that high-frequency neutron spin flippers and appropriate calibration for field integral are realized, NRSE is more suitable than conventional spin echo method since, (1) NRSE can be small and hence it is possible to install two or more spectrometers in one beam line, (2) magnetic shielding over precession region, which is expected to be necessary under huge iron shielding …around the sputter source, is possible. The authors suggest a set of NRSE spectrometers and Mieze spectromter sharing one beam line, in which neutrons are separated according to their wavelength range. This system will cover very wide range of Fourier time and will open new applications to NSE method. Show more

Keywords: Neutron, Spin echo spectrometer, Resonance flipper, Fourier time

DOI: 10.1080/10238160412331299915

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 107-111, 2005

Authors: Aizawa, Kazuya

Article Type: Research Article

Abstract: We propose a TOF-type double-crystal ultra-small-angle neutron scattering (USANS) instrument in JSNS. The fundamental arrangement of the TOF-type USANS instrument is the same as a reactor-type USANS instrument. The feature of this instrument is the simultaneous use of harmonics, λ/n (λ is the neutron wavelength, n = 1, 2, 3...). As a result, the covered q-range (q = (4π sin (φ/2))/λ where φ is the scattering angle) is extended towards both lower and higher qs than that of a reactor USANS instrument. In addition, an effective intensity gain is achieved by harmonics multiplication. We calculated the performance of the TOF-type …USANS instrument on the coupled liquid hydrogen moderator in JSNS. Show more

Keywords: Pulsed neutron, TOF, USANS, JSNS

DOI: 10.1080/10238160412331299906

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 113-118, 2005

Authors: Skoy, V.R. | Masuda, Y. | Muto, S. | Ino, T. | Kim, G.N.

Article Type: Research Article

Abstract: T violation can be related with the CP-violation through Luders–Pauli’s CPT theorem, which is related with a local Lorentz invariant field theory. The CP violation was discovered experimentally in the K0 -meson decays about 35 years ago. The T violating interaction related with the CP violation violates parity as well. However, an extension of the theory beyond the locality of the interactions might violate the CPT theorem. The result of CPLEAR experiment [Angelopolos A. et al., (1998), “First direct observation of time-reversal non-invariance in the neutral-kaon system”, Phys. Lett. B 444 43], which has given direct evidence of T violation …in the elementary-particle phenomena, could be considered under assumption of the CPT invariance. Show more

Keywords: Time reversal invariance, Polarized nuclei, Polarized neutrons, Neutron transmission

DOI: 10.1080/10238160412331299573

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 119-122, 2005

Authors: Suzuya, Kentaro | Kameda, Yasuo | Otomo, Toshiya | Yoshida, Koji | Itoh, Keiji | Fukunaga, Toshiharu | Misawa, Masakatsu

Article Type: Research Article

Abstract: The design, performance, philosophy, lessons learned and advantages of the neutron total scattering spectrometer for hydrogenous materials, FAST, under consideration for the J-PARC-JSNS, are described. In particular, novel instrumentation concept such as the small fractional scattered neutron flight path, γ = L2 /(L1 + L2 ), where L1 is the incident flight path, moderator to sample, L2 is the scattered neutron flight path from sample to detector, is presented and their expected performance at the JSNS is considered.

Keywords: Neutron total scattering, Hydrogenous materials, Inelasticity effect, Third-generation pulsed neutron source

DOI: 10.1080/10238160412331299898

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 123-128, 2005

Authors: Yamaguchi, T. | Takamuku, T. | Soper, A.K.

Article Type: Research Article

Abstract: Neutron diffraction with isotopic substitution measurements have been made at room temperature on seven isotopically substituted ethanol–water mixtures at 0.1, 0.2 and 0.4 ethanol mole fractions, respectively, from which nine composite partial structure factors, HH, HX and XX (X denotes the weighted sum of non-substituted atoms) were derived on water–water, water–ethanol and ethanol–ethanol interactions for each of the solutions. The partial structure factors were then subjected to an empirical potential structure refinement simulation to derive all site–site pair correlation functions. An origin of the so-called microinhomogeneities in ethanol–water mixtures has been established at the molecular level on the basis of …the pair correlation functions, which probably underlines the mechanism of anomalous behaviors in physico-chemical quantities and alcohol-induced denaturation of proteins in ethanol–water mixtures. Show more

Keywords: Solvent clusters, Ethanol–water mixtures, Microinhomogeneities, Neutron diffraction, Hydrogen bonding, Hydrophobic interaction

DOI: 10.1080/10238160412331299889

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 129-133, 2005

Authors: Kato, Y. | Kawakita, Y. | Shibata, K. | Takeda, S. | Pilgrim, W.-C.

Article Type: Research Article

Abstract: Quasi-elastic neutron scattering measurements of liquid germanium were carried out at 1000 and 1500°C, using the inverted geometry inelastic neutron spectrometer, LAM-40. The dynamic structure factor, S(Q,E), is obtained over a wide momentum transfer region from 0.6 to 5.1 Å−1 .

Keywords: Germanium, Liquid, Dynamics, Quasi-elastic, Inelastic, Neutron

DOI: 10.1080/10238160412331299870

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 135-137, 2005

Authors: Iwadate, Y. | Tani, Y. | Fukushima, K. | Misawa, M. | Fukunaga, T. | Itoh, K. | Nakazawa, T.

Article Type: Research Article

Abstract: Pulsed neutron diffraction was carried out to analyze an intramolecular structure of D3 PO3 and an orientational characteristic of adjacent molecules in D3 PO3 –n D2 O(n = 0, 1 and 20) solutions by using the high intensity total scattering spectrometer in High Energy Accelerator Research Organization (KEK) at Tsukuba, Japan. The radial distribution method and the correlation method were employed for the analysis of structural parameters such as interatomic distances, coordination numbers and temperature factors, being consulted with those by simulations. The intramolecular structure of the phosphorous acid in the liquid state did not differ much from that …in the crystalline state. In the liquid phosphorous acid, two intramolecular P–O bonds were recognized, the shorter P–O bond being assigned to the P–O double bond and the longer P–O to the single bond. On addition of heavy water, the coordination numbers of the intramolecular P–O correlations, i.e. both the shorter P–O double bond and the longer P–O single bond, increased a little. Show more

Keywords: Pulsed neutron diffraction, Intramolecular structure, Orientation, Phosphorous acid

DOI: 10.1080/10238160412331299582

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 139-144, 2005

Authors: Kartini, E. | Arai, M. | Iwase, H. | Yokoo, T. | Itoh, K. | Kamiyama, T. | Purnama, S.

Article Type: Research Article

Abstract: New superionic glasses (CuI)x (AgPO3 )1–x with x = 0.1, 0.2 and 0.3 have been prepared by rapid quenching method. Neutron diffraction experiments have been performed by a HIT-II spectrometer at the Neutron Spallation Source, KEK, Japan. A small first diffraction peak at low Q around 0.8 Å was observed in the structure factor for x = 0.2 and x = 0.3, but for x = 0.1 it shows only a shoulder that is similar to the undoped glass AgPO3 . Three new peaks appear at the radial distribution function of (CuI)x (AgPO3 )1–x at ∼ 1.9, 2.7 …and 3.4 Å, that may correspond to the Cu–O, Cu–I and Cu–Cu pair correlations, respectively. Those peaks increase with the amount of CuI. These results indicate that there are two different kinds of Cu atoms. Cu–I bond in the glass is very similar to that in crystalline α-CuI, and Cu–O bond is very similar to that in Cu2 O insulating crystal. Show more

Keywords: Superionic glasses, CuI–AgPO3, Neutron diffraction, Conductivity

DOI: 10.1080/10238160412331299997

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 145-148, 2005

Authors: Chiba, Ayano | Yao, Makoto | Ohmasa, Yoshinori | Hiejima, Yusuke | Kawakita, Yukinobu | Bennington, Stephen M.

Article Type: Research Article

Abstract: Dynamic structures of liquid Te70 Se30 and Te50 Se50 were investigated by inelastic neutron scattering experiments in the semiconductor-to-metal transition range. The bond-stretching modes for the both liquid mixtures were found to clearly soften when the transition occurs. We discuss the change of static and dynamic structures that accompany the transition.

Keywords: Liquid chalcogens, Selenium, Tellurium, Semiconductor-to-metal transition, Inelastic neutron scattering, Vibrational modes

DOI: 10.1080/10238160412331299988

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 149-152, 2005

Authors: Yamazaki, D. | Soyama, K. | Ebisawa, T. | Tasaki, S.

Article Type: Research Article

Abstract: We have been developing Drabkin energy filters for pulse shaping and energy analysis at the J-PARC spallation neutron source. By installing two Drabkin energy filters in sequence (a double Drabkin filter), subsidiary peaks of the resonant spin-flip are suppressed and pulse shaping could be performed more effectively. In this contribution, simulation results of pulse shaping by a double Drabkin filter for the J-PARC moderators are presented.

Keywords: Spatial neutron spin resonance, Neutron pulse shaping, Spallation neutron source, Drabkin energy filter

DOI: 10.1080/10238160412331299979

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 153-156, 2005

Authors: Skoy, V.R. | Masuda, Y. | Muto, S. | Ino, T. | Kim, G.N. | Jones, G.

Article Type: Research Article

Abstract: A neutron polarizer–analyzer system based on polarized 3 He is being developed at KEK Pulsed Neutron Source for an experiment on time reversal invariance in the nuclear reaction at J-PARC.

Keywords: Optical pumping, Polarized 3He, Polarized neutrons, Polarized photons

DOI: 10.1080/10238160412331299528

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 157-161, 2005

Authors: Mori, K. | Yatsuyanagi, K. | Oishi, K. | Fukunaga, T. | Kamiyama, T. | Ishigaki, T. | Hoshikawa, A. | Harjo, S. | Iwase, K. | Itoh, K. | Kawai, M.

Article Type: Research Article

Abstract: Structure refinements have been carried out on the pure tricalcium silicate (C3 S) and the hydrated C3 S with the D2 O–C3 S mass ratio, which is 0.5, using neutron powder diffraction (NPD). The multi-phase Rietveld analysis of the hydrated C3 S revealed the coexistence with the Ca(OD)2 (trigonal phase) and the unhydrated C3 S (triclinic one). The Ca(OD)2 phase was hardly observed on the NPD patterns in the first ∼6 h of hydration, while the several Bragg reflections of Ca(OD)2 appeared drastically from ∼6 to ∼24 h, and then the hydration reaction rate was gradually suppressed. …We could apply the Avrami-model to the initial hydration reaction process of C3 S. Show more

Keywords: Tricalcium silicate, Neutron powder diffraction, Rietveld analysis, Hydration

DOI: 10.1080/10238160412331299519

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 163-167, 2005

Authors: Purwanto, A. | Kamiyama, T. | Hoshikawa, A. | Harjo, S. | Kartini, E. | Collins, M.F. | Sakuma, T.

Article Type: Research Article

Abstract: Room temperature powder neutron diffractions have been performed to investigate the structure of (AgI)0.8 – (NaPO3 )0.2 and (AgI)0.7 –(NaPO3 )0.3 composites consisting of AgI crystalline precipitated in a glassy NaPO3 network. Unlike (AgI)0.8 –(NaPO3 )0.2 and most silver-based superionic materials, (AgI)0.7 –(NaPO3 )0.3 contains Ag5 IP2 O7 instead of βAgI and less γAgI. The diffuse background levels of both composites are similar and largely dominated by NaPO3 amorphous phase.

Keywords: Neutron, Powder, Diffractometer, Silver, Superionics, Composite

DOI: 10.1080/10238160412331299960

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 169-173, 2005

Authors: Shamoto, Shin-Ichi | Tsubota, Masami | Iga, Fumitoshi | Fåk, Björn | Kajitani, Tsuyoshi

Article Type: Research Article

Abstract: YTiO3 with Tc ∼ 30 K has been studied by the MARI spectrometer with Ei = 130 and 500 meV at T = 5, 40 and 200 K. We have not found any clear orbital excitation in a wide Q–E range (0.5 < Q < 25 Å−1 , 6 < E < 350 meV). The intensity of orbital excitation would be significantly weak in comparison with the phonon.

Keywords: Inelastic neutron scattering, YTiO3, Orbital excitation, Orbiton

DOI: 10.1080/10238160412331299951

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 175-178, 2005

Authors: Christianson, A.D. | Lawrence, J.M. | Riseborough, P.S. | Moreno, N.O. | Pagliuso, P.G. | Bauer, E.D. | Sarrao, J.L. | Bao, W. | Goremychkin, E.A. | Kern, S. | Trouw, F.R. | Hehlen, M.P.

Article Type: Research Article

Abstract: In this work, we study crystalline electric field effects in the heavy fermion superconductor CeIrIn5 . We observe two regions of broad magnetic response in the inelastic neutron scattering (INS) spectra at 10 K. The first corresponds to the transition between the Γ7 groundstate doublet and the first excited state doublet at 4 meV interwoven with a broad quasielastic contribution. The second region corresponds to the transition between the ground state and the second excited state doublet at 28 meV. The large Lorentzian half-widths of the peaks (∼10 meV) calls into question calculations for the specific heat and magnetic …susceptibility that assume sharp crystal field (CF) levels. Consequently, we have calculated the INS spectra and magnetic susceptibility using the Anderson impurity model within the non-crossing approximation including the effects of CF level splitting. Show more

Keywords: Inelastic neutron scattering, Heavy fermions, Kondo effect, Superconductivity, Crystal field splitting

DOI: 10.1080/10238160412331299942

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 179-182, 2005

Authors: Ismunandar, | Kamiyama, T. | Hoshikawa, A. | Zhou, Q. | Kennedy, B.J.

Article Type: Research Article

Abstract: The room temperature structures of the five layer Aurivillius phases A2 Bi4 Ti5 O18 (A = Ca, Sr, Ba and Pb) have been refined from powder neutron diffraction data using the Rietveld method. The structures consist of [Bi2 O2 ]2+ layers interleaved with perovskite-like [A2 Bi2 Ti5 O16 ]2− blocks. The oxides were found to be orthorhombic (space group B2cb) as a consequence of tilting of the TiO6 octahedra coupled with cation displacement. The tilting is a consequence of the mismatch between the Bi2 O2 and perovskite-like layers.

Keywords: Aurivillius phase, Neutron powder diffraction, CaBi4Ti5O18, SrBi4Ti5O18, BaBi4Ti5O18, PbBi4Ti5O18

DOI: 10.1080/10238160412331299933

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 183-187, 2005

Authors: Sato, Taku J. | Shibata, Kaoru

Article Type: Research Article

Abstract: DYANA is an inverted-geometry time-of-flight (TOF) spectrometer proposed for the Japan Proton Accelerator Research Complex (J-PARC) project. Here, we show that by introducing pulse-shaping disk choppers and Si 111 analyzer, a DYANA-type short-incident-flight-path spectrometer can attain a very high energy resolution of 2 µeV, with an acceptable neutron flux at the sample position.

Keywords: Inverted-geometry spectrometer, High-energy resolution, Backscattering, J-PARC

DOI: 10.1080/10238160412331299924

Citation: Journal of Neutron Research, vol. 13, no. 1-3, pp. 189-192, 2005