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